Congress Scientifi c Report - Aula Dental Avanzada · Congress Scientific Report, Issue 3, February...

Congress Scientifi c ReportEAO 26th Annual Scientifi c MeetingM A D R I D , 5 O C T O B E R – 7 O C T O B E R 2 0 1 7

I S S U E 3 | F E B R U A R Y 2 0 1 8

Congress Scientific ReportEAO 26th Annual Scientific MeetingMadrid, 5–7 October 2017

This report provides a summary of 20 principal sessions which took place at the EAO’s 26th annual Scientific Meeting. The report was written by a group of delegates at the meeting who have previously prepared similar summaries for circulation among their friends following past EAO meetings.

As described in the methodology, all speakers were given the opportunity to review and amend the editorial that had been written about their presentation, although a significant minority did not respond to the editors’ requests for feedback. The EAO wishes to emphasise that this is not a peer-reviewed scientific report. It was written by the team of volunteer delegates, albeit with input from a large number of the speakers represented. The contents do not necessarily represent the view of the EAO and readers are responsible for independently evaluating any information contained in the report. Nonetheless, the EAO hopes that the report will provide a useful and informative summary of the proceedings of its 26th annual Scientific Meeting.

Members of the Congress Scientific Report team with Alberto Sicilia, EAO President, at the meeting in Madrid, 2017.

Authored by the Congress Scientific Report Subcommittee 2017

Co-chairs:Lino EsteveAlberto Salgado

Members:Javier AmigóVicente BelvisAmbrosio BernabeuFrancisco CarroquinoPilar CegarraAlfonso Diaz David EsteveGuillem Esteve

Patrick LamarieErnesto LarrivaLuis Miguel SanchezJuan NavarroAna NicolásDaniel RoblesEmilio SánchezAndrés Valdés

Congress Scientific Report, Issue 3, February 20182

ContentsAcknowledgements � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 4Methodology � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 4Copyright � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 4

From standard to advanced protocols of implant placement � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 5The Brånemark legacy, the conservative approach � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 5Evolution of surgical protocols in implant dentistry � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 6Flapless, immediate implant placement in the aesthetic zone � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 8Debate: when should we follow each approach? 10

Evolution of bone regenerative protocols in implant dentistry. Past, present and future � � � � � � � � 11Use of autogenous bone grafts � � � � � � � � � � � � � � � � � � � � � � � � � � � 11Use of bone substitutes and barrier devices � � � � � � � �14

Everything begins with the smile. Aesthetic diagnosis as a keystone of the treatment planning in implant dentistry � � � � � � � � � � � � 16The analogue fundamentals � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 16Complete digital workflow for facially driven restorative dentistry � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 18

Get a taste of the future EAO Master Clinician Courses topics � � � � � � � � � � � � � � � � � �21The formulation of a treatment plan: planned road map or extemporaneous improvisation? � � � � � �21New perspectives on ridge augmentation � � � � � � � � � � 23

The treatment of anterior maxilla with deficient available bone � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 25The treatment of anterior maxilla with deficient available bone � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 25The treatment of the anterior maxilla with deficient availability of bone � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 26The treatment of the anterior maxilla with deficiency of bone � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 28Debate � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 29

The role of provisional restorations in aesthetic implant-supported prosthetic rehabilitations � � � � 30The role of provisional restorations in aesthetic implant-supported prosthetic rehabilitations � � � � � � 30Importance of implant position and emergence profile, the role of provisional restoration � � � � � � � � � � � � 32Tissue management in the anterior zone – when, why and how to achieve it in the area around implants � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 34

Evolution of implant prosthodontics � � � � � � � � � � � � � � � � � � 36Is conventional still future oriented? � � � � � � � � � � � � � � � � � � � 36Is digital the new conventional? � � � � � � � � � � � � � � � � � � � � � � � � � � 37Debate � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 38

Insights into surgical approach to the treatment of peri-implantitis � � � � � � � � � � � � � � � � � � � � � � � 42Apically positioned flaps and implantoplasty � � � � � � 42Flap design based on peri-implant defect characteristics � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 45

Avoid nightmares when restoring the edentulous upper jaw. Is the material the key factor? � � � � � � � � � � 48Avoid nightmares when restoring the edentulous upper jaw� Is the material the key factor? � � � � � � � � � � � � 48Full arch ceramo-metal restorations � � � � � � � � � � � � � � � � � � � 49Full arch zirconia rehabilitations � � � � � � � � � � � � � � � � � � � � � � � � � � �51

How to choose the proper connection and abutment � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 52External connections and no abutments � � � � � � � � � � � � � 52Internal connections and abutments � � � � � � � � � � � � � � � � � � 54

What are the limits of immediate implant placement and immediate restoration? � � � � � � � � � � � � 57The socket without buccal bone wall � � � � � � � � � � � � � � � � � � 57The approach to posterior wide sockets � � � � � � � � � � � � �60

The combination of dental implants and orthodontic therapy in the functional rehabilitation of partially edentulous patients � � � 62Missing incisors: implants vs space closure looking at crucial details � � � � � � � � � � � � � � � � � � � � � � � � � 62The use of implant-supported prostheses to restore function after orthodontic therapy � � � � � � � � � � 64

The restorative treatment of the partially edentulous periodontitis patient � � � � � � � � � � � � � � � � � � � � � � �66The conservative approach � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �66The perio-prostho approach � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �68The implant approach � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �71

The treatment of peri-implant soft tissue deficiencies in the anterior maxilla � � � � � � � � � � � � � � � � � � � � 73Aesthetic problems with implants in the anterior maxilla � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 73Key variables influencing re-treatment outcomes � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 75Presentation of successfully treated clinical cases � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 77Debate � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 79

Liaison for the best patient service. Materials of choice for anterior restorations? � � � � � � � � � � � � � � � � � � � � � � � �80The clinical use of zirconia in restorations in the anterior region � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �80Alternatives to zirconia restorations in the anterior region � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 83

Alternatives to titanium as an implant material and custom-made implants � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 85PEEK implants: ready for clinical use? � � � � � � � � � � � � � � � � � 85Ceramic implants a real alternative to titanium today? Part I: material aspects � � � � � � � � � � � � � � � 87Ceramic implants as a real alternative to titanium today? Part II: clinical outcomes � � � � � � � � � � � �89Are custom-made implants ready for clinical use? � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �90

Congress Scientific Report, Issue 3, February 2018 3

Diagnosis and treatment planning in implant dentistry in light of the prevalence of peri-implant diseases � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 92Diagnosis and treatment planning in implant dentistry in light of the prevalence of peri-implant diseases � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 92Infection control and early detection of peri-implantitis � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 94Focus on implant selection, surgical placement and restorative design � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 97

How to approach the treatment of the patient with hopeless implants � � � � � � � � � � � � � � � � � � � � � � � 100How to approach the treatment of the patient with hopeless implants � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 100Management of hopeless implants in partially edentulous patients in aesthetic areas � � � � � � � � � � � � � � � 101How to approach the treatment of the patient with hopeless implants � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �102How to approach the treatment of the patient with hopeless implants in the totally edentulous maxilla � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 103Debate � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 104

Liaison for the best patient service. Analogue versus digital � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 105The analogue clinician with a combined digital-analogue technician � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 105Liaison for the best patient service� Analogue versus digital � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 108Digital workflow in implants prosthodontics � � � � � � � 110

The biological and clinical keys for periodontal, bone and peri-implant regeneration � � � � � � � � � � � � � � � � 111The biological and clinical keys for periodontal, bone and peri-implant regeneration � � � � � � � � � � � � � � � � � � �111Periodontal regeneration: translating biologic concepts into clinical application � � � � � � � � � � � � � � � � � � � � � � � 112The biological and clinical keys for bone regeneration � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 115The biological and clinical keys for peri-implant regeneration � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 117


Acknowledgements

The EAO would like to gratefully acknowledge the substantial work carried out by the Publishing Bureau in editing this report. The Board of Directors would also like to thank all chairs and speakers who have agreed to share their presentations.

Methodology

The methodology underpinning this report is as follows:

1. A team of dentist delegates volunteered to write the report and arranged to attend all the sessions covered in it during the EAO’s 2017 meeting in Madrid

2. They provided a draft summary of each presentation to the EAO, which arranged for a copywriting team to edit it. This was not a scientific editing process, and instead concentrated on grammar and consistency

3. The editors returned the edited contributions to the dentist delegates highlighting any questions they had4. On receipt of responses to their questions, the editors updated the contributions, then forwarded them to

each of the speakers featured, along with a request for a selection of their slides (selected by the writers)5. Each speaker was emailed up to three times to request their feedback. The majority replied and supplied

slides. Some speakers provided textual corrections but declined to provide copies of their slides6. A small number of speakers did not respond to any of the emails sent to them, and as a result the editorial

on their sessions has not been reviewed by them

Copyright

A number of speakers allowed a selection of their slides to be included in this report. Readers should be aware that copyright in any original content included in these slides remains the property of the speakers, and/or any other third-party copyright holders. These slides must not be circulated other than as part of this report, and should not be copied or reused without the express permission of the relevant speakers.

© 2018 European Association for Osseointegration38 rue Croix des Petits Champs, 75001 Paris, Francewww.eao.org

The Congress Scientific Report is edited and designed by www.publishingbureau.co.uk

Printed in the United Kingdom


The following report summarises the first paper presented during the From standard to advanced protocols of implant placement session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

The Brånemark legacy, the conservative approachMarc QuirynenEAO Congress Scientific Report; (3), 5, 2018.

Biocompatibility and atraumatic treatmentThe guidelines for implant treatment which were defined by Brånemark in the 1970s were divided between two main protocols: surgical and loading. Each included a number of principles which were meticulously observed.

1. Surgical protocols:

� sterile environment � pediculated flap � careful drilling and excessive cooling (to remove

bone chips and prevent over-heating of the drill) � bone tapping � countersink to create space for implant shoulder

to control bone compression � minimally rough surface

2. Loading protocols:

� 6–9 month healing period after tooth extraction � 3–6 month submerged healing period for implant

(to allow osseointegration) before loading � 15–18 month bone remodelling period, during

which a temporary prosthesis was worn

As a result of these conservative protocols, implants had survival rates of up to 99% at 20-year follow-ups.

40 years later: what has changed? (Quirynen et al. 2014)The major difference between the classic protocol and contemporary practices seems to be the extension of implant treatments to all type of patients and indications, rather than limiting treatment to fully edentulous patients.

With regard to timing and loading protocols, current strategies may involve a higher degree of risk. Because of the rise in popularity of immediate placement or immediate loading, long healing periods are no longer considered the norm.

The speaker identified two major changes which have increased the risk of surgical protocols. Today, operators can place implants without the same levels of training which were previously required. On

the other hand, higher levels of bone compression are now much more common, and this may be considered hazardous.

In relation to prosthetic protocols, the speaker highlighted four differences which can be considered ‘high risk’. In particular, cementing prostheses and focusing the design on aesthetics, instead of cleanability.

Implant connections, shapes and dimensions have changed significantly over the past 40 years. Moderately rough surfaces could be considered riskier than machined ones. A recent meta-analysis found significantly lower levels of marginal bone loss (MBL) around machined implant surfaces. It should be noted, however, that the authors of the study could not come to a definitive conclusion about the clinical impact of moderately rough surfaces, given that bone loss is a multifactorial phenomenon (Doornewaard et al. 2017).

Conclusion

The speaker concluded that the sheer number of changes between implant protocols of today and those of the ‘conservative’ Brånemark approach does not allow a straightforward comparison of implant survival or success rates. According to the speaker, this observation is based on common sense, and it cannot be said with certainty whether the increase in complications which has been recently observed can be attributed to these changes.

References

Doornewaard R, Christiaens V, De Bruyn H, Jacobsson M, Cosyn J, Vervaeke S, Jacquet W. Long-Term Effect of Surface Roughness and Patients’ Factors on Crestal Bone Loss at Dental Implants. A Systematic Review and Meta-Analysis. Clin Implant Dent Relat Res. 2017 Apr;19(2):372 –399. doi: 10.1111/cid.12457. Epub 2016 Nov 15.

Quirynen M, Herrera D, Teughels W, Sanz M. Implant therapy: 40 years of experience. Periodontol 2000. 2014 Oct;66(1):7–12. doi: 10.1111/prd.12060. �

This summary was prepared by the EAO Congress Scientific Report rapporteurs and approved by the speaker.

View the full publication at: www.eao.org

Congress Scientifi c Report, Issue 3, February 20186

The following report summarises the second paper presented during the From standard to advanced protocols of implant placement session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

Evolution of surgical protocols in implant dentistryGöran UrdeEAO Congress Scientifi c Report; (3), 6–7, 2018.

From ‘Teeth-in-a-year’ to ‘Teeth-in-an-hour’, we have come a long way.

The original protocol

The original protocol was a ‘belt and braces’ approach, which focused on achieving osseointegration and trying not to lose the implant. The original protocol may be summarised thus: two-stage surgery and delayed loading. After the 3–6 month bone healing period, a period of 2–3 months was observed between abutment connection and delivery of the prosthesis, with total treatment times often lasting up to one year (Figure 1). The main features of the surgery were:

� vestibular incision � counter sink � bone tap

Reusable drills or single-use drills?

Over time, reusable drills lose their sharpness, which leads to increased friction and risk of overheating. Another disadvantage of reusable drills is the diffi culty of removing organic debris and risk of cross contamination. Conversely, single-use drills are always sharp and sterile and, according to the speaker, more cost-effective.

Controlling heat when drilling depends on: sharpness, intermittent motion, low speed, irrigation and drill design. Regarding the design, tri-fl ute burs have been shown to have better cutting effi ciency and heat dissipation than twist drills (Chacon et al. 1997; Cordioli et al. 1997).

Sterile or clean?In a comparison of two operative environments (sterile or clean), no signifi cant differences were found in terms of complications and implant survival rates (Cardemil et al. 2009).

Human error

The importance of the role of the operator in implant survival rates has been confi rmed: more failures are associated with inexperienced surgeons. Other risk factors were discussed, such as: clinicians not following concepts, overestimating their own capabilities, and stress (Lambert et al. 1997; Jemt et al. 2015).

Osseointegration equals stability

Primary stability or mechanical fi xation depends on bone density, implant design and surgical technique. All current implant macro-designs are screw-type, since this shape has been demonstrated to have improved clinical stability.

Regarding the surgical technique, undersized drilling increases stability (Lambert et al. 1997; Jemt et al. 2015). It is widely recognised that excessive torque on implants can result in high levels of strain transmitted to the adjacent crestal bone and may cause bone necrosis (Bashutski et al. 2009).

Lateral loading of a stable implant results in a minimal lateral displacement of the implant in the bone. There is a correlation between this displacement and ISQ values. Different implant designs may report different ISQ values for the same bone density; it is therefore necessary to use pegs which have previously been calibrated to each macro-design (Petersson and Sennerby. 2016).

Teeth-in-a-week

This is a one-stage early loading protocol, also called ‘Nordic bridge’. It requires a bite registration guide and a try-in of teeth made previously. Then, fi xture placement, abutment connection and impressions are performed; after one week the prosthesis can be fi tted (Figure 2). This protocol involves a crestal incision; self-tapping implants placed at bone level; medium rough surfaces; micro-threads; and improved implant-abutment connections.

Figure 1

Urde ©

3-6Month

Healing period

3Weeks

Healing period

1Month

Fabrication

Bone healing & 5 - 8 Months = app. 1 Year

Bone Healing

Congress Scientifi c Report, Issue 3, February 2018 7

Figure 2

Urde ©

1/2Month

Fabrication

One week

Pre-Surgical• Bite registration• Try-in of teeth• Bite registration guide

Figure 3

2 - 24Hours

< 24Hours

Implant

placement

Impression Laboratory

AmotioTemp. Crown

2 - 4Months

Final CrownUrde ©

2 - 4Months

Figure 4

Urde ©

• Pros– Fast & Predictable

• Optimized & Safe implant placement

– Little patient discomfort• Cons

– Extensive Treatment Planning– Radiation– Risk for Over heating– “Disconnect the brain” > More risks– “Costly”

Teeth-now

A one-stage immediate loading protocol for immediate single implants in fresh extraction sockets. The provisional is placed on the same day and the defi nitive prosthesis after 2–4 months (Figure 3).

Same-day-teeth

One of the earliest protocols for edentulous patients is the Brånemark Novum® system using pre-fabricated components to restore function on the same day. However, in 80% of patients, a considerable amount of bone has to be removed, and the results also have poor aesthetics.

The current same-day-teeth protocols are ‘All-on-four’ or the ‘Columbus Bridge’. These use angulated abutments, but have less predictable results than the Nordic Bridge; they are delivered in a day (or at most, within a week).

Teeth-in-an-hour

This protocol is based on guided surgery. Virtual planning allows clinicians to fabricate prostheses

in advance (using digital models) and adjust them chair-side following surgery. It is a fast and predictable procedure, but requires an experienced operator and is costly (Figure 4). Despite associated disadvantages, the digital workfl ow is here to stay.

References

Bashutski JD, D’Silva NJ, Wang HL. Implant compression necrosis: current understanding and case report. J Periodontol. 2009 Apr;80(4):700–4. doi: 10.1902/jop.2009.080581.

Cardemil C, Ristevski Z, Alsen B, Dahlin C. Infl uence of different operatory setups on implant survival rate: a retrospective clinical study. Clin Implant Dent Relat Res 2009; 11:288–291.

Chacon GE, Bower DL, Larsen PE, McGlumphy EA, Beck FM. Heat production by 3 implant drill systems after repeated drilling and sterilization. J Oral Maxillofac Surg. 2006 Feb;64(2):265–9.

Cordioli G, Majzoub Z. Heat generation during implant site preparation: an in vitro study. Int J Oral Maxillofac Implants. 1997 Mar–Apr;12(2):186–93.

Jemt T, Olsson M, Renouard F, Stenport V and Friberg B. Early Implant Failures Related to Individual Surgeons: An Analysis Covering 11,074 Operations Performed during 28 Years. Clin Implant Dent Relat Res 2016, 18: 861–872. doi:10.1111/cid.12379

Lambert PM, Morris HF, Ochi S. Positive effect of surgical experience with implants on second-stage implant survival. J Oral Maxillofac Surg 1997;55(12 Suppl 5):12–18.

Petersson A & Sennerby L. On standard calibration of ISQ transducer pegs. Prerequisites for accurate and comparable RFA measurements. Integration Diagnostics Update 2016;1:1–3. �

This summary was prepared by the EAO Congress Scientifi c Report rapporteurs and approved by the speaker.



The following report summarises the third paper presented during the From standard to advanced protocols of implant placement session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Flapless, immediate implant placement in the aesthetic zoneArndt HappeEAO Congress Scientific Report; (3), 8–9, 2018.

Time is the most valuable thing one can spend. If something can be done in one procedure, why do it in two or more?

Evolution of the concept

Immediate implant placement (IIP) has evolved over a long period of development (Figure 1). Four distinct phases can be identified (Buser et al. 2016):

� 1990–2003: ‘trial and error’ phase � 2003: definition of terminology for timing options.

The first systematic review reports predictability (Chen et al. 2004) and IIP is classified into four types during the ITI 2003 Consensus Conference

� 2008: documentation of mid-facial recession as an aesthetic complication; identification of risk factors (biotype, implant malposition, thin or damaged buccal bone)

� 2013: definition of selection criteria for various treatment options

Current recommendations

Now, IIP is a common indication and the clinician has to base their decision on the patient’s clinical and radiographic data. The consensus statements and recommendations (Morton et al. 2014) which are currently relevant are:

� IIP is considered a complex procedure and has to be performed by experienced clinicians in carefully selected patients

� an intact buccal bone wall must be present after extraction

� a thick gingival biotype is highly recommended � no acute infection can be present � sufficient bone should be present (apically and

palatally) to allow implant placement in the correct 3D position

� flapless techniques can yield better outcomes and lower levels of bone resorption (Boardman et al. 2015; Merheb et al. 2017)

Two different concepts

Treatment concept 1: Immediate implant with immediate provisionalisation (Figure 2). The best combination involves grafting the gap, and an individual healing cap or immediate provisional (Tarnow et al. 2014). However, some mid- to long-term studies have revealed continuing recession of facial soft tissues (Kan et al. 2011; Cosyn et al. 2016).

Treatment concept 2: Immediate implant without immediate provisionalisation (Figure 3). The protocol consists of grafting the gap with anorganic bovine bone mineral (ABBM) and connective tissue graft (CTG) in a vestibular pouch (it is still considered a flapless procedure) and immediate placement in the correct 3D position. There is no immediate loading, but the socket is sealed with the healing cap and the connective tissue graft (Tsuda et al. 2011). An adhesive bridge can be used as a provisional for three months, and then the soft tissue profile can be contoured with the restoration. Good results with lower levels of mucosal recession through the CTG are well documented (Bianchi et al. 2004; Grunder et al. 2011; Boardman et al. 2015; Lin et al. 2014).

Figure 1

Figure 2

Figure 3


The speaker is currently involved in an ongoing study comparing CTG with a xenogene acellular dermal matrix (ADM) in this IIP treatment concept.

Conclusions and degree of evidence

� IIP is a predictable treatment and has been well documented in various clinical reviews (Type I)

� IIP is a technique-sensitive procedure suitable only for patients with optimal anatomical characteristics (Type I)

� CTG used in conjunction with IIP improves soft tissue dimensions while preventing future recession of the mucosal margins (Type II)

� immediate provisionalisation leads to better aesthetic outcomes and soft tissue stability in the short-term, but conflicting data is available on tissue stability >5 years (Type II)

References

Bianchi AE, Sanfilippo F. Single-tooth replacement by immediate implant and connective tissue graft: a 1–9-year clinical evaluation. Clin Oral Implants Res. 2004 Jun;15(3):269–77.

Boardman N, Darby I, Chen S. A retrospective evaluation of aesthetic outcomes for single-tooth implants in the anterior maxilla. Clin Oral Implants Res. 2016 Apr;27(4):443–51. doi: 10.1111/clr.12593. Epub 2015 Mar 29.

Buser D, Chappuis V, Belser UC, Chen S. Implant placement post extraction in esthetic single tooth sites: when immediate, when early, when late? Periodontology 2000. 2016; 73:84–102.

Chen ST, Wilson TG Jr, Hämmerle CH. Immediate or early placement of implants following tooth extraction: review of biologic basis, clinical procedures, and outcomes. Int J Oral Maxillofac Implants. 2004;19 Suppl:12–25.

Cosyn J, Eghbali A, Hermans A, Vervaeke S, De Bruyn H, Cleymaet R. A 5-year prospective study on single immediate implants in the aesthetic zone. J Clin Periodontol. 2016 Aug;43(8):702–9. doi: 10.1111/jcpe.12571. Epub 2016 Jun 13.

Grunder U, Wenz B, Schupbach P. Guided bone regeneration around single-tooth implants in the esthetic zone: a case series. Int J Periodontics Restorative Dent. 2011 Nov–Dec;31(6):613–20.

Kan JY, Roe P, Rungcharassaeng K, Patel RD, Waki T, Lozada JL, Zimmerman G. Classification of sagittal root position in relation to the anterior maxillary osseous housing for immediate implant placement: a cone beam computed tomography study. Int J Oral Maxillofac Implants. 2011 Jul–Aug;26(4):873–6.

Lin GH, Chan HL, Bashutski JD, Oh TJ, Wang HL. The effect of flapless surgery on implant survival and marginal bone level: a systematic review and meta-analysis. J Periodontol. 2014 May;85(5):e91–103. doi: 10.1902/jop.2013.130481. Epub 2013 Oct 23.

Merheb J, Vercruyssen M, Coucke W, Beckers L, Teughels W, Quirynen M. The fate of buccal bone around dental implants. A 12-month postloading follow-up study. Clin Oral Implants Res. 2017 Jan;28(1):103–108. doi: 10.1111/clr.12767. Epub 2016 Jan 8.

Morton D, Chen ST, Martin WC, Levine RA, Buser D. Consensus statements and recommended clinical procedures regarding optimizing esthetic outcomes in implant dentistry. Int J Oral Maxillofac Implants. 2014;29 Suppl:216–20. doi: 10.11607/jomi.2013.g3.

Tarnow D, Chu S, Salama M, Stappert CF, Salama H, Garber DA et al. Flapless Postextraction Socket Implant Placement in the Esthetic Zone: Part 1. The Effect of Bone Grafting and/or Provisional Restoration on Facial-Palatal Ridge Dimensional Change—A Retrospective Cohort Study. Int J Periodontics Rest Dent. 2014 May–Jun;34(3):323 –31

Tsuda H, Rungcharassaeng K, Kan JY, Roe P, Lozada JL, Zimmerman G. Peri-implant tissue response following connective tissue and bone grafting in conjunction with immediate single-tooth replacement in the esthetic zone: a case series. Int J Oral Maxillofac Implants. 2011 Mar–Apr;26(2):427–36. �




The following report summarises the debate which took place during the From standard to advanced protocols of implant placement session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Debate: when should we follow each approach?Marc Quirynen, Göran Urde and Arndt HappeEAO Congress Scientific Report; (3), 10, 2018.

Is training necessary?

Certainly. It has been proven that failures are closely related to the clinician’s level of training. Technology by itself is not enough; clinical expertise and good knowledge of several biological criteria are required to use modern tools in a proper way. General surgical training together with training in a specific implant system is necessary. During this educational period, close supervision is advisable to learn from any errors; training must also be extended to the whole team.

How difficult is IIP?

Immediate implant placement is not a simple treatment. It is especially difficult to perform and manage properly in the aesthetic area. Selection criteria for IIP are mainly based on morphological and anatomical structures. To this end, CBCT scans are an essential prerequisite.

Is it necessary to systematically change the biotype in all the patients?The speakers said that it is clinically advisable to have keratinised tissue in the peri-implant area, particularly in high risk patients. The reason is to have a non-mobile supracrestal tissue surrounding the implants.

Minimal or moderate roughness?

Literature reviews of comparative RCTs do not show significant differences between minimally or moderately rough surfaces in relation to implant success and survival rates.

According to some clinical observations, however, bone loss would be greater and the occurrence of peri-implantitis higher in particular patients if moderately rough surfaces were used (compared to minimally rough surfaces). Although this has not yet been confirmed, the problem here would be how to identify these susceptible patients.

There is no point in switching again from moderate to machined surfaces. The former shorten healing times and allow us to treat more compromised cases. However, in the case of exposed threads in machined surfaces, according to the experience of

the Brånemark Clinic, little to no progression of bone loss is observed, provided that proper maintenance is performed.

A possible future concern for addressing peri-implant health would be optimising the abutment surface characteristics and its degree of polishing.

Tissue-level or bone-level?

When asked if biological complications are greater or more frequent in tissue- or bone-level implants, as well as if there are different long-term outcomes between the two, the speakers indicated that additional research on this topic is needed.

External or internal connection?

Saucerisation is a common radiological technique finding when using an external hex. External connections have demonstrated higher levels of marginal peri-implant bone loss; this may be due to weaker mechanical behaviour. Internal connections are superior.

Screw or cement?

Although more frequent technical problems have been associated with screwed prostheses, they have fewer biological complications than cemented ones. Cementing requires superficial margins; the use of customised abutments; and the ability to thoroughly control any possible excess cement.

Patient preparation for surgery

The current protocol for surgical field preparation is: mild disinfection of the patient’s skin and coverage of as much of their face as possible (without covering the nostrils). The patient should not be touched with gloves, and the whole team should be well trained.

Supportive treatment?

Supportive treatment for patients receiving implant therapy is becoming increasingly important. This is due to the increasing rates of peri-implantitis and the negative consequences of explantation. Now, supportive therapy is considered crucial. �

This summary was prepared by the EAO Congress Scientific Report rapporteurs and approved by the speakers.



The following report summarises the first paper presented during the Evolution of bone regenerative protocols in implant dentistry. Past, present and future session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

This session, which was broadcast live from Madrid as part of the EAO’s ‘Online Congress’, was accessible on the association’s Facebook page. The speakers explored different approaches for bone regeneration.

To introduce the session, the chairs emphasised that the evidence-base for short and narrow implants is continually growing and evolving. As a result, traditional indications for bone augmentation procedures are also changing. In spite of the limitations of short and narrow implants, patients’ concerns about morbidity, time and cost mean that it is necessary to consider all options to make an informed decision.

Different approaches have been suggested to mitigate bone deficiency. There are, however, several ‘open’ questions to be discussed:

� how much bone is needed around an implant restoration? � when should vertical augmentation be recommended? � autogenous or allogeneic blocks? � non-resorbable or resorbable membranes? � do we have any evidence-based knowledge on the prevalence of peri-implantitis in regenerated bone?

Use of autogenous bone graftsFederico Hernández-AlfaroEAO Congress Scientific Report; (3), 11–13, 2018.

Pre-prosthetic surgery should follow the ‘PUR’ strategy: preserve the bone we have; use the available existing bone; and reconstruct what the restoration requires. The speaker presented several examples of preservation and the use of bone grafts in clinical cases before focusing on the session’s main topic: bone reconstruction.

According to the latest systematic reviews, the current views on bone reconstruction can be outlined as follows (Milinkovic & Cordaro 2014; Sanz-Sánchez et al. 2016; Elnayef et al. 2017):

� various techniques can be used to augment bone horizontally and vertically, but it is unclear which are the most efficient

� alveolar ridge augmentation procedures may be more technique- and operator-sensitive than other surgical treatments

� priority should be given to simpler and less invasive approaches, which involve fewer complications and take less time to achieve results

Thus each team should use existing evidence from the literature, but should also use its own experience and skills to treat deficiencies. The speaker then shared his own team’s protocol.

Cawood class III atrophy: rounded ridge

Cases involving class III atrophy (‘rounded ridge’) can be treated with narrow implants. These implants however, may not be the best indication for the aesthetic zone or for the posterior mandible.

The speaker’s suggested alternative was to perform a horizontal split crest with simultaneous implant

placement. This may provide an efficient and predictable approach (Mestas et al. 2016; Altiparmak et al. 2017; Waetcher et al. 2017).

A flap is raised, avoiding the need to detach the periosteum more than 5mm. Osseous incisions are made using piezosurgery and space is gained by separating the cortical walls. Implants are placed; the gaps are filled with particulated graft; and a membrane is applied to the occlusal area. After suturing, the implants remain covered.

In the anterior maxilla, the speaker described a delayed protocol to ensure proper positioning of implants. The critical step in this technique is to separate the mucosa from the periosteum. This allows the wound to be closed completely. It has also been shown that higher levels of bone width can be achieved with a partial thickness flap (4.13 ± 3.13mm) than with a full thickness flap (3.19 ± 1.19mm.

Cawood class IV atrophy: knife-edge

Class IV atrophy (as described by Cawood) occurs when both cortical walls are fused with no spongious bone between them, thus making it impossible to perform a splitting technique. The best approach for these cases involves lateral augmentation using autogenous bone-blocks. Excellent long-term results for this technique have recently been documented (Chappuis et al. 2017).

When treating knife-edge ridges in the posterior mandible, bone-blocks can be harvested from the nearby ramus. The empty spaces surrounding the blocks are filled by particulate biomaterials. Blocks


should always be protected by a collagen membrane (so it is also a sort of GBR). As autogenous bone releases growth factors (Caballé-Serrano et al. 2014; Caballé-Serrano et al. 2016), bone formation is faster and means that implants can be loaded after a shorter time-period than GBR, or even immediately.

In some cases, the recipient site has to be flattened. Instead of grinding both the bony bed and the block surface to achieve a congruent flat surface, a thin layer of biomaterials can be placed between the block and the recipient site. This also helps increase bone volume. Whenever possible, no releasing incisions should be made. The recipient bone should be decorticated and the biomaterial compacted like cement to prepare a flat surface to receive the block; finally, the area is covered by a membrane. The speaker emphasised that correct management of soft tissue is critical for obtaining primary closure.

In the re-entry surgery, removal of the screws and implant placement can often be performed transmucosally.

Cawood class V atrophy: maxillary atrophy

In cases involving edentulous patients with full class V atrophy, bilateral sinus lifts are performed. Reconstruction is also performed using blocks from the ramus in more than 90% of cases. In other cases, the speaker emphasised that he prefers to obtain the blocks from the calota, rather than blocks harvested from the hip. In 10 out of 14 cases reported in a clinical study treated using this technique (Hernández-Alfaro et al. 2013), it was possible to place and load implants immediately, thereby shortening the treatment time.

The use of allogeneic bone-blocks has been associated with a large number of complications. A recent review reported bad results (Monje et al. 2014), and this was corroborated in the speaker’s own experience.

Cawood class V atrophy: vertical atrophy

When treating large defects in the anterior zone, the speaker described his approach which involves using previously individualised titanium mesh and GBR instead of bone-blocks. The mesh provides a

‘tent effect’, protecting the particulate graft (a 50% mixture of autogenous bone and biomaterial). The area is then covered by a collagen membrane or by an acellular dermis matrix. The speaker reiterated that soft tissue management is crucial for preventing premature exposures, and should in fact be done at the beginning of the procedure in order to prevent bleeding when suturing.

The speaker also described a technique for preventing mesh exposure. This involves preparatory surgery to improve the condition of the soft tissue and reinforce the flaps three months before augmentation. Following this, wounds seem to be less prone to dehiscence.

The speaker described his process for treating atrophy in the posterior mandible. An inlay bone graft (‘sandwich’ technique) is performed with an incision in the vestibule and biomaterial is inserted between the upper bone fragment and the basal bone to maintain space. A distance of at least 2mm from the nerve is required for the technique. Compared to vertical augmentation by GBR, the sandwich technique has the following advantages:

� management of the soft tissue is easier � the situation is better for bone formation

and no autogenous bone is needed, just an osseoconductive biomaterial works well

� bone is denser and more mature, and the six-month period before implant placement is shorter

The speaker’s group reported fewer complications with the sandwich technique than with GBR. Their documented results are very satisfactory (Felice et al. 2008; Brandtner et al. 2014; Laviv et al. 2014).

The speaker concluded by summarising the proposed protocols for each class of atrophy.


References

Altiparmak N, Akdeniz SS, Bayram B, Gulsever S, Uckan S. Alveolar Ridge Splitting Versus Autogenous Onlay Bone Grafting: Complications and Implant Survival Rates. Implant Dent 26 (2), 284–287. 4 2017.

Brandtner C, Borumandi F, Krenkel C, Gaggl A. A new technique for sandwich osteoplasty with interpositional bone grafts for fixation. Int J Oral Maxillofac Implants. 2014 Sep–Oct;29(5):1164–9. doi: 10.11607/jomi.3185.

Caballé-Serrano J, Bosshardt DD, Buser D, Gruber R. Proteomic analysis of porcine bone-conditioned medium. Int J Oral Maxillofac Implants. 2014 Sep–Oct;29(5):1208–15d. doi: 10.11607/jomi.3708.

Caballé-Serrano J, Fujioka-Kobayashi M, Bosshardt DD, Gruber R, Buser D, Miron RJ. Pre-coating deproteinized bovine bone mineral (DBBM) with bone-conditioned medium (BCM) improves osteoblast migration, adhesion, and differentiation in vitro. Clin Oral Investig. 2016 Dec;20(9):2507–2513. doi: 10.1007/s00784-016-1747-x. Epub 2016 Feb 15.

Chappuis V, Cavusoglu Y, Buser D, von Arx T. Lateral Ridge Augmentation Using Autogenous Block Grafts and Guided Bone Regeneration: A 10-Year Prospective Case Series Study. Clin Implant Dent Relat Res. 2017 Feb;19(1):85–96. doi: 10.1111/cid.12438. Epub 2016 Jul 31.

Elnayef B, Monje A, Gargallo-Albiol J, Galindo-Moreno P, Wang HL, Hernández-Alfaro F. Vertical Ridge Augmentation in the Atrophic Mandible: A Systematic Review and Meta-Analysis. Int J Oral Maxillofac Implants. 2017 Mar/Apr;32(2):291–312. doi: 10.11607/jomi.4861.

Felice P, Marchetti C, Piattelli A, Pellegrino G, Checchi V, Worthington H, Esposito M. Vertical ridge augmentation of the atrophic posterior mandible with interpositional block grafts: bone from the iliac crest versus bovine anorganic bone. Eur J Oral Implantol. 2008 Autumn;1(3):183–98.

Hernández-Alfaro F, Sancho-Puchades M, Guijarro-Martínez R. Total Reconstruction of the Atrophic Maxilla with Intraoral Bone Grafts and Biomaterials: A Prospective Clinical Study with Cone Beam Computed Tomography Validation. Int J Oral Maxillofac Implants 2013;28:241–251. doi: 10.11607/jomi.2405.

Laviv A, Jensen OT, Tarazi E, Casap N. Alveolar sandwich osteotomy in resorbed alveolar ridge for dental implants: a 4-year prospective study. J Oral Maxillofac Surg. 2014 Feb;72(2):292–303. doi: 10.1016/j.joms.2013.09.036. Epub 2013 Oct 5.

Mestas G, Alarcón M, Chambrone L. Long-Term Survival Rates of Titanium Implants Placed in Expanded Alveolar Ridges Using Split Crest Procedures: A Systematic Review. Int J Oral Maxillofac Implants. 2016 May–Jun;31(3):591–9. doi: 10.11607/jomi.4453.

Milinkovic I & Cordaro L. Are there specific indications for the different alveolar bone augmentation procedures for implant placement? A systematic review. Int J Oral Maxillofac Surg. 2014 May;43(5):606–25. doi: 10.1016/j.ijom.2013.12.004. Epub 2014 Jan 19.

Monje A, Pikos MA, Chan H, Suarez F, Gargallo-Albiol J, Hernández-Alfaro F, Galindo-Moreno P, and Wang H. On the Feasibility of Utilizing Allogeneic Bone Blocks for Atrophic Maxillary Augmentation. BioMed Research International, vol. 2014, Article ID 814578, 12 pages, 2014. doi:10.1155/2014/814578

Sanz-Sánchez I, Ortiz-Vigón A, Sanz-Martín I, Figuero E, Sanz M. Effectiveness of Lateral Bone Augmentation on the Alveolar Crest Dimension. A Systematic Review and Meta-analysis. J Dent Res. 2015;94:128S–142S.

Waechter J, Leite FR, Nascimento GG, Carmo Filho LC, Faot F. The split crest technique and dental implants: a systematic review and meta-analysis. Int J Oral Maxillofac Surg. 2017. Volume 46, Issue 1, 116–128. �




The following report summarises the second paper presented during the Evolution of bone regenerative protocols in implant dentistry. Past, present and future session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

This session, which was broadcast live from Madrid as part of the EAO’s ‘Online Congress’, was accessible on the association’s Facebook page. The speakers explored different approaches for bone regeneration.

To introduce the session, the chairs emphasised that the evidence-base for short and narrow implants is continually growing and evolving. As a result, traditional indications for bone augmentation procedures are also changing. In spite of the limitations of short and narrow implants, patients’ concerns about morbidity, time and cost mean that it is necessary to consider all options to make an informed decision.

Different approaches have been suggested to mitigate bone deficiency. There are, however, several ‘open’ questions to be discussed:

� how much bone is needed around an implant restoration? � when should vertical augmentation be recommended? � autogenous or allogeneic blocks? � non-resorbable or resorbable membranes? � do we have any evidence-based knowledge on the prevalence of peri-implantitis in regenerated bone?

Use of bone substitutes and barrier devicesIstvan UrbanEAO Congress Scientific Report; (3), 14–15, 2018.

GBR techniques were developed to treat single missing teeth in a predictable way. But now, these techniques have been applied to larger and more complex defects. Although these severe cases are beyond the traditional indications for GBR, the speaker declared that they can be predictably treated with the current technique.

Particulated grafts

Particulated bone grafts are easy to adapt to an irregular bone surface and they can experience rapid vascularisation and incorporation. The management of complications with particulated bone grafts seems to be more successful than with bone blocks. It was found that augmented bone behaves like native bone, regardless of jaw location and length of defect span after five years of loading (Urban et al. 2009; Merli et al. 2014; Simion et al. 2016). The same observation was made in another study on severe atrophic maxillae with 15-years of follow-up (Urban et al. 2017).

Adding autogenous bone to the particulated graft was found to encourage more bone growth and less shrinkage in a recent split-mouth RCT (Mordenfeld et al. 2014). Currently, the speaker recommends a 1:1 mixture of autograft and xenograft based on two reasons:

� to reduce invasiveness as much as possible � to ensure more bone formation and with more

volumetric stability

This 1:1 mixture has been clinically (Simion et al. 2006; Urban et al. 2011; Urban et al. 2013) and histologically (Rocchietta et al. 2015) validated.

Membranes

In cases involving horizontal defects, the speaker uses collagen membranes; in vertical defects, dense d-PTFE membranes.

Technique

The most critical step is the management of the flaps. In the lingual flap the mucosa should be separated from the mylohyoid muscle. An additional, superficial dissection in both flaps increases their mobility to achieve a complete tension-free closure, providing that the flap is properly sutured.

After the incision is made, bone can be harvested by scraping the ramus. The bony bed is then decorticated using a special bur equipped with a stop. The operator can then wrap a collagen membrane (stretched out with titanium tacks) around the graft material (1:1 mixture of autograft and xenograft) until the membrane is tightly bound. This is the so-called ‘sausage technique’, which refers to the way in which the bone graft is immobilised (Urban et al. 2013).

A six-month waiting period is usually considered appropriate for horizontal augmentation; the


speaker suggested a nine-month waiting period for cases involving vertical augmentation.

The anterior maxilla can be treated with a similar technique. This area can be categorised into four types, based on the depth of the vestibule and the quality/integrity of the periosteum (Urban et al. 2016). The speaker then described his approach for re-entry surgery: a mini-sausage technique performed with autogenous bone surrounding the implants, to help prevent post-surgical bone loss in the peri-implant area; then, a muco-gingival line reconstruction (as the vestibule is almost completely

lacking), which is done in a less invasive way than traditional extensive soft tissue grafts.

Complications

The speaker reported that he has not encountered complications in more than 2–3% cases involving both vertical augmentation and sinus-grafting procedures. Although severe and aggressive infections can occur, they usually present as a fistula with a subacute infection process. In these cases it is possible to re-open the surgical area and clean the infected areas, while maintaining the rest.

References

Merli, M., Moscatelli, M., Mariotti, G., Rotundo, R., Bernardelli, F., Nieri, M. Bone level variation after vertical ridge augmentation: resorbable barriers versus titanium-reinforced barriers. A 6-year double-blind randomized clinical trial. Int J Oral Maxillofac Implants. 2014;29:905–913.

Mordenfeld A, Johansson CB, Albrektsson T, Hallman M. A randomized and controlled clinical trial of two different compositions of deproteinized bovine bone and autogenous bone used for lateral ridge augmentation. Clin Oral Implants Res. 2014 Mar;25(3):310–20. doi: 10.1111/clr.12143. Epub 2013 Apr 2.

Rocchietta I, Simion M, Hoffmann M, Trisciuoglio D, Benigni M, Dahlin C. Vertical Bone Augmentation with an Autogenous Block or Particles in Combination with Guided Bone Regeneration: A Clinical and Histological Preliminary Study in Humans. Clin Implant Dent Relat Res. 2015

Simion M, Ferrantino L, Idotta E, Zarone F. Turned Implants in Vertical Augmented Bone: A Retrospective Study with 13 to 21 Years Follow-Up. Int J Periodontics Restorative Dent. 2016 May–Jun;36(3):309–17. doi: 10.11607/prd.2851.

Simion M, Rocchietta I, Kim D, Nevins M, Fiorellini J. Vertical ridge augmentation by means of deproteinized bovine bone block and recombinant human platelet-derived growth factor-BB: A histologic study in a dog model. Int J Periodontics Restorative Dent. 2006;26:415–423.

Urban IA, Jovanovic SA, Lozada JL. Vertical ridge augmentation using guided bone regeneration (GBR) in three clinical scenarios prior to implant placement: a retrospective study of 35 patients 12 to 72 months after loading. Int J Oral Maxillofac Implants. 2009 May–Jun;24(3):502–10.

Urban IA, Monje A, Lozada JL, Wang HL. Long-term Evaluation of Peri-implant Bone Level after Reconstruction of Severely Atrophic Edentulous Maxilla via Vertical and Horizontal Guided Bone Regeneration in Combination with Sinus Augmentation: A Case Series with 1 to 15 Years of Loading. Clin Implant Dent Relat Res. 2017 Feb;19(1):46–55. doi: 10.1111/cid.12431.

Urban IA, Monje A, Nevins M, Nevins ML, Lozada JL, Wang HL. Surgical Management of Significant Maxillary Anterior Vertical Ridge Defects. Int J Periodontics Restorative Dent. 2016 May–Jun;36(3):329–37. doi: 10.11607/prd.2644.

Urban IA, Nagursky H, Lozada JL. Horizontal ridge augmentation with a resorbable membrane and particulated autogenous bone with or without anorganic bovine bone-derived mineral: a prospective case series in 22 patients. Int J Oral Maxillofac Implants. 2011 Mar–Apr;26(2):404–14.

Urban IA, Nagursky H, Lozada JL, Nagy K. Horizontal ridge augmentation with a collagen membrane and a combination of particulated autogenous bone and anorganic bovine bone-derived mineral: a prospective case series in 25 patients. Int J Periodontics Restorative Dent. 2013 May–Jun;33(3):299–307. doi: 10.11607/prd.1407. �




The following report summarises the first paper presented during the Everything begins with the smile. Aesthetic diagnosis as a keystone of the treatment planning in implant dentistry session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

The analogue fundamentalsMauro FradeaniEAO Congress Scientific Report; (3), 16–17, 2018.

Back to the basics

If we want to prevent failures, we have to go back to the basics. Unfortunately, however, the fundamentals of dental prostheses are often overlooked. It must be remembered that the first step of a treatment plan should be to analyse the patient’s aesthetics; the patient’s whole face and their expression should never be forgotten. If the patient has a low smile line, the treatment plan need not involve perfecting the gingival margin. But on the other hand, in more demanding cases involving high smile lines, the gingival line should be the primary focus of the treatment plan.

The speaker outlined five areas which should be covered by an aesthetic analysis (Figure 1):

1. Facial2. Dento-labial3. Phonetic4. Dental5. Gingival

Any horizontal misalignments which may be present can be identified by a facial analysis. At this stage, the alignment between the eyes, lips and incisal borders should be checked. The occlusal plane should always be parallel to the horizon or the inter-pupillary line. This rule is applicable for both fixed and removable prostheses, and in implants and natural teeth. We should therefore consider the patient’s facial lines and to identify the best orientation of the occlusal plane.

When analysing teeth from a dento-labial point of view, we can determine the position of the incisal edge and the amount of tooth exposure (at rest). The incisal edge position is the starting point of the treatment plan for rehabilitations on either natural dentition or implants. To determine the position of the teeth, we should also examine: the smile line; the width of the smile and the labial corridor; the degree of overjet/overbite; the dental midline; phonetics; and the lower labial curve (Figures 2–3).

To achieve an appropriate tooth preparation, an orthodontic or surgical procedure is sometimes required to reduce excess gingival volume. This allows the cervical contours of the teeth to be raised and thus achieve adequate dental length/width proportions of 80% and correct repositioning of the incisal edges (Figure 4). More frequently, there is a lack of gingival volume, and prosthetic compensation should be carried out with pink material.

After identifying the main facial and dento-labial parameters, we can go into further detail for the dental composition and the proportions and angulation of the teeth (Figure 5).

To achieve the planned tooth position, a comprehensive treatment plan which involves

Figure 2

Figure 1

Figure 3

Figure 4


interdisciplinary collaboration between various specialities is sometimes required.

It is essential to record all data during the diagnostic phase. To enable data collection, the speaker outlined an aesthetic checklist which he has compiled. The checklist includes relevant diagnostic data and important communication features to be used by the laboratory. These features have been published in the speaker’s book (Fradeani & Mauro 2004), and are available in GETApp, an app guiding the clinical throughout the digital prosthetic treatment plan in two steps: data collection and data processing.

Diagnostic wax-up and try-in

Corrections identified by the aesthetic analysis are gathered in a diagnostic wax-up. But wax-ups must be done using real data recorded in the patients. Any miscommunication between the technician and the clinician must be avoided in this crucial step.

In cases involving complete rehabilitations, the try-in is the base for the type of prosthesis which the patient needs, regardless of where the implants are. Once the try-in has been approved by the patient and the dentist, it is the dentist who tells the laboratory how much vertical dimension of occlusion (VDO) should be raised and in which jaw(s) (Figure 6).

Increasing VDO

There are several advantages for increasing VDO (Figure 7). In cases involving bruxism, when occlusal morphology has been completely lost, centric relation (CR) is the only reproducible position and hence our point of reference. Increasing VDO from CR augments the functional overjet, thereby improving occlusion. After this, some patients even stop bruxing (Ormianer & Palty. 2009).

According to the speaker, increasing VDO by up to 5mm is a safe and predictable procedure (Abduo 2012). It can also be effective: in 100 cases involving augmented VDO and implant-supported total rehabilitations, the speaker only found 17% of patients still complain about some signs or symptoms by the end of their treatment but these disappeared within a few weeks (Fabbri et al. Submitted). The main difficulty reported by patients was phonetic – they reported problems with pronouncing ‘S’ during the first two weeks.

References

Abduo J. Safety of increasing vertical dimension of occlusion: a systematic review. Quintessence Int. 2012 May;43(5):369–80.

Fabbri G, Bacherini L, Turrini R, Mintrone F, Cannistraro G, Fradeani M. Submitted for publication.

Fradeani M & Mauro M (2004). Esthetic Analysis. A Systematic Approach To Prosthetic Treatment. In Esthetic Rehabilitation in Fixed Prosthodontics. Ed.: Quintessence Publishing Co. Inc.

Ormianer Z, Palty A. Altered vertical dimension of occlusion: a comparative retrospective pilot study of tooth- and implant-supported restorations. Int J Oral Maxillofac Implants. 2009 May–Jun;24(3):497–501. �

Figure 5

Figure 6

Figure 7

This summary was prepared by the EAO Congress Scientific Report rapporteurs.



The following report summarises the second paper presented during the Everything begins with the smile. Aesthetic diagnosis as a keystone of the treatment planning in implant dentistry session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

Complete digital workfl ow for facially driven restorative dentistryChristian CoachmanEAO Congress Scientifi c Report; (3), 18–20, 2018.

Digital technology is ready to help usDigital technology can now be used in a realistic way, every day and in every patient. It can facilitate more effi cient workfl ows and offer higher quality, faster and less expensive results.

Whether we use analogue or digital methods, the principles of treatment remain the same. When planning a dental rehabilitation, a step-by-step procedure should be implemented (Figure 1). First, the treatment should be integrated into the whole body. The restoration must be facially driven, and the aesthetic must harmonise with the lip and facial dynamics. Then, the restoration has to be functionally integrated. A digital approach can make this process easier, simpler and faster.

Digital tools allow us to reproduce mandibular movements which need to be integrated in the design of the restoration, using so-called ‘organic evaluation’. This makes it easier for technicians to understand what is happening in the patient’s mouth. The restoration can then be adjusted in the dynamic records, rather than in the patient’s mouth, thereby reducing the patient’s chair-time.

Smile design: starting with the fi nal outcomeDesigning a facially generated smile is the fi rst step of the treatment plan, and should be done even before considering what is going on in the patient’s mouth. Accordingly, we can then try to adapt the condition of the tissues to the smile design, by integrating aesthetics with function, biology and structure. This in fact reverses the traditional thought-process (which involves assessing the patient’s mouth and then designing their smile). Decisions about the smile design should never be made using static pictures alone, but should also use dynamic records.

Proposed changes (and any mistakes) can be made using the computer, before we even touch the patient. The digital wax-up can then be quickly made, and 3D software makes it easy to understand the relationship between the new design and the patient’s face and mandibular position. Interdisciplinary treatments (Kokich 1996; Spear 1999; Kois 2002) (which involve, for example: orthodontics, periodontics and crown-lengthening) can be planned and tested virtually using 3D simulation software (Figure 2).

Smile design: classifi cation of restorative cases

Based on the smile design, we can classify cases according to treatment diffi culty (Figure 3). This helps to organise our mental process for making treatment decisions.

Once the digital design phase is complete, several questions should be considered in order to proceed from plan to treatment. First, the implant position and vertical dimension must be decided. Next, a strategy for deprogramming the old bite, bite splint and transitional restoration should be determined. Then, when progressing to the fi nal restoration, it

Esthetic & Function IntegrationBIOMECHANICAL PROTECTION

OCCLUSION & INTERCUSPATION111 222 333 444BUCCAL UPPER ARCH

+ FACE

FACIAL ESTHETICS LIP DYNAMICS

INTERMAXILLARY REALTIONSHIP

TMJ & MUSCLE COMFORT

VDO

FUNCTIONAL NEED AND/OR RESTORATIVE CONVINIENCE

ANGULATIONS & GUIDANCES

JAW MOTION FGP00 1111 555CRANIOSACRAL

+ STOMATONATHIC RE EQUILIBRATION

ORTHOPEDIC THERAPY & CHIROPRATIC

Figure 1

interdisciplinary FAciALLY Driven TREATMEnT PLAnninG

Ortho planning 3d digital design & Perio

Figure 2

Restoratice Case Classification guided by Smile Design1.

Only Restorative

3. CR/DVO

Restorative

2. Crown L.

Restorative

4. Implant

Restorative

6. Orthognatic Restorative

No Changes: Tooth position

Gingiva Bite

Move Gingiva

Change Bite Increase VdO

Add Bone

Implants Move

Tooth position Move

Facial profile

5. Ortho

Restorative

Figure 3


should be decided how the guides will be prepared; how the position will be transferred; and how fi nal occlusal adjustments will be performed.

Increasing the occlusal vertical dimension

In most cases, OVD (occlusal vertical dimension) can be increased. This is because it is a safe and convenient technique for providing: more restorative space; better inter-occlusal relationships; and better aesthetics (Rivera-Morales & Mohl 1991; Kois & Phillips. 1997; Spear 2006; Abduo & Lyons 2012). Thus, one of the main reasons for increasing the OVD is not because the patient has lost vertical dimension, but because it simplifi es treatment.

How much distance is required, and by how much it must be increased, depends on the type of malocclusion. This can be planned and tested digitally, before even touching the patient. When augmenting the OVD we should observe the 1:2:3 rule. Increased OVD is then integrated with the angulations of the anterior teeth, and the occlusion, aesthetics and phonetics (Rebibo et al. 2009) (Figures 4–5).

Step-by-step digital

It must be noted that the digital method is not opposed to the analogue method; it is something to add to it. The speaker outlined six steps to follow in a digital process (Figure 6).

The process begins by determining whether the patient needs full body equilibration treatment (such as orthopaedics) before registering the bite. The next step involves creating the facially guided smile design and the vertical dimension. The digital design is then 3D-printed and dynamically tested in the patients mouth as a ‘motivational’ mock-up.

This aesthetic design must then be integrated into the function with the use of bite registrations which are uploaded to the software. The fi rst detected occlusal point of contact gives us an idea of how much vertical augmentation is required. The objective is to design two models in occlusion to create the digital aesthetic and functional wax-ups.

At this point, the speaker superimposed the digital wax-up over the original facial model, and used the information gathered from this to answer the questions related to the performance of the treatment (Figure 7). In this way, the smile design phase transitions to treatment planning.

Four dying entities in restorative dentistry

The speaker identifi ed four tools which he has predicted will disappear from our offi ces, since digital alternatives are proving much more advantageous (Figure 8): face bows, bite registration materials, articulators and analogue wax-ups. For now, however, these devices are still useful for training purposes and for understanding the principles of digital processes.

Because of its reproducibility, centric relation is the reference point. There are different concepts

and methods for getting to this position. The speaker recommended the Kois Deprogrammer appliance which can be digitally designed and made. After 30 seconds with the deprogrammer in place, the patient’s centric relation can be intra-orally scanned; no bite registration materials are necessary. Furthermore, the restorative vertical dimension must also be included in the digital plan.

POSTERIOR1 MM OVERBITE

2 MMOVERJETOVERJET1,31,3 MM

Open...

INCISAL PIN3 MM

INCISAL PINRebibo M, Darmouni L, Jouvin J, Orthlieb JD. Vertical dimension of occlusion: the keys to decision we may play with the VDO if we know some game’s rules. J. Stomat. Occ. Med. 2009; 2: 147–159

1:2:31:2:3RELATIONSHIP

Figure 4

1 MM 2 MM 3 MM0 4 MM

Figure 5

Function Biology

Structure

Bite Movement Bone/Soft Tissue Movement

Tooth Movement Arch Movement

Reshaping Tooth Prep

Facially Driven Design

CR/VDO

+ =Functional Esthetic Design

Figure 7

STEP 1. OCCLUSION DIAGNOSIS STEP 2. INTEGRATE SMILE DESIGN & FUNCTION STEP 3. DEPROGRAM THE BITE STEP 4. REGISTER NEW VDO & CR STEP 5. TRANSITIONAL RESTORATIONS STRATEGY STEP 6. FINAL RESTORATIONS

Figure 6

4 DYING ENTITES IN RESTORATIVE DENTISTRYAnalogue Face Bow

Analogue Articulator

Analogue Wax up

ANALOGLY TRAINING

DIGITALLY PRODUCING

Bite Registration

Material

Figure 8


The next step is the transitional restorative phase. Transitional restorations are based on the concept developed by Francesca Vailati which involves performing a minimally invasive rehabilitation of worn dentition, combining increased vertical dimension and additive bonded restorations – the

‘three-step technique’ (Vailati & Belser. 2008). The speaker described four approaches for transitioning from 3D functional designs to restorations in the mouth which involve exporting STL fi les (Figure 9):

� a ‘snap-on transitional restoration’ made by CAD/CAM milling; this serves as a reversible diagnostic mock-up

� PMMA milled additive prep-less transitional restorations, which are bonded directly and can be made with high quality, dense materials which can last for a long time in mouth. This also benefi ts the patient from a fi nancial point of view, as there is time before the placement of the defi nite restoration

� STL fi les can be exported to 3D-printing machines to make models, vacuums or silicone trays to fi ll with acrylic; this is a quick, economic and easy approach, however, because it is a splinted restoration, tissue maintenance is not ideal and thus should only be used in the short-term

� injected rehabilitation, which is made with fl ow composite bonded directly through a printed silicone tray

Transitional restorations can serve as a clinical test but they may also be used as a preparation guide (Magne & Belser 2004). For the fi nal restoration, the project is exported to CAD/CAM and the operator can work by sextants in a simple way, alternating between provisional and defi nitive restorations.

One of the advantages of using an intra-oral scanner is being able to analyse the software preparations before sending them to the laboratory. Final occlusion is analysed with the T-scanner, and the restoration can be adjusted. The bite splint will also be fabricated digitally. Figure 10 summarises the digital process.

Software can often surpass humans in terms of performance, precision and effi ciency. Nevertheless, interpretation and the decision-making process are based on scientifi c knowledge and clinical experience. Artifi cial intelligence systems may be close to being able to substitute humans in some areas, but adaptability and creativity require gut feelings and artistic intuition, which can only be achieved by humans.

ReferencesAbduo J1, Lyons K. Clinical considerations for

increasing occlusal vertical dimension: a review. Aust Dent J. 2012 Mar;57(1):2–10. doi: 10.1111/j.1834-7819.2011.01640.x.

Kois J. Diagnostically driven interdisciplinary treatment planning. The Seattle Study Club J. 2002 6(4):28–34.

Kois JC, Phillips KM. Occlusal vertical dimension: alteration concerns. Compend Contin Educ Dent. 1997 Dec;18(12):1169–74, 1176–7; quiz 1180.

Kokich VG. Esthetics: the orthodontic-periodontic restorative connection. Semin Orthod 1996 Mar;2(1):21–30.

Magne P & Belser UC. Novel porcelain laminate preparation approach driven by a diagnostic mock-up. J Esthet Restor Dent 2004;16(1):7–16; discussion 17–8.

Rebibo M, Darmouni L, Jouvin J, Orthlieb JD. Vertical dimension of occlusion: the keys to decision. J. Stomat. Occ. Med. 2009, 2:147. https://doi.org/10.1007/s12548-009-0027-7

Rivera-Morales WC & Mohl ND. Relationship of occlusal vertical dimension to the health of the masticatory system. J Prosthet Dent 1991 Apr;65(4):547–53.

Spear F. The maxillary central incisal edge: a key to esthetic and functional treatment planning. Compend Contin Educ Dent. 1999 Jun;20(6):512 –6.

Spear FM, Kokich VG, Mathews DP. Interdisciplinary management of anterior dental esthetics. J Am Dent Assoc. 2006 Feb;137(2):160–9.

Vailati F & Belser UC. Full-mouth adhesive rehabilitation of a severely eroded dentition: the three-step technique. Part 1. Eur J Esthet Dent 2008 Spring;3(1):30–44. �



direct bonded

indirect bonded

indirect snap on

PRINTERBis-acryl

CAD/CAMPMMA

Flexi PMMA CAD/CAM

PRINTERFlow Composite

direct bonded

STL

Transitional Esthetic/Functional

Restorations

Figure 9

Digital 3D Wax up

Digital Wax up +

Pre op Scan =

Prepless Restorations

Digital Wax up +

Prep Scan =

Prepless Restorations

Final OutcomePre op

Figure 10


The following report summarises the first paper presented during the Get a taste of the future EAO Master Clinician Courses topics session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

This session provided attendees with a flavour of the EAO Master Clinician Courses. Experts from two upcoming courses introduced the topics of their course and how they could benefit clinicians.

The formulation of a treatment plan: planned road map or extemporaneous improvisation?Stefano GracisEAO Congress Scientific Report; (3), 21–22, 2018.

When you are going on a trip, you need a travel plan. In the same way, before starting a dental treatment, you need a well-structured treatment plan (which includes all the steps of the therapy). To illustrate this, the speaker presented a clinical case of a patient who presented with a maxillary anterior crown detached from the non-vital root. For this problem, two possible treatment options had been proposed by different operators: one focused on replacing the crown; the other, on the basis of a complete diagnosis and evaluation of the existing prosthesis, which recommended a complete rehabilitative approach. Of course, the two treatment plans had very different implications, time requirements, costs and, very likely, long-term outcomes.

Pre-treatment steps

The speaker identified three steps which should be always carried out when evaluating a new patient or a new clinical situation:

1. Diagnose the clinical problem(s)2. Formulate the ideal treatment plan and its

alternatives3. Identify the specialists or practitioners to be

involved and the sequence of treatment

1. Diagnostic process (Figure 1)

The first step involves data collection, which is recording all conditions which represent a deviation from a ‘normal’ state of health, noting medical and dental history, performing clinical and radiographic examinations, and, in certain situations, making diagnostic models and mounting them on an articulator.

The speaker recommended a 32-question dental anamnesis formulated by Dr. John Kois to collect a patient’s dental history. The questionnaire is divided into five sections (Figure 2). This allows clinicians to categorise the patient before the clinical exam and anticipate the specific level of risk that the patient may represent in the different areas.

The clinical examination can provide data about: the condition of muscles and TMJs; facial asymmetries; the periodontal situation with plaque and bleeding indexes; and occlusal function. The type of radiographic examination which should be

performed varies depending on the case: in adults, a full-mouth series of intra-oral radiographs is indicated, while a CBCT is indicated in the case of implants and complex extractions.

Diagnostic models mounted in the articulator are also crucial for planning restorations which involve modifications to the upper anterior teeth, the occlusal plane or the entire mouth. It is very important to communicate with the lab technician properly the spatial relationship of the patient’s dental arches: the technician needs to see the same information which you see. To this end, the speaker illustrated a very simple manner to record the position of the maxillary arch with an earbow in the correct spatial framework.

Following a thorough analysis and interpretation of this data, a list of problems can be compiled and, therefore, a full diagnosis can be made. The speaker stressed the importance of also making an occlusal diagnosis so that patients can be assigned to one of five occlusal risk categories (Figure 3).

Figure 1

Figure 2


The next step involves formulating a prognosis (that is, expressing a clinical judgement regarding the possibility to treat the patient properly and the future of each tooth of the patient). The former is based on taking into consideration the patient as a whole with his/her health issues, habits, compliance and ability to clean the teeth. The latter is more specific, and classifies each tooth into: good, questionable or hopeless (irrational to treat) (Figure 4). This judgement is based on the clinician’s knowledge and past experiences. The prognostic opinion is the basis of the treatment plan.

2. Formulation of the plan(s)

The treatment plan has to address all the issues recorded as outlined above, and propose the best solutions as if there were no patient constraints, taking into account the patient’s systemic condition, periodontal susceptibility and tooth prognosis. But we should also provide an alternative (but equally suitable) plan which takes into consideration desires, preferences, time, health or financial limitations set by the patient. Whenever possible, avoid formulating a treatment plan which includes compromises, even if the patient accepts them. The treatment plan will be also be influenced by the clinician’s own experience and his or her preferences/bias.

The speaker suggested the use of a step-by-step list of seven items to analyse, which will help convert the data collected into a treatment plan (Figure 5). The speaker illustrated its use in several clinical examples.

3. Treatment sequence

It is very important for all those involved in the treatment and who work together as a multidisciplinary team to ‘speak the same language’. In order to reach this objective, they need to act in an interdisciplinary way (that is, they need to interact with each other understanding fully what the other team members can do and facilitate their work). This kind of team takes years and effort to be developed.

The strategy and order of treatment steps may differ depending on the circumstances. The correct sequence should be the combined result of the input from the various interdisciplinary specialities.

A number of issues may arise with any treatment plan, such as during provisionalisation and patient re-evaluation. A number of relevant features of treatment phases must be considered in order to sequence treatment steps in the best way for the patient (Figure 6).

Recommendations

� diagnose all the problems of the patients, not only those which they perceive

� do not start an invasive procedure without first having a clear vision of the end result

� assess the patient’s compliance; it is imperative that they understand the treatment programme before treatment begins

� carefully evaluate the prognosis of each natural tooth

� always present a comprehensive and sequenced treatment plan and its alternatives, explaining the pros and cons of each option �



Figure 3

Figure 4

Figure 5

Figure 6


The following report summarises the second paper presented during the Get a taste of the future EAO Master Clinician Courses topics session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

This session provided attendees with a flavour of the EAO Master Clinician Courses. Experts from two upcoming courses introduced the topics of their course and how they could benefit clinicians.

New perspectives on ridge augmentationIstvan UrbanEAO Congress Scientific Report; (3), 23–24, 2018.

In recent years, the use of regenerative procedures radically declined. This may have been due to complications arising from suboptimal techniques. But today, we are once again seeing a rise in GBR. This time, it is based on: a better understanding of the biological principles of the procedure; its proven long-term clinical outcomes; and new technical developments.

GBR is an augmentation technique which is less invasive than hip bone-block grafts. Once the technique has been mastered, its applications can have astonishing results. The speaker showed how cases with severe defects (such as oroantral communication after a car accident, or a vertical anterior defect following implant failure) were successfully treated with GBR.

The posterior mandible

The severely atrophic posterior mandible is a common indication for vertical GBR. Clinical results free of complications can be consistently achieved, provided that the minutiae of the technique are carefully observed.

Good tissue closure is not easy to achieve, since proper management of both the lingual and buccal flaps is required to attain flap-free wound closure. Currently, the advancement of the flaps should be performed micro-surgically, to protect the lingual and mental nerves. Advancement is achieved by making superficial incisions in the connective tissue, while keeping the muscle intact. The speaker stated that the technique is so minimally invasive that patients need much less or, in some cases, no painkillers at all.

The current increased uptake of GBR is partially based on findings from anatomical investigations on cadavers recently published (Urban et al. 2017). An in-depth understanding of anatomical variations in the vascularisation of the sublingual space is necessary to protect vulnerable arteries. On the other hand, the shape of the mylohyoid line and the different levels of insertion of the muscle must be fully understood. This anatomical pattern has led the speaker to devise a modified lingual flap advancement technique (Urban et al. 2018).

Lingual pinning can be made easier by first fixing the occlusal membrane so that it does not move. Then, the occlusal pin is removed to put the particulated graft under the membrane and then pin it buccally. A similar approach can be taken in the anterior mandible as well.

The anterior maxilla

An extremely complex area, the surgical management of the anterior maxilla depends on various factors: biotype; vestibular depth; amount of keratinised tissue; neighbouring periodontal bone levels; tissue flexibility; and potential sources of infection. But the most important factor is (once again) flap closure. Regarding the conditions of flap closure, the speaker outlined a four-type surgical classification system which has been formulated by himself and his co-workers:

� shallow vestibule with healthy periosteum � deep vestibule with healthy periosteum � shallow vestibule with scarred periosteum � deep vestibule with scarred periosteum (Urban

et al. 2016)

In severe vertical anterior defects, the speaker described a combined approach which involves lateral and coronal flap advancement to enable tension-free closure: the ‘papilla shift technique’, combined with a suborbicularis preparation of the coronal flap. A periosteoplasty can also often be performed to make the scar tissue more flexible.

The soft tissues

In many cases we have to keep in mind that anterior maxillary augmentation can cause a major distortion in the vestibule and muco-gingival junction, and can therefore limit the lip mobility. In these cases, there is no keratinised tissue, and the vestibule is now occupied by loose fibres. To solve this problem, we do not perform a ‘giant’ autogenous free gingival graft anymore. Now, we use the strip/CMX combination graft technique (Urban et al. 2015). In this technique, a thin gingival strip is sutured to the most apical extension of the prepared periosteal bed, covering the remaining exposed periosteum with a xenogeneic collagen matrix. This approach can offer much a more promising colour and aesthetic appearance of the resulting tissues.


Conclusions

� vertical ridge augmentation with GBR is safe and predictable

� favourable long-term clinical outcomes support the use of GBR for ridge augmentation

� soft tissue reconstructive surgery may be necessary in demanding defects and there is new evidence supporting the use of minimally invasive surgical procedures

References

Urban IA, Lozada JL, Nagy K, Sanz M. Treatment of severe mucogingival defects with a combination of strip gingival grafts and a xenogeneic collagen matrix: a prospective case series study. Int J Periodontics Restorative Dent. 2015 May–Jun;35(3):345–53. doi: 10.11607/prd.2287.

Urban IA, Monje A, Nevins M, Nevins ML, Lozada JL, Wang HL. Surgical Management of Significant Maxillary Anterior Vertical Ridge Defects. Int J Periodontics Restorative Dent. 2016 May–Jun;36(3):329–37. doi: 10.11607/prd.2644.

Urban IA, Monje A, Wang HL, Lozada J, Gerber G, Baksa G. Mandibular Regional Anatomical Landmarks and Clinical Implications for Ridge Augmentation. Int J Periodontics Restorative Dent. 2017 May/Jun;37(3):347–353. doi: 10.11607/prd.3199.

Urban IA, Traxler H, Romero-Bustillos M, Farkasdi S, Bartee B, Baksa G, Avila-Ortiz G. Effectiveness of Two Different Lingual Flap Advancing Techniques for Vertical Bone Augmentation in the Posterior Mandible: A Comparative, Split-Mouth Cadaver Study. Int J Periodontics Restorative Dent. 2018 Jan/Feb;38(1):35–40. doi: 10.11607/prd.3227. PMID: 29240202. �




The following report summarises the first paper presented during the The treatment of anterior maxilla with deficient availability of bone session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

The treatment of anterior maxilla with deficient available boneJoseph KanEAO Congress Scientific Report; (3), 25, 2018.

The speaker began by describing a clinical case involving three missing incisors and bone deficiencies (horizontal and vertical); the case was treated in 2002 with guided bone regeneration (GBR). The speaker explained that the most important factor for anticipating the outcome of GBR procedures is measuring the amount of bone in the adjacent teeth. In cases requiring vertical augmentation, papillae can be lengthened by only about 11% of the total height of the crowns.

Surgical and prosthodontics integration

In another case described by the speaker, augmentation was performed using a titanium mesh. He explained that if the mesh was exposed, the prognosis of the closure would be good.

The incision was made high in the vestibule, above the muco-gingival line. Next, two releasing incisions were made and extended along the sulcus of the adjacent teeth. The flap was deeply dissected towards the palate. In this way, enough tissue could be obtained to cover the augmentation site. Titanium mesh was fixed in, filled with particulated biomaterial, and then covered by fibrin membranes and sutured in two planes.

The rest of the treatment was performed using ovate pontics in various provisionals. The speaker reported that the case has improved over time.

The benefit of this technique is that it can offer an easy closure, however it can also often lead to unaesthetic scars in the vestibule. �




The following report summarises the second paper presented during the The treatment of anterior maxilla with defi cient availability of bone session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

The treatment of the anterior maxilla with defi cient availability of boneLuca De StavolaEAO Congress Scientifi c Report; (3), 26–27, 2018.

Usually, there are several options available for treating clinical problems. When deciding which option to follow, the one which is based on biology should be selected. Since cellular reactions are predictable and generally follow the same pattern, both the vascularity and the inductive and mechanical factors have to be considered.

The speaker identifi ed three biological principles:

1. New capillaries are formed before new bone is (Schmid et al. 1997)

2. Bone formation begins on the exposed surfaces of the defect (Schenk et al. 1994)

3. Autogenous bone is the ‘gold standard’ for enabling the formation of new bone (Schmitt et al. 2013)

Drawbacks of bone grafting

The behaviour of autogenous bone grafts can differ depending on their position, and whether the graft is inside or outside the bone envelope (Figure 1). Bone-blocks located outside the anatomical contour may undergo compressing forces; this increases bone remodelling by mechanotransduction and thereby results in resorption.

In a six-year prospective clinical study of bone-blocks it was concluded that individual variations in resorption patterns made bone grafting unpredictable (Jemt & Lekholm. 2005). Another study reported resorption in 60% of bone-blocks from the time of grafting to the time of loading, and resorption in 35% after implant placement with no protection (Widmark et al. 1997).

The speaker also cited a randomised clinical study of the effects of simultaneously placed demineralised bovine bone matrix (DBBM) and collagen membranes on the healing of mandibular bone-blocks. This study showed that DBBM did not achieve osseointegration in 82% of cases, meaning that its long-term durability is questionable (Cordaro et al. 2011).

Bovine bone delayed reliningBased on these studies, the speaker proposed a three-step technique, ‘bovine bone delayed relining’ (De Stavola & Tunkel 2013):

1. An autogenous bone-block is grafted and shaped in plates. This step is based on Khoury’s ‘bony lid approach’ (Khoury et al. 2007), which allows the graft to be vascularised in a shorter period of time than with compact blocks. The graft is placed in accordance with the anatomical contour of the crest

2. Four months later, the implants are placed and the site is grafted with bovine bone and a collagen membrane

3. In a third surgical procedure a soft tissue graft is performed

Guided bone harvesting in the ramus of the mandible is a well-tolerated procedure with low complication rates. The technique has been described in a 10-year prospective clinical study (Khoury & Hanser 2015; Fistarol et al. 2017). A piezoelectric saw can be used, which is guided by a CAD/CAM template previously screwed into place (De Stavola et al. 2015; De Stavola et al. 2017) (Figures 2–3).

Figure 1

Figure 2

Figure 3


Although the primary surgical goal should be to avoid over-contouring the crest, autogenous bone-blocks should never be placed outside the bony envelope (otherwise they will be resorbed). Only a xenograft covered with a collagen membrane (placed during the second step of the technique) can maintain the desired over-contoured volume.

A break-down of the main concepts discussed can be found in Figure 4.

References

Cordaro L, Torsello F, Morcavallo S, di Torresanto VM. Effect of bovine bone and collagen membranes on healing of mandibular bone blocks: a prospective randomized controlled study. Clin Oral Implants Res. 2011 Oct;22(10):1145–50.

De Stavola L, Fincato A, Albiero, AM. A computer-guided bone block harvesting procedure: a proof-of-principle case report and technical notes. Int J Oral Maxillofac Implants. 2015 Nov–Dec;30(6):1409–13. doi: 10.11607/jomi.4045

De Stavola L, Fincato A, Bressan E, Gobbato L. Results of Computer-Guided Bone Block Harvesting from the Mandible: A Case Series. Int J Periodontics Restorative Dent. 2017 Jan/Feb;37(1):e111–e119. doi: 10.11607/prd.2721.

De Stavola L, Tunkel J. A new approach to maintenance of regenerated autogenous bone volume: delayed relining with xenograft and resorbable membrane. Int J Oral Maxillofac Implants. 2013 Jul–Aug;28(4):1062–7. doi: 10.11607/jomi.2726.

Fistarol et al. Posterior mandible anatomy: surgical considerations in relation to bone harvesting procedures. EAO 26th Annual Meeting 2017, Madrid.

Jemt T, Lekholm U. Single implants and buccal bone grafts in the anterior maxilla: measurements of buccal crestal contours in a 6-year prospective clinical study. Clin Implant Dent Relat Res. 2005;7(3):127–35.

Khoury F, Antoun H, Missika P (eds). Bone Augmentation in Oral Implantology (2006) London: Quintessence Pub 2007.

Khoury F, Hanser T. Mandibular bone block harvesting from the retromolar region: a 10-year prospective clinical study. Int J Oral Maxillofac Implants. 2015 May–Jun;30(3):688–97. doi: 10.11607/jomi.4117.

Schenk RK, Buser D, Hardwick R, Dahlin C. Healing pattern of bone regeneration in membrane-protected defects: A histo-logic study in the canine mandible. Int J Oral Maxillofac Implants 1994;9:13–29.

Schmid J, Wallkamm B, Hammerle CH , et al. The signifi cance of angiogenesis in guided bone regeneration: a case report of a rabbit experiment. Clin Oral Implants Res. 1997;8:244–8.

Schmitt CM, Doering H, Schmidt T, Lutz R, Neukam FW, Schlegel KA. Histological results after maxillary sinus augmentation with Straumann® BoneCeramic, Bio-Oss®, Puros®, and autologous bone. A randomized controlled clinical trial. Clin Oral Implants Res. 2013 May;24(5):576–85. doi: 10.1111/j.1600-0501.2012.02431.x. Epub 2012 Feb 13.

Widmark G, Andersson B, Ivanoff CJ. Mandibular bone graft in the anterior maxilla for single-tooth implants. Presentation of surgical method. Int J Oral Maxillofac Surg. 1997 Apr;26(2):106–9. �



Figure 4


The following report summarises the third paper presented during the The treatment of anterior maxilla with deficient availability of bone session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

The treatment of the anterior maxilla with deficiency of boneMarkus HürzelerEAO Congress Scientific Report; (3), 28, 2018.

In the patient’s shoesThe speaker began with a reflection. We should put ourselves in the patient’s shoes and ask ourselves: would we undergo these surgeries to obtain those results? It is important to keep the needs and expectations of patients in mind. Patient-related outcome measures (PROMs) are now important criteria for evaluating treatment protocols.

Patients expect quality and quantity when it comes to peri-implant tissue. In other words, they are looking for perfect results, but we are far from being able to achieve the level of predictability they need.

The socket-shield technique

The idea of retaining the buccal portion of a tooth root during immediate implant placement was first introduced in 2010 as a proof-of-concept report. In an experimental study in the dog model, no interference with osseointegration was found, and the buccal bone plate had been preserved (Hürzeler et al. 2010).

The speaker then described several clinical cases which were treated using the technique. The first involved orthodontic extrusion to improve the patient’s smile, which showed unsatisfactory papillae height and visible black triangles. After 12 months, teeth were extracted and immediate implants were placed, while the buccal shield of the teeth was retained to preserve the hard and soft tissues which had been gained by orthodontic treatment (Figure 1).

The second case involved two crowns on the central incisors: the teeth were cut, and the drilling was made through the roots with the help of a surgical guide. The buccal shield of the roots was then prepared, leaving interproximal portions to maintain papillae

levels. The teeth were then cut and customised to be used as healing abutments. After six months, the final prosthesis was placed (Figure 2).

In the third case, three teeth had to be extracted. Using guided surgery, the drilling was again performed through the centre of the roots. The buccal shield was prepared, and two implants were placed in the first premolar and the lateral incisor; the root of the canine was left in the middle with a connective tissue graft to maintain volume in the area of the pontic. Two customised healing abutments were then placed to protect the sockets and maintain the shape of the tissues.

Promising five-year results with the socket-shield technique have recently been recorded. The tissue volumes were measured by merging the files scanned using dedicated software; the average loss of buccal surfaces, bone and margin recessions were in the range of 0.2–0.3 mm (Baumer et al. 2017).

To summarise, good outcomes have been obtained with this technique: no scars, near perfect morphology, and high patient satisfaction.

References

Bäumer D, Zuhr O, Rebele S, Hürzeler M. Socket Shield Technique for immediate implant placement – clinical, radiographic and volumetric data after 5 years. Clin Oral Implants Res. 2017 Nov;28(11):1450–1458. doi: 10.1111/clr.13012. Epub 2017 Mar 23.

Hürzeler MB, Zuhr O, Schupbach P, Rebele SF, Emmanouilidis N, Fickl S. The socket-shield technique: a proof-of-principle report. J Clin Periodontol. 2010 Sep;37(9):855–62. doi: 10.1111/j.1600-051X.2010.01595.x. �



Figure 1

1

Figure 2

1


The following report summarises the debate which took place during the The treatment of anterior maxilla with deficient available bone session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

DebateJoseph Kan, Luca De Stavola and Markus HürzelerEAO Congress Scientific Report; (3), 29, 2018.

In complex cases, autogenous bone-block reconstruction is the gold standard. This should be followed with a GBR procedure using a xenograft with slow rates of resorption. In some cases, titanium meshes can be also useful.

Regarding soft tissue management in partial thickness flaps, there is controversy between cutting the muscles deeply or superficially (and not cutting nerves which may alter the posterior sensitivity of the patient).

Perhaps an important percentage of the reconstruction’s final volume may be due to soft tissue augmentation and not only gained by bone-block and GBR augmentation procedures performed in the second surgery. This data was reported in a study (Schneider et al. 2011) carried out on horizontal augmentation and non-vertical augmentation, and so we can infer that similar rates can be reached with vertical augmentation. Soft tissue grafting is a key factor for success in the management of any bone deficiency in the aesthetic area. The importance of the soft tissue therefore cannot be underestimated.

The speaker emphasised that the socket-shield technique is still currently under investigation. Its protocol has not been clearly defined or published, and the technique should not be considered a routine clinical procedure.

How can we envisage the future? At the moment, these reconstructions cannot be performed in a less invasive way. Three surgical interventions are currently needed: autogenous bone graft, GBR with xenograft, and soft tissue augmentation. It is important to make an informed decision, knowing the details of the protocol and its alternatives. Perhaps when it is possible to better handle the soft tissue, it could be possible to reduce the number of surgeries.

References

Schneider D, Grunder U, Ender A, Hämmerle CHF, Jung RE. Volume gain and stability of peri-implant tissue following bone and soft tissue augmentation: 1-year results from a prospective cohort study. Clin Oral Impl. Res. 22, 2011; 28–37. doi: 10.1111/j.1600-0501.2010.01987.x. �




The following report summarises the chairperson’s introduction to the The role of provisional restorations in aesthetic implant-supported prosthetic rehabilitations session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

The role of provisional restorations in aesthetic implant-supported prosthetic rehabilitationsOscar GonzalezEAO Congress Scientific Report; (3), 30–31, 2018.

Our aims have evolvedWhile osseointegration is still a basic concern, over the last ten years we have been focused on: the long-term predictability of clinical results; treating complications; and aesthetic outcomes. Indeed, peri-implantitis is becoming increasingly prevalent (Derks et al. 2016), while patients also have growing aesthetic expectations.

Our efforts during the surgical phases of treatment – which may involve preservation, GBR and immediate placement – are directed towards obtaining sufficient volumes of hard and soft peri-implant tissues. At the same time, we are also looking for an effective mucosal seal and a healthy and aesthetic pink soft tissue frame.

Compensatory techniques

Unfortunately neither alveolar preservation (Avila-Ortiz et al. 2013; Horvath et al. 2013) nor GBR (Sicilia et al. 2015) alone let us maintain the natural volume and appearance of tissues. We therefore have to manage two different techniques to compensate for this:

� soft tissue grafting: to improve biology (Linkevicius et al. 2015) and aesthetics (González-Martín et al. 2017), and increase hard and soft tissue stability

� restorative profiles: to create a suitable soft tissue environment. This is where prostheses play a key role

The transgingival area

This area is key for implant aesthetics. The speaker outlined the evolution of management techniques for the transgingival area:

Cervical contouring concept (Bichacho, 1994). This concept was based on obtaining a gentle transition between the shape of implants and teeth, and determining the position of the zenith of the tooth and the gingival margin. The soft tissue is expected to follow the transition shape and be supported by it.

Concave transmucosal abutment (Rompen, 2004). This technique aims to change the emergence profile in order to stabilise the soft tissue. Combined with the former concept, it can achieve a concave subgingival profile. This may not look like a natural tooth from an apical perspective, but as you move further coronally, the shape of the tooth becomes apparent. Once the tissue has matured, modifications of the transition profile can be made by over- or under-contouring the transitional area to manage the position of the tissue margin which can shift under pressure.

Critical and subcritical contour (Su, 2010). The critical contour is the 1mm band under the gingival line; the subcritical contour is apically below this. Depending on which contour is modified, the corresponding position of the soft tissue margin will be reached. The critical contour determines the gingival margin. The subcritical contour – concave, flat or convex – determines the soft tissue volume and therefore its colour and transparency. In this way we can customise the transgingival zone.

References

Avila-Ortiz G, Elangovan S, Kramer KWO, Blanchette D, and Dawson DV. Effect of Alveolar Ridge Preservation after Tooth Extraction. A Systematic Review and Meta-analysis. J Dent Res. 2014 Oct; 93(10): 950–958.

Bichacho N, Landsberg CJ. A modified surgical/prosthetic approach for an optimal single implant-supported crown. Part II. The cervical contouring concept. Pract Periodontics Aesthet Dent. 1994 May;6(4):35–41; quiz 41.

Derks J, Schaller D, Håkansson J, Wennström JL, Tomasi C, Berglundh T. Effectiveness of Implant Therapy Analyzed in a Swedish Population: Prevalence of Peri-implantitis. J Dent Res. 2016 Jan;95(1):43–9. doi: 10.1177/0022034515608832.

Gonzalez-Martin O. Clinical implication of the critical/subcritical contour in the immediate and delayed provisional restoration. Submitted.


Horváth A, Mardas N, Mezzomo LA, Needleman IG, Donos N. Alveolar ridge preservation. A systematic review. Clin Oral Investig. 2013 Mar; 17 (2): 341–63. doi: 10.1007/s00784-012-0758-5. Epub 2012 Jul 20.

Linkevicius T, Puisys A, Steigmann M, Vindasiute E, Linkeviciene L. Influence of Vertical Soft Tissue Thickness on Crestal Bone Changes Around Implants with Platform Switching: A Comparative Clinical Study. Clin Implant Dent Relat Res. 2015 Dec;17(6):1228 36. doi: 10.1111/cid.12222. Epub 2014 Mar 28.

Rompen E, Raepsaet N, Domken O, Touati B, Van Dooren E. Soft tissue stability at the facial aspect of gingivally converging abutments in the esthetic zone: a pilot clinical study. J Prosthet Dent. 2007;97:S119–S125.

Sicilia A, Quirynen M, Fontolliet A, Francisco H, Friedman A, Linkevicius T, Lutz R, Meijer HJ, Rompen E, Rotundo R, Schwarz F, Simion M, Teughels W, Wennerberg A, Zuhr O. Long-term stability of peri-implant tissues after bone or soft tissue augmentation. Effect of zirconia or titanium abutments on peri-implant soft tissues. Summary and consensus statements. The 4th EAO Consensus Conference 2015. Clin Oral Implants Res. 2015 Sep;26 Suppl 11:148–52. doi: 10.1111/clr.12676.

Su H, Gonzalez-Martin O, Weisgold A, Lee E. Considerations of implant abutment and crown contour: critical contour and subcritical contour. Int J Periodontics Restorative Dent. 2010 Aug;30(4):335–43. �




The following report summarises the first paper presented during the The role of provisional restorations in aesthetic implant-supported prosthetic rehabilitations session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Importance of implant position and emergence profile, the role of provisional restorationEva BerroetaEAO Congress Scientific Report; (3), 32–33, 2018.

The importance of planningPreviously, implants were placed where the bone was. Now implants are placed where the prosthesis needs to be. To this end, provisionals and surgical guides are used. Provisionals help modify tissue contours and adjust vertical dimensions. For the definitive prosthesis, ceramics baked onto monolithic zirconia frameworks are often used.

Before surgery, it is crucial to determine where the gingival margins are going to be in order to mimic the natural appearance of teeth. To prevent complications, a proper treatment plan is key (Chee & Jivarj. 2007).

Sometimes it is necessary to modify the soft tissue before implants can be placed (Salama & Salama. 1993). In a multidisciplinary case where orthodontic extrusion was applied, the teeth had to be stabilised at least for 3–4 months. Staged extractions then allowed the soft tissue to be maintained and shaped. Transitional profiles were designed on a plaster model controlling the critical and subcritical contours; polished zirconia abutments were used for the final prostheses to stabilise the soft tissue.

The importance of 3D implant position

A correct 3D implant position is necessary to achieve an aesthetic appearance of the final restoration (Grunder et al. 2005). The speaker recommended using screw-retained prostheses whenever possible. However, if the implant has not been properly positioned, the prosthesis cannot be screwed.

According to the literature, implant malpositioning is reported in less than 1% of cases (Goodacre et al. 2003), although when more stringent criteria to assess positioning are used, this percentage is likely to rise to about the 10% (Chee & Jivarj. 2007). There is a correlation between implant malposition and emergence profiles and aesthetics.

How to treat an implant positioned too buccallyMalposition may lead to a greyish gingival shadow or recession of the mucosal margin (Zabalegui-Andonegui 2002). To resolve this, the crown should

first be changed to a provisional, in order to remove pressure on the mucosa. After several months a CTG should be performed to increase volume and stability, thereby reducing the potential for further recessions (Burkhardt et al. 2008).

If the provisional crown is being cemented, a customised abutment is needed, and it will always have a vestibular over-contoured profile. Thus, over-contouring could lead to excessive apical pressure on the margin, thereby worsening the result.

Another option could be to use angulated abutments (17º and 30º). These abutments can compensate their angulations, but they have a collar measuring 2 or 3mm which protrudes unaesthetically over the soft tissue margin. Besides, it must be noted that they cannot be used in single-unit restorations.

Hence, the speaker recommended dynamic screws to compensate excessive implant angulation. These abutments allow up to 28º of implant inclination. They have no extra vestibular volume, leaving more space in the transgingival area. Additionally, a screwed provisional facilitates the removal of the crown to perform the CTG (Berroeta et al. 2015). After the CTG, the soft tissue can be modelled with the provisional crown. Finally, the definitive prosthesis can be screwed as well.

References

Berroeta E, Zabalegui I, Donovan T, Chee W. Dynamic Abutment: A method of redirecting screw access for implant-supported restorations: Technical details and a clinical report. J Prosthet Dent. 2015 Jun;113(6):516–9. doi: 10.1016/j.prosdent.2014.11.009. Epub 2015 Mar 18.

Burkhardt R, Joss A, Lang NP. Soft tissue dehiscence coverage around endosseous implants: a prospective cohort study. Clin Oral Implants Res. 2008 May;19(5):451–7. doi: 10.1111/j.1600-0501.2007.01497.x. Epub 2008 Mar 26.

Chee W, Jivraj S. Failures in implant dentistry. Br Dent J. 2007 Feb 10;202(3):123–9.

Grunder U, Gracis S, Capelli M. Influence of the 3-D bone-to-implant relationship on esthetics. Int J Periodontics Restorative Dent. 2005 Apr;25(2):113–9.


Salama H, Salama M. The role of orthodontic extrusive remodeling in the enhancement of soft and hard tissue profiles prior to implant placement: a systematic approach to the management of extraction site defects. Int J Periodontics Restorative Dent. 1993 Aug;13(4):312–33.

Zabalegui-Andonegui, I. Influencia de la ubicación de los implantes sobre la restauración definitva. RCOE. 2002, 7(1):47–54. ISSN 1138-123X. �




The following report summarises the second paper presented during the The role of provisional restorations in aesthetic implant-supported prosthetic rehabilitations session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Tissue management in the anterior zone – when, why and how to achieve it in the area around implantsVictor ClavijoEAO Congress Scientific Report; (3), 34–35, 2018.

The treatment concepts we put into practice when rehabilitating teeth using implants should be: based on clinical experience; supported by scientific documentation; and be reproducible or predictable. The speaker presented some multidisciplinary cases with 8 years of follow-up. He emphasised that the position of soft tissue is likely to change over time, especially in patients 25–30 years old. In each case, a decision-making process which took into account the soft tissue as well as the provisionals (which represent 50% of the clinical success) was crucial.

Maintaining the gingival architecture

There are unfavourable and favourable cases; the goal of treatment is to turn the former into the latter. To this end it is advisable to copy the original contour of the tooth and translate this into the prosthesis as closely and accurately as possible. Therefore pre-extraction treatment is very important, and methods for maintaining the gingival contour at the time of extraction and implant placement should be emphasised.

PET: pre-extraction treatment

Before starting treatment, the PET concept makes us ask some questions. What is the ideal timing for extraction? Is it possible to use the tooth being extracted? What is the status of the adjacent tooth? Can it be used to improve the final outcome?

Indeed, there are many possible treatments before extraction. For example, it is possible to submerge the root to avoid severe dehiscence; to place a CTG to improve the initial condition of the soft tissue; to orthodontically extrude the tooth to augment the tissue framework around the future implant; to lengthen the adjacent tooth. All these therapeutic options allow us to improve the peri-implant conditions before undertaking the extraction and placement of the implant itself.

As a rule of thumb, it is critically important to note the proportions and gingival level adjacent tooth in order to determine whether it is suitable to be copied as it is or modified.

After the extractionGood management of the post-extraction phase is a key factor for maintaining the gingival architecture. We must note the shape of the alveolus – oval, triangular, trapezoidal or square.

Prefabricated abutments are not suitable as they do not adapt to the specific form of each alveolus (Korsch & Walther 2015; Hanh 2017, non-indexed). Instead, customised abutments which mimic the transgingival shape of the extracted tooth should be used to improve the long-term stability of the soft tissue.

CSTA: customising socket tissue architectureThe CSTA concept can be performed in four ways: using the patient’s natural tooth; adapting the denture tooth; creating a provisional in the lab; or fabricating it digitally.

Whenever possible, the speaker recommended copying the original tooth. For this technique, the tooth must be included in the pre-extraction impression and then repositioned in the model to be used as a die. The implant is then repositioned in the model and the abutment can be properly adapted to mimic the shape of the extracted tooth.

The horizontal cervical contour is critically important for configuring the soft tissue margin and promoting the mucosal seal (Lops et al. 2008). Vertically, the transgingival zone should have a concave shape to support the soft tissue (Kim et al. 2010).

From the cervical contour, the profile should be progressively concave to stabilise the soft tissue in the vestibular area up to the implant platform which is slightly palatinised (Su et al. 2010).

When provisionalisation has been completed, depending on the evolution of the soft tissue, it may be possible to flatten the cervical contour slightly to allow the soft tissue margin to move coronally if necessary.

If using a digital workflow, the provisional should be prepared before the tooth is extracted. The provisional restoration will be responsible for maintaining the critical horizontal contour.


Take-home messages

The speaker described six steps to follow when utilising this approach:

1. Define the contour of the natural tooth2. Create a continuous area from the horizontal

contour of the natural tooth to the head of the implant

3. Create a buccal and palatal concavity to generate a thick peri-implant tissue

4. Draw a straight line in the interproximal areas (mesial and distal)

5. Reduce the buccal area by 1mm around the horizontal contour

6. Allow a six-month (four minimum) healing/waiting period

References

Hanh J. (non-indexed) 2017. The Clinical Advantages of Custom Abutments: Why Customization is Rendering Stock Abutments Obsolete.

Kim S, Oh KC, Han DH, Heo SJ, Ryu IC, Kwon JH, Han CH. Influence of transmucosal designs of three one-piece implant systems on early tissue responses: a histometric study in beagle dogs. Int J Oral Maxillofac Implants. 2010 Mar–Apr;25(2):309–14.

Korsch M, Walther W. Prefabricated Versus Customized Abutments: A Retrospective Analysis of Loosening of Cement-Retained Fixed Implant-Supported Reconstructions. Int J Prosthodont. 2015 Sep–Oct;28(5):522–6. doi: 10.11607/ijp.4307.

Lops D, Chiapasco M, Rossi A, Bressan E, Romeo E. Incidence of inter-proximal papilla between a tooth and an adjacent immediate implant placed into a fresh extraction socket: 1-year prospective study. Clin Oral Implants Res. 2008 Nov;19(11):1135–40. doi: 10.1111/j.1600-0501.2008.01580.x.

Su H, Gonzalez-Martin O, Weisgold A, Lee E. Considerations of implant abutment and crown contour: critical contour and subcritical contour. Int J Periodontics Restorative Dent. 2010 Aug;30(4):335–43. �




The following report summarises the first paper presented during the Evolution of implant prosthodontics session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Over the past decade, dental prosthodontics have evolved rapidly from analogue to digital workflows. Whether we should switch from one to the other is not yet fully clear. To assess where we are and make this decision, two experts from diverse professional backgrounds were invited.

The first speaker, Stefan Wolfart, works in a university environment (Aachen University) and can treat patients over longer periods of time. Ricardo Mitrani, the second speaker, has a private practice in Mexico, and therefore is under pressure to run his practice and treat patients in shorter timeframes. The session opened with a discussion of how they each handle complex cases.

Is conventional still future oriented?Stefan WolfartEAO Congress Scientific Report; (3), 36, 2018.

Case presentation

When talking about digital vs conventional workflows, both the dentist and the dental technician should be viewed as two connected steps of the one process.

The speaker presented a case involving a complete maxillary rehabilitation. Once validated, a set-up was used to make a radiographic template. Implant placement was guided by a surgical template. Impressions were taken, the maxillomandibular relationship was recorded, and the try-in was performed using a conventional approach.

Next, a digital workflow was adopted. The implant angulations needed to be compensated, and for this the speaker recommended the use of dynamic

abutments to improve the onset of the screws. The framework was designed digitally, so that the available space could be measured and verified in a more precise way.

Once the metal framework had been milled digitally, it was tried-in together with a set-up of the frontal teeth (which had been assembled to test the transition between pink to white aesthetics) to test the fit.

Later, the process returned to an analogue workflow when the metal was veneered with the porcelain in the laboratory. A second try-in was made to re-check and adjust occlusion, and a bite registration was taken before finishing. In total, the speaker used digital methods for only two steps of the process. �




The following report summarises the second paper presented during the Evolution of implant prosthodontics session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

Over the past decade, dental prosthodontics have evolved rapidly from analogue to digital workfl ows. Whether we should switch from one to the other is not yet fully clear. To assess where we are and make this decision, two experts from diverse professional backgrounds were invited.

The fi rst speaker, Stefan Wolfart, works in a university environment (Aachen University) and can treat patients over longer periods of time. Ricardo Mitrani, the second speaker, has a private practice in Mexico, and therefore is under pressure to run his practice and treat patients in shorter timeframes. The session opened with a discussion of how they each handle complex cases.

Is digital the new conventional?Ricardo MitraniEAO Congress Scientifi c Report; (3), 37, 2018.

Case presentation

The speaker described a complex case, where any conventional impressions would lead to accidental tooth extraction. In these cases, it is better to take digital impressions (Figure 1). After having discussed treatment options with the patient, the decision was made to place a fi xed hybrid prosthesis. The high mobility of the teeth also made it very diffi cult to obtain proper interdental records (Figure 2).

The software used to plan treatment had to rely on extra-oral parameters to assess the patient’s face. First, it planned the position of the upper teeth, and then the mandibular teeth, before fi nally planning the implant positions accordingly (Figure 3).

Having completed the planning, surgical guides and provisional prostheses could be fabricated digitally. The guide pins for the surgical template were also used for installing the provisional prosthesis (Figure 4).

Following this approach, the patient was ready for surgery in the second appointment, and the immediate provisional can be placed. The

abutments were fixed to the prosthesis using acrylic, and were then finished in the laboratory to be delivered after a short period of time. The speaker highlighted this workflow requires a very well-coordinated team. �



Figure 1 Figure 3

1 2 3 4

Figure 4Figure 2


The following report summarises the debate between the two speakers during the Evolution of implant prosthodontics session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

DebateStefan Wolfart and Ricardo MitraniEAO Congress Scientific Report; (3), 38–41, 2018.

Why digital? – Stefan Wolfart

In order to move from a proven conventional method to digital procedures, the speaker identified five supporting criteria which he would want to be fulfilled:

� clinical studies must be available � clinical quality improvement � better patient comfort � economic improvement � simplified and faster treatment procedures

There are two steps in the treatment process where conventional methods perform better than digital ones.

Impression-taking: In complex cases involving complete edentulism, the speaker stated that he prefers conventional impression-taking techniques and master cast fabrication methods. A study comparing both procedures in vitro concluded that digital methods had levels of distortion which were four times higher than conventional ones (Amin et al. 2016). Another study of digital impressions (taken using the CEREC Bluecam system) found that the accumulation of errors was significantly higher between single quadrant and full-arch scans (Giménez et al. 2015). Regarding the soft tissue, there have been promising in vitro studies, but transferring their results to in vivo clinical situations should be done with caution, and the mobility of tissues should be taken into account. To conclude, digital scans in full-arch cases are not yet reliable.

Intermaxillary relationship records: In extensive restorations, the limit for ‘going digital’ is the complete loss of occlusal support. In these cases, re-checking occlusion is also a potential source of error in the digital workflow (Zimmermann et al. 2015). Additionally, the benefits of virtually simulating mandibular positions and movements have not yet been scientifically proven. Therefore, for best results the printed articulated models should be mounted in a conventional articulator.

It is also simpler and quicker to take a bite registration and check the smile line and labial support using conventional procedures. At the moment, there are no predictable procedures available for the digital workflow in this step.

Why digital? – Ricardo Mitrani

To answer this question, predictability and efficiency are key. The speaker aimed to illustrate this by describing a case involving a maxillary overdenture where excessively angulated implants were used.

In the first appointment, a digital impression of the implants and of the overdenture was taken. A resin provisional fixed prosthesis which mimicked the shape of the overdenture was generated using CAD/CAM and made up. During the second appointment, the aesthetic parameters were re-checked. The dental proportions could be modified, the pink acrylic placed, and the screw holes closed with composite. After two appointments, the removable prosthesis was switched to a fixed one.

If the patient wears the provisional prosthesis for 4–6 months, the aesthetic, functional performance and hygiene accessibility can be tested in place before a definite prosthesis is made. Thanks to this digital workflow, the speaker’s case could be solved over a few visits, and communication between the clinician and the technician was greatly facilitated.

Are we really more efficient going digital? – Stefan WolfartThe benefits of digital workflows have been demonstrated in cases involving single implants and partial prostheses, especially in posterior quadrants. A digital approach generally has lower production time and associated costs, and fulfils patients’ perceptions of a modern treatment concept (Joda et al. 2017a). Small cases in posterior areas can be performed with a fully digital approach. They can even be finished with monolithic zirconia crowns on customised or pre-fabricated abutments. The only conventional step is the final staining of the crowns.

On the other hand, however, monolithic crowns are not suitable for use in the anterior area. Staining is not sufficient; zirconia needs to be veneered with porcelain, and a working model is required for this. The question now should be: is a conventional model or a digital model preferable?

A comparative study concluded that milled models from digital impressions showed accuracy levels equivalent to gypsum models from conventional impressions. In both types of models, vertical inaccuracies were found (Lee et al. 2015).


In the anterior region, digital procedures have a limited ability to copy the emergence profi le in the soft tissue created by provisionals. The zirconia abutment and the lithium disilicate crown can be made digitally, but the speaker recommended returning to a conventional approach for veneering the crown.

In overdentures, the only evidence for digital workfl ows is that milled CAD/CAM bars are more precise than casted bars made using precious metals.

When and how (digital)? – Ricardo Mitrani

In everyday practice, no fully digital workfl ow exists. We currently use a mixture of analogue/digital approaches. There are several factors which infl uence our decision to follow either a digital or a conventional workfl ow:

� different approaches should be used when treating one jaw or another, or both

� the cause of tooth loss � the morphology and condition of tissues

(Figure 1)

When assessing the condition of tissues, the speaker described the ‘lip-tooth-ridge’ (LTR) classifi cation. LTR classifi cation measures tooth position, lip mobility and support and ridge confi guration (Pollini et al. 2017). Based on this, it is possible to determine which type of prosthesis the patient needs

– removable, fi xed hybrid or implant-supported fi xed prosthesis (Figure 2).

Apart from the aforementioned clinical information, the decision-making process should also take into account the patient’s personal and fi nancial circumstances, as well as their motivation and chief complaint.

Using an example clinical case, the speaker demonstrated how he used an analysis of these diagnostic clinical and personal factors, as well as a facially generated treatment plan, as the starting point. The treatment consisted of:

� extracting all hopeless teeth and implants, and placing two conventional dentures while the tissues could heal

� removing the vestibular fl anges of the upper denture to see if a fi xed implant prosthesis would provide suffi cient lip support

� digitally planning implant positions and performing surgery using a surgical template

� implementing an immediate loading protocol using an analogue conversion protocol

� correcting any errors in the vertical dimension using new CAD/CAM generated provisional restorations

� keeping provisionals in place for six months (or up to a year) to validate function, aesthetic appearance, cleaning accessibility and patient satisfaction

� fabricating and placing the defi nitive prosthesis

Are we really more effi cient going digital? – Stefan WolfartA recent randomised controlled trial compared the digital and the analogue impression-taking methods on models with operators of various levels of experience (Joda et al. 2016a).

Impressions in one quadrant were carried out with intra-oral scanning, whereas full-arch scans were performed using the conventional method. The digital procedure was found to be more effi cient in terms of work-time. However, the preference to choose the digital method was greater for students than for more experienced dentists (76% and 26% respectively) (Joda et al. 2016a). This could be explained by the fact that students, who may be unfamiliar with both systems, tend to choose the quicker procedure, while dentists who are familiar with and confi dent in using conventional procedures are reluctant to switch to a new digital method.

Another study compared monolithic lithium disilicate crowns without physical models with zirconia monolithic veneered crowns on milled models. The reported difference between the two in terms of work-time was low in the clinic, but higher in the laboratory, which translates into a higher cost (estimated at 30% higher) (Joda et al. 2016b).

It is clear that these new technologies are hard to implement for older generations, and that collaboration between specialists is essential. Digital workfl ows encourage us to learn in a continuous way.

How can the workfl ows be integrated? – Stefan WolfartIn a digital workfl ow, material selection is very important. Metal-ceramic restorations are the gold standard, as they are less susceptible to chipping than porcelain veneered zirconia (9% vs nearly 50%) (Pjetursson et al. 2012; Jung et al. 2012). For this reason, all-ceramic restorations should be monolithic, as there is no chipping and they can be perfectly integrated to a digital workfl ow. Here, we must choose between zirconia and lithium disilicate; however, there is not enough evidence supporting aesthetics or longevity of the two, so the question remains open for debate.

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Figure 2


Lithium disilicate monolithic crowns have been shown to present a survival rate of 100% at two-year (Joda et al. 2017b) and fi ve-year (Spies et al. 2017) follow-ups.

However, it is diffi cult to fi nd long-term studies on zirconia monolithic crowns. This is due to the rapid evolution of zirconia as a material, which now has four generations in total. The properties of 2nd generation zirconia and its clinical behaviour have been tested in vitro. The study reported high fl exural strength and resistance to fracture, but lower translucency than lithium disilicate (although light transmission in zirconia is improving) (Flinn et al. 2016).

Regarding possible wear of the antagonist, a two-year follow-up clinical study found no relevant occlusal wear in antagonists, provided that zirconia surfaces were properly polished (Lohbauer & Reich. 2016).

From an aesthetic point of view, there are three options for zirconia:

� zirconia multilayer blocks � staining the surface � veneering zirconia with porcelain

Are we really more effi cient going digital? – Ricardo MitraniThe speaker presented a case involving a CAD/CAM generated, full maxillary provisional restoration. The treatment plan had been made after the intra-oral scans were merged with CBCT data and it had been discussed (online) with the technicians who would be involved in the milling process. When an implant or tooth interferes with the full-arch rehabilitation, the speaker recommended extracting it.

To perform the surgery, a number of surgical guides were used in sequence (Figure 3). The fi rst mimicked the shape of the previously milled provisional to verify the position; the second

guide aided bone reduction. Next, an implant drilling guide was used; after the abutments and temporary cylinders were placed, another guide was used with the exact measurements to position the provisional. Once the provisional was in position, light curing acrylic was injected through holes to bond the cylinders. Once removed, the provisional can be sent back to the laboratory to be re-contoured and fi nished, as can the screw holes and the intaglio (tissue) surface and emergence profi les. This workfl ow has the potential to be really effi cient.

Should we trust digital impressions when performing full-arch restorations? The speaker outlined his preferred workfl ow: to use a conventional open-tray impression technique for the defi nitive prosthesis, which is then fabricated digitally with minimal modifi cations to the provisional.

The speaker summarised by saying that in his experience, and from a positioning standpoint, he has had better results with digital approaches than with analogue ones (Figure 4).

Consequences for daily practice – Stefan WolfartDigital impressions have a protracted learning curve (Ender & Mehl 2013). The individual scanning patterns for different devices have to be learned, and the process for obtaining a detailed copy of a tooth preparation is diffi cult; it is also important that the gingival sulcus is dry. However, the process for scanning implants instead of teeth is easier because preformed scan-bodies can be used. Good communication with the laboratory is mandatory, and they must have the specifi c scan-bodies of the implant being used in their CAD library.

Consequences for daily practice – Ricardo Mitrani

Implants are forever

According to the speaker, the biggest dental lie is the notion that ‘implants are forever’. This is because the intra-oral environment is very hostile, and it must be remembered that implants and implant restorations should not be considered as ‘fl awless or unfailing’, such as other replacements of other body parts. Patients use and abuse teeth and implant prostheses.

We should see ourselves as managing our patients rather than treating them. The key to patient management is communication. If the patient has been previously informed about the possible complications, they will not consider the treatment a total failure if a complication arises. The key is: ‘I told you so’. This is true in analogue, mixed or fully digital workfl ows.

The speaker stated that ‘planned obsolescence’ is one of the main pillars of our society. It means that some products are designed with a limited life-span. This principle, however, does not seem to apply to our fi eld, at least many patients’ views.

Most practitioners are immigrants to the ‘app generation’, and so they are less familiar with the latest digital or technological developments.

Figure 3

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Younger generations are natives, as they have grown up using digital tools.

Regardless of whether we are ready for it, digital technology is becoming increasingly prevalent in our world. It should be viewed as a tool to facilitate our work and our life, rather than hinder it.

References

Amin S, Weber HP, Finkelman M, El Rafie K, Kudara Y, Papaspyridakos P. Digital vs. conventional full-arch implant impressions: a comparative study. Clin Oral Implants Res. 2017 Nov;28(11):1360–1367. doi: 10.1111/clr.12994. Epub 2016 Dec 31.

Ender A & Mehl A. Accuracy of complete-arch dental impressions: a new method of measuring trueness and precision. J Prosthet Dent 2013 Feb;109(2):121–8. doi: 10.1016/S0022-3913(13)60028-1.

Flinn BD, Raigrodski AJ, Mancl LA, Toivola R, Kuykendall T. Influence of aging on flexural strength of translucent zirconia for monolithic restorations. J Prosthet Dent. 2017 Feb;117(2):303–309. doi: 10.1016/j.prosdent.2016.06.010. Epub 2016 Sep 22.

Giménez B, Özcan M, Martínez-Rus F, Pradíes G. Accuracy of a Digital Impression System Based on Active Triangulation Technology With Blue Light for Implants: Effect of Clinically Relevant Parameters. Implant Dent. 2015 Oct;24(5):498-504. doi: 10.1097/ID.0000000000000283.

Joda T, Brägger U. Time-efficiency analysis of the treatment with monolithic implant crowns in a digital workflow: a randomized controlled trial. Clin. Oral Impl. Res. 27, 2016, 1401–1406

Joda T, Ferrari M, Brägger U. Monolithic implant-supported lithium disilicate (LS2) crowns in a complete digital workflow: A prospective clinical trial with a 2-year follow-up. Clin Implant Dent Relat Res. 2017 Jun;19(3):505–511. doi: 10.1111/cid.12472. Epub 2017 Jan 16.

Joda T, Ferrari M, Gallucci GO, Wittneben JG, Brägger U. Digital technology in fixed implant prosthodontics. Periodontol 2000 2017 73:178–192. doi:10.1111/prd.12164

Joda T, Lenherr P, Dedem P, Kovaltschuk I, Bragger U, Zitzmann NU. Time efficiency, difficulty, and operator’s preference comparing digital and conventional implant impressions: a randomized controlled trial. Clin Oral Implants Res. 2017 Oct;28(10):1318–1323. doi: 10.1111/clr.12982. Epub 2016 Sep 5.

Jung RE, Zembic A, Pjetursson BE, Zwahlen M, Thoma DS. Jung RE1, Zembic A, Pjetursson BE, Zwahlen M, Thoma DS. Clin Oral Implants Res. 2012 Oct;23 Suppl 6:2–21. doi: 10.1111/j.1600-0501.2012.02547.x.

Lee SJ, Betensky RA, Gianneschi GE, Gallucci GO. Accuracy of digital versus conventional implant impressions. Clin Oral Implants Res. 2015 Jun;26(6):715–9. doi: 10.1111/clr.12375. Epub 2014 Apr 10.

Lohbauer U, Reich S. Antagonist wear of monolithic zirconia crowns after 2 years. Clin Oral Investig. 2017 May;21(4):1165–1172. doi: 10.1007/s00784-016-1872-6. Epub 2016 Jun 9.

Pjetursson BE, Thoma D, Jung R, Zwahlen M, Zembic A. A systematic review of the survival and complication rates of implant-supported fixed dental prostheses (FDPs) after a mean observation period of at least 5 years. Clin Oral Implants Res. 2012 Oct;23 Suppl 6:22–38. doi: 10.1111/j.1600-0501.2012.02546.x.

Pollini A, Goldberg J, Mitrani R, Morton D. The Lip-Tooth-Ridge Classification: A Guidepost for Edentulous Maxillary Arches. Diagnosis, Risk Assessment, and Implant Treatment Indications. Int J Periodontics Restorative Dent. 2017 Nov/Dec;37(6):835–841. doi: 10.11607/prd.3209.

Spies BC, Pieralli S, Vach K, Kohal RJ. CAD/CAM-fabricated ceramic implant-supported single crowns made from lithium disilicate: Final results of a 5-year prospective cohort study. Clin Implant Dent Relat Res. 2017 Oct;19(5):876–883. doi: 10.1111/cid.12508. Epub 2017 Jun 13.

Zimmermann M, Mehl A, Mörmann WH, Reich S. Intraoral scanning systems – a current overview. Int J Comput Dent. 2015;18(2):101–29. �




The following report summarises the first paper presented during the Insights into surgical approach to the treatment of peri-implantitis session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Peri-implantitis is one of the most important challenges in implant dentistry, yet it still needs to be accurately defined. It is characterised by inflammation of the peri-implant connective tissue which progresses to bone loss around implants, in the same way periodontitis does around teeth. Supported by more than 25 years of research, we can state that bacteria is the origin, and peri-implantitis is an infectious disease. The aim of this session was to shed light on the problems presented by surgical approaches for treating peri-implantitis.

Apically positioned flaps and implantoplastyFrank SchwarzEAO Congress Scientific Report; (3), 42–44, 2018.

The state of the question

There is new pre-clinical and clinical data which we must consider when discussing current treatment approaches for peri-implantitis.

An experimental study in dogs found no significant differences between the outcomes of non-surgical and surgical approaches for treating peri-implantitis with respect to the extension of the inflammatory cell infiltrate (Schwarz et al. 2006).

A recent systematic review and meta-analysis (Schwarz et al. 2015) addressed the question: ‘What is the comparative efficacy of non-surgical and surgical treatments with or without alternative or adjunctive measures on changing signs of inflammation?’ The review made two conclusions:

� non-surgical treatment may benefit from adjunctive or alternative measures

� open debridement does not seem to significantly improve bleeding on probing compared with augmentative treatments (which, in turn, show some improvement)

For the moment, the most effective protocol for decontaminating implant surfaces is unknown. No significant differences in clinical outcomes have been documented (De Waal et al. 2013; De Waal et al. 2015; Papadopoulos et al. 2015). Even the method using cotton pellets with saline performs similar to those using expensive Er:YAG laser devices.

Two landmark studies have demonstrated that implant surface characteristics affect the progression of peri-implantitis, as well as treatment outcomes:

� in a pre-clinical study, machined surfaces behave better than rough surfaces in the canine model (Carcuac et al. 2016)

� a three-year RCT showed better clinical outcomes when systemic antibiotics were added to a conventional surface decontamination with chlorhexidine. The benefits of adjunctive antibiotics were limited to implants with modified surfaces and only to the first year of follow-up (Carcuac et al. 2017)

Implantoplasty

The speaker described one method for smoothing the exposed implant rough surface and threads, which is especially important in light of the above findings. This method uses a sequence of diamond burs with decreasing roughness followed by an Arkansas stone, and has been described in an in vitro study (Ramel et al. 2016). Throughout the entire procedure, the area must be properly cooled with copious irrigation. Titanium debris and particles must also be thoroughly cleaned.

Neither cell vitality nor biocompatibility are impaired by the implantoplasty procedure, and the characteristics of the resulting surface are similar to those of machined non-modified implant surfaces (Thoma et al. 2015; Schwarz et al. 2017). Positive long-term clinical results have also now been reported (Pommer et al. 2016). The surface reduction should not exceed 0.1–0.2mm, otherwise the implant could be weakened and result in biomechanical problems.

Defect configuration

Peri-implantitis generally presents circumferential-type defects with varying intra- and supracrestal areas. More advanced cases can also involve loss of buccal bone. The configuration of the defect heavily influences the treatment which should be performed and the clinical outcome (Schwarz et al. 2010, 2011, 2012, 2013, 2017).

As in bone regeneration, it is hard to rebuild bone around areas where implants are exposed beyond the bony envelope; in these situations, implantoplasty is indicated.

A combined treatment which involves resective surgery and implantoplasty in extra-bony areas, and augmentation procedures in intra-bony areas of the defect which have walls, can offer predictable results. A collagen membrane can also be used to support the biomaterial filler and improve healing in the self-contained areas of the defect.


Remove or maintain?

Long-term results for a combined treatment (which are measured by absence of bleeding on probing and stability of crestal bone levels) are promising even in advanced cases. In a seven-year clinical study, disease resolution was achieved in more than 80% of cases; the results were not influenced by the method of surface decontamination used (Schwarz et al. 2017). In cases involving open debridement, results have to be improved for rough implants (Carcuac et al. 2017); more long-term follow-up is required for some studies (Heitz-Mayfield et al. 2012).

Re-entry surgery was required in five patients because of a lack of keratinised tissue from six months to six and a half years. In these cases, defect fill could be directly assessed and was estimated to occur in 70.63–87.5% of cases (Schwarz et al. 2015). A histological study showed that the documented intrabony filling was new bone; however, it is not clear whether re-osseointegration occurred. In the supracrestal compartment we can just expect new soft tissue adhesion (Schwarz et al. 2011).

Sometimes soft tissue volume grafts were performed simultaneously to minimise post-surgical margin recessions.

In conclusion, we should open our minds to this: why remove an implant if there is evidence that it can be properly maintained for more than seven years?

Conclusions

� surgical therapy of peri-implantitis is effective in the long-term (data from three to seven years)

� clinical outcomes are affected by factors still in study (such as implant surface characteristics or bone defect morphology)

� combined therapy (involving resective/regenerative and implantoplasty) has been proven to be effective at seven years of follow-up

� major clinical indications for implantoplasty are related to advanced (for example, supracrestal) defect sites

References

Carcuac O, Derks J, Abrahamsson I, Wennström JL, Petzold M, Berglundh T. Surgical treatment of peri-implantitis: 3-year results from a randomized controlled clinical trial. J Clin Periodontol. 2017 Dec;44(12):1294–1303. doi: 10.1111/jcpe.12813. Epub 2017 Nov 10.

Carcuac O, Derks J, Charalampakis G, Abrahamsson I, Wennström J, Berglundh T. 2016. Adjunctive systemic and local antimicrobial therapy in the surgical treatment of peri-implantitis: a randomized controlled clinical trial. J Dent Res. 95(1):50–57.

de Waal YC, Raghoebar GM, Huddleston Slater JJ, Meijer HJ, Winkel EG, van Winkelhoff AJ. Implant decontamination during surgical peri-implantitis treatment: a randomized, double-blind, placebo-controlled trial. J Clin Periodontol. 2013 Feb;40(2):186–95. doi: 10.1111/jcpe.12034. Epub 2012 Dec 4.

de Waal YC, Raghoebar GM, Meijer HJ, Winkel EG, van Winkelhoff AJ. Implant decontamination with 2% chlorhexidine during surgical peri-implantitis treatment: a randomized, double-blind, controlled trial. Clin Oral Implants Res. 2015 Sep;26(9):1015–23. doi: 10.1111/clr.12419. Epub 2014 May 26.

Heitz-Mayfield LJ, Salvi GE, Mombelli A, Faddy M, Lang NP; Implant Complication Research Group. Anti-infective surgical therapy of peri-implantitis. A 12-month prospective clinical study. Clin Oral Implants Res. 2012 Feb;23(2):205–10. doi: 10.1111/j.1600-0501.2011.02276.x. Epub 2011 Aug 9.

Papadopoulos CA, Vouros I, Menexes G, Konstantinidis A: The utilization of a diode laser in the surgical treatment of peri-implantitis. A randomized clinical trial, Clin Oral Investig 19(8):1851–1860, 2015.

Pommer B, Haas R, Mailath-Pokorny G, Fürhauser R, Watzek G, Busenlechner D, Müller-Kern M, Kloodt C. Periimplantitis Treatment: Long-Term Comparison of Laser Decontamination and Implantoplasty Surgery. Implant Dent. 2016 Oct;25(5):646–9. doi: 10.1097/ID.0000000000000461.

Ramel CF, Lüssi A, Özcan M, Jung RE, Hämmerle CH, Thoma DS. Surface roughness of dental implants and treatment time using six different implantoplasty procedures. Clin Oral Implants Res. 2016 Jul;27(7):776–81. doi: 10.1111/clr.12682. Epub 2015 Sep 9.

Schwarz F, Bieling K, Venghaus S, Sculean A, Jepsen S, Becker J. Influence of fluorescence-controlled Er:YAG laser radiation, the Vector system and hand instruments on periodontally diseased root surfaces in vivo. J Clin Periodontol. 2006 Mar;33(3):200–8.

Schwarz F, Hegewald A, John G, Sahm N, Becker J. Four-year follow-up of combined surgical therapy of advanced peri-implantitis evaluating two methods of surface decontamination. J Clin Periodontol. 2013 Oct;40(10):962–7. doi: 10.1111/jcpe.12143. Epub 2013 Aug 12.

Schwarz F, John G, Becker J. The influence of implantoplasty on the diameter, chemical surface composition, and biocompatibility of titanium implants. Clin Oral Investig. 2017 Sep;21(7):2355–2361. doi: 10.1007/s00784-016-2030-x. Epub 2016 Dec 24.

Schwarz F, John G, Becker J. Reentry After Combined Surgical Resective and Regenerative Therapy of Advanced Peri-implantitis: A Retrospective Analysis of Five Cases. Int J Periodontics Restorative Dent. 2015 Sep–Oct;35(5):647–53. doi: 10.11607/prd.2320.


Schwarz F, John G, Mainusch S, Sahm N, Becker J. Combined surgical therapy of peri-implantitis evaluating two methods of surface debridement and decontamination. A two-year clinical follow up report. J Clin Periodontol. 2012 Aug;39(8):789–97. doi: 10.1111/j.1600-051X.2012.01867.x. Epub 2012 May 28.

Schwarz F, John G, Schmucker A, Sahm N, Becker J. Combined surgical therapy of advanced peri-implantitis evaluating two methods of surface decontamination: a 7-year follow-up observation. J Clin Periodontol. 2017 Mar;44(3):337–342. doi: 10.1111/jcpe.12648. Epub 2017 Jan 19.

Schwarz F, Mihatovic I, Ferrari D, Wieland M, Becker J. Influence of frequent clinical probing during the healing phase on healthy peri-implant soft tissue formed at different titanium implant surfaces: a histomorphometrical study in dogs. J Clin Periodontol. 2010 Jun;37(6):551–62. doi: 10.1111/j.1600-051X.2010.01568.x.

Schwarz F, Schmucker A, and Becker J. Efficacy of alternative or adjunctive measures to conventional treatment of peri-implant mucositis and peri-implantitis: a systematic review and meta-analysis. Int J Implant Dent. 2015 Dec; 1(1): 22.

Schwarz F, Sahm N, Iglhaut G, Becker J. Impact of the method of surface debridement and decontamination on the clinical outcome following combined surgical therapy of peri-implantitis: a randomized controlled clinical study. J Clin Periodontol. 2011 Mar;38(3):276–84. doi: 10.1111/j.1600-051X.2010.01690.x. Epub 2011 Jan 11.

Thoma DS, Kruse A, Ghayor C, Jung R, Weber FE. Bone augmentation using a synthetic hydroxyapatite/silica oxide-based and a xenogenic hydroxyapatite-based bone substitute materials with and without recombinant human bone morphogenetic protein-2. Clin. Oral Impl. Res. 26, 2015, 592–598 doi: 10.1111/clr.12469. �




The following report summarises the second paper presented during the Insights into surgical approach to the treatment of peri-implantitis session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Peri-implantitis is one of the most important challenges in implant dentistry, yet it still needs to be accurately defined. It is characterised by inflammation of the peri-implant connective tissue which progresses to bone loss around implants, in the same way periodontitis does around teeth. Supported by more than 25 years of research, we can state that bacteria is the origin, and peri-implantitis is an infectious disease. The aim of this session was to shed light on the problems presented by surgical approaches for treating peri-implantitis.

Flap design based on peri-implant defect characteristicsAlberto Ortiz-VigónEAO Congress Scientific Report; (3), 45–47, 2018.

The speaker began by presenting a clinical case which involved an unaesthetic soft tissue dehiscence and very poor patient satisfaction. Although the criteria for peri-implant health had been met (PPD ≦ 5mm, no BoP and no bone loss > 5mm) (Sanz et al. 2012), the dehiscence appeared after the initial six-month healing period. It is possible that this was caused by an inadequate surgical approach.

When treating patients with similar problems, lesions must be resolved; bone levels must be stabilised; and the patient’s demands about comfort and aesthetic must also be met. These treatment areas can be categorised according to the ‘BMP concept’ – bone, mucosa, patient.

In the first step (bone), the treatment approach should be based on the classification of defect morphologies defined by the speaker, Professor Schwarz and coworkers (Schwarz et al. 2010) (Figure 1).

Bone defects

In cases involving class 2 or supracrestal defects, our approach should be resective: remove the granulation tissue; decontaminate the exposed implant surface; recontour the bone; polish the new transmucosal area; and apically reposition the flap (Figures 2–4).

As the previous speaker had mentioned, a recent in vitro study confirmed that implantoplasty procedures leave implant surfaces similar to

machined surfaces, while the implant strength remains unchanged (Costa et al. 2017). Regardless, however, biomechanical concerns surrounding narrow diameter implants with internal connections persist, as according to clinical observations they seem to be more prone to fracture after implantoplasty. Demand is growing for devices which facilitate implant decontamination

Figure 1

Figure 2

Figure 3

Figure 4


but do not remove too much of the titanium surface (Figure 5).

By contrast, in cases involving class 1 or intra-bony defects, our approach should be to reconstruct: raise a full thickness flap; decontaminate the implant surface; fill the intra-bony compartments with xenograft; and cover with a collagen membrane (Figures 6–7).

Whether a membrane is used or not does not seem to influence bone levels. However, analysing healing complications in a five-year follow-up period, the following conclusion can be made: when using a membrane, 44% of patients had exposures and 79% showed crater-like lesions in the soft tissue margin (Roos-Jansåker et al. 2007).

Mucosa

Although the evidence is limited, we can presume that the amount of keratinised tissue around implants can influence successful long-term maintenance of peri-implant stability. A systematic review stated that it has no effect on well-maintained patients, but it seems to be significant in non-maintained patients, and recessions are more pronounced when sufficient keratinised mucosa is lacking (Wennström & Derks.

2012). The practical conclusion may be that grafting procedures should be considered individually.

A recent clinical study found more plaque accumulation, discomfort when brushing, and peri-implant inflammation when a band of less than 2mm of keratinised tissue was present (Souza et al. 2016). In these situations, the speaker recommended soft tissue augmentation.

A clinical study comparing free gingival flaps with collagen matrices in peri-implantitis patients is currently being carried out, but results are not ready yet (Solonko et al. 2018).

Patient

Patient-reported outcomes measures (PROMs) were one of the recommendations of the 8th European Workshop on Periodontology. This highlights the fact that patients have a subjective perception of treatment, and this has to be included in criteria for success (Lang et al. 2012).

A recent study concluded that patients can have unrealistically high expectations of implant therapy. This can make dentist/patient relationships difficult to manage in cases involving peri-implantitis (Abrahamsson et al. 2016). It is currently clear that treatment decisions must take into account the expectations, circumstances and compliance of the individual patient.

To illustrate this, the speaker presented a case involving a malpositioned implant in the aesthetic area which had developed a supracrestal defect. The treatment approach which was selected involved removing the implant and performing soft tissue augmentation. To treat the residual defect in the adjacent tooth, a modified flap was raised to allow regeneration of the defect (Figure 8) and the flap was then coronally advanced.

Take home messages (Figure 9)

� a resective approach for treating class 2 defects in non-aesthetic areas is recommended

� a reconstructive approach is recommended for class 1 intra-bony defects, as it may achieve better results

� the decision to perform soft tissue augmentation should be made based on individual cases

� in aesthetic areas, a modified flap technique can be used to minimise recessions

Figure 5

Figure 6

Figure 7

Figure 8


When planning treatment, the decision-making process for raising a flap should be based on a reverse BMP concept: PMB (patient-mucosa-bone). The factors which should be considered at each stage are:

� patient: aesthetic demands and implant position � mucosa: hygiene access and keratinised tissue � bone: defect morphology and surface treatment

References

Abrahamsson K, JL Wennström, Berglundh T, Abrahamsson I. Altered Expectations on Dental Implant Therapy; Views of Patients Referred for Treatment of Peri-Implantitis. Clin Oral Implants Res, 28 (4), 437–442.

Costa-Berenguer X, García-García M, Sánchez-Torres A, Sanz-Alonso M, Figueiredo R, Valmaseda-Castellón E. Effect of implantoplasty on fracture resistance and surface roughness of standard diameter dental implants. Clin Oral Impl Res. 2018;29:46–54. https://doi.org/10.1111/clr.13037

Lang N, Zitzmann N, Ortiz-Vigón A. 2012. Clinical research in implant dentistry: Evaluation of implant-supported restorations, aesthetic and patient-reported outcomes. Journal of Clinical Periodontology. 39 Suppl 12. 133–8. 10.1111/j.1600-051X.2011.01842.x.

Roos-Jansåker A-M, Persson GR, Lindahl C, Renvert S. Surgical treatment of peri-implantitis using a bone substitute with or without a resorbable membrane: a 5-year follow-up. J Clin Periodontol 2014; 41: 1108–1114. 10.1111/jcpe.12308.

Sanz, M., Chapple, I. L. and on behalf of Working Group 4 of the VIII European Workshop on Periodontology* (2012), Clinical research on peri-implant diseases: consensus report of Working Group 4. J Clin Periodontol, 39: 202–206. doi:10.1111/j.1600-051X.2011.01837.x

Schwarz, F., Sahm, N., Schwarz, K. and Becker, J. Impact of defect configuration on the clinical outcome following surgical regenerative therapy of peri-implantitis. Journal of Clinical Periodontology, 2010; 37: 449–455. doi:10.1111/j.1600-051X.2010.01540.x

Solonko et al. Patient perception and clinical efficacy of collagen matrix versus free gingival graft in the treatment of peri-implantitis: Multicenter randomized clinical trial. In preparation, 2018.

Souza AB, Tormena M, Matarazzo F, Araújo MG. The influence of peri-implant keratinized mucosa on brushing discomfort and peri-implant tissue health. Clin. Oral Impl. Res. 27, 2016, 650–655

Wennström J & Derks J. Is there a need for keratinized mucosa around implants to maintain health and tissue stability? Clin Oral Implants Res. 2012 Oct;23 Suppl 6:136–46. doi: 10.1111/j.1600-0501.2012.02540.x. �



Figure 9


The following report summarises the chairperson’s introduction to the Avoid nightmares when restoring the edentulous upper jaw. Is the material the key factor? session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Avoid nightmares when restoring the edentulous upper jaw. Is the material the key factor?Christoph HämmerleEAO Congress Scientific Report; (3), 48, 2018.

Inconclusive scientific evidenceThe session chair described the materials currently available for implant prostheses: metal-resin, metal-ceramic, ceramic-ceramic, full ceramic. In the near future, full hybrid (hybrid ceramic or hybrid materials) may become available.

After reviewing the most relevant papers on the subject, the chairperson concluded that there is currently insufficient scientific evidence to support the use of one particular material in full-arch restorations – neither the conventional metal-resin (Fischer & Stenberg. 2013) nor the metal-ceramic (Lambert et al. 2009; Papaspyridakos et al. 2012), nor the more recent monolithic zirconia restorations (Abdulmajeed et al. 2016; Bidra et al. 2017). The field is therefore open to discussion.

References

Abdulmajeed AA, Lim KG, Närhi TO, Cooper LF. Complete-arch implant-supported monolithic zirconia fixed dental prostheses: A systematic review. J Prosthet Dent, 2016;115(6):672–7.

Bidra AS, Rungruanganunt P, Gauthier M. Clinical outcomes of full arch fixed implant-supported zirconia prostheses: A systematic review. Eur J Oral Implantol. 2017;10 Suppl 1:35–45. PMID: 28944367.

Fischer K, Stenberg T. Prospective 10-Year Cohort Study Based on a Randomized, Controlled Trial (RCT) on Implant-Supported Full-Arch Maxillary Prostheses. Part II: Prosthetic Outcomes and Maintenance. Clinical Implant Dentistry and Related Research, 2013; 15: 498–508. doi:10.1111/j.1708-8208.2011.00383.xLambert et al. J Periodontol 2009.

Lambert, FE, Weber HP, Susarla SM, Belser UC, Gallucci GO. Descriptive analysis of implant and prosthodontic survival rates with fixed implant–supported rehabilitations in the edentulous maxilla. J Periodontol, 2009;80(8):1220–30. doi: 10.1902/jop.2009.090109.

Papaspyridakos P, Chen CJ, Chuang SK, Weber HP, Gallucci GO. A systematic review of biologic and technical complications with fixed implant rehabilitations for edentulous patients. Int J Oral Maxillofac Implants. 2012 Jan–Feb;27(1):102–10. �




The following report summarises the first paper presented during the Avoid nightmares when restoring the edentulous upper jaw. Is the material the key factor? session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Full arch ceramo-metal restorationsGaetano CalesiniEAO Congress Scientific Report; (3), 49–50, 2018.

The genesis of nightmares

Implant positions in the upper arch can be compromised by loss of bone volume caused by post-extraction resorption. This hostile environment can be transformed into a more favourable one with surgery and prosthetics. The standard surgical approach for this condition is GBR.

Morphogenic bone splitting

The speaker recommended an alternative augmentation procedure: morphogenic bone splitting. This surgical technique has been shown to present the highest implant survival and success rates among current augmentation procedures, as well as the lowest levels of long -term bone resorption (Chiapasco et al. 2006) (Figure 1).

The original technique (‘split crest’) was developed by Agostino Scipioni and Gaetano Calesini in 1984. The modern approach (‘morphogenic tissue management approach’), involves expanding the whole osseo-muco-gingival complex, allowing a dramatic change of the residual ridge in three planes (Scipioni et al. 2008) (Figure 2). Once a vertical incision has been made in the osseo-muco-gingival complex, the implant is placed, helping to support the buccally displaced complex (Figure 3).

It is important to prevent fractures in the basal bone. The tissues will heal by second intention, without biomaterials or membranes. This procedure ensures an optimal implant position for rehabilitation. It should also be noted that healing by second intention leads to buccal soft tissue augmentation. The technique compensates for lost tissue volume without the need for regenerative techniques, improving the cleansability and aesthetics of future prostheses.

According to the speaker, this technique often presents the simplest, fastest and most economical option for patients. Healing by second intention converts the healing process into a regenerative one. Three phases can be distinguished in the procedure:

1. Surgery and implant placement, to change and maintain the morphology of the osseo-muco-gingival complex

2. Promotion of the new peri-implant morphology (the gingival margin) through the connection of the prosthesis

3. Redefinition of the shape of the anatomy through patient’s masticatory function

The morphogenic tissue management approach can consistently offer improved 3D positions of implants both in single-tooth and full-arch restorations. The speaker stated that in the anterior area, horizontal volume is augmented by 4–6mm; in the premolar area by 8–12mm; and by 13–15mm in the posterior area.

Not only is masticatory function improved (without the need for cantilevers), but phonetics and labial support as well. The approach also helps in achieving 3D coherence between implant and crown diameters and occlusion between the two arches (Figure 4).

Figure 1

Figure 2

Figure 3


Is the material an issue?

Material selection is usually determined by a patient’s biomechanical conditions, such as type of occlusion, or the presence of heavy function or parafunction. But one thing which is more important than what material is used is: whether there is 3D coherence between the implant positions and the final functional position of the prostheses. Malpositioned implants generate an angulated implant/prosthesis interface, causing technical complications and higher failure rates.

In conclusion, the choice of material in full-arch rehabilitations is less important than correct 3D positioning of the implants, after the anatomical environment has been transformed from hostile to favourable. Besides the retention and resistance of the prosthesis, implants serve to maintain the long-term architecture of the osseo-muco- gingival complex.

References

Chiapasco M, Zaniboni M, Boisco M. Augmentation procedures for the rehabilitation of deficient edentulous ridges with oral implants. Clin Oral Implants Res. 2006 Oct;17 Suppl 2:136–59.

Scipioni A, CalesiniG, Micarelli C, Coppè S, Scipioni L. Morphogenic bone splitting: Description of an original technique and its application in esthetically significant areas. Int J Prosthodont 2008;21:389–97. �



Figure 4.1

Figure 4.2


The following report summarises the second paper presented during the Avoid nightmares when restoring the edentulous upper jaw. Is the material the key factor? session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Full arch zirconia rehabilitationsWael AttEAO Congress Scientific Report; (3), 51, 2018.

Materials and digital revolution

By merging different forms of data (.stl, .dcm, .jpg and .obj files) clinicians can create complete treatment plans digitally, and labs can fabricate prostheses before treatment begins. Although this workflow reduces time and cost, especially in cases involving immediate loading, there are still things to improve.

A revolution in materials has also taken place. A number of new materials have appeared, such as: resin nanoceramics, glass-matrix ceramics, or zirconia ceramics (Gracis et al. 2015).

Clinical steps for fabricating full-arch zirconia rehabilitationsThe speaker presented a case involving a full conventional restoration on residual hopeless natural abutments. First, the treatment planning process was described, from virtual implant placement followed by guided surgery and immediate provisionalisation. After a healing period of 3–6 months, a prototype of the definitive prosthesis was fabricated in resin or PMA. The patient wore this prosthesis for several weeks so it could be adjusted as required. When both patient and clinician were satisfied with it, the prosthesis was recreated in zirconia.

What we know about these rehabilitations

There are three types of zirconia available:

� traditional � partially-translucent � translucent

As the translucency increases, stiffness decreases. Thus, more translucent zirconia is not recommended for full-arch restorations. The main problem with this type of restoration is chipping, which occurs often. Chipping is not one of the parameters influencing survival of the prosthesis. For this reason, prosthetic survival is not a reliable tool for evaluating the outcome of restorations, and should not be used to formulate clinical recommendations (Bagegni et al. Submitted). A recent systematic review confirmed that full-arch prostheses on

zirconia veneered with ceramic laminates have a high tendency to chip; the review concluded that only the pink gingival area is suitable for veneering (Bidra et al. 2017).

On the other hand, the wear of antagonist teeth must also be considered. Neither the type of materials facing the zirconia nor its microstructure shows a significant effect in this regard. The surface roughness of zirconia has the greatest effect on its own wear and on the wear of antagonist teeth (Aldegheishem et al. 2015). Post-sintering surface modifications of monolithic zirconia should be avoided.

The speaker then summarised the evidence available on the clinical performance of full-arch zirconia restorations.

Avoiding nightmares

The speaker emphasised the importance of using a prosthetic prototype (made using CAD/CAM) from the initial planning stages, so as to prevent the need for occlusal adjustments in the definite prosthesis later. Grinding the zirconia generates roughness which in turn leads to wearing of the antagonist teeth.

Although they are not supported by a strong scientific evidence-base, the speaker listed a number of clinical recommendations for avoiding nightmares.

References

Aldegheishem A, Alfaer A, Brezavšček M, Vach K, Eliades G, Att W. Wear behavior of zirconia substrates against different antagonist materials. Int J Esthet Dent 2015;10(3):468–85. PMID:26171448.

Bagegni et al. J Prosthodont Res (submitted)Bidra AS, Rungruanganunt P, Gauthier M. Clinical

Outcomes of Full Arch Fixed Implant-Supported Zirconia Prostheses: A Systematic Review. Eur J Oral Implantol 10 Suppl 1, 35–45. 2017

Gracis, S, Thompson, VP, Ferencz, JL, Silva, NR, Bonfante, EA. A new classification system for all-ceramic and ceramic-like restorative materials. Int J Prosthodont. 2015; 28(3):227–235. �




The following report summarises the fi rst paper presented during the How to choose the proper connection and abutment session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

External connections and no abutmentsJoão CaramêsEAO Congress Scientifi c Report; (3), 52–53, 2018.

For decades, most implants featured external hexagon connections, according to the protocol introduced by Brånemark in 1977. These implants demonstrated predictable long-term success rates. But after over 50 years, the question we currently face is: ‘Do we have better implant connections now?’

First, we must assess what has changed and how. Many concepts have developed over the years:

� macrogeometry � microtextures � neck designs � platform switching � internal connection confi gurations � abutment materials and designs � the ‘one abutment, one time’ concept

Internal connections are now generally considered superior to external connections. However, this expectation, and the corresponding decision-making process, should be supported by a careful analysis of the evidence. This analysis must be based on scientifi c evidence, clinical experience and patients’ needs.

The speaker specifi ed that in his presentation he would only include systematic reviews, randomised clinical trials (RCTs) and human clinical trials. Animal trials, in vitro studies and fi nite element analyses would be excluded. He also outlined a number of clinically relevant factors which would be discussed in relation to the biological and prosthodontic considerations (Figure 1).

Biological considerations

It seems that the type of implant connection does not infl uence early failures. A fi ve-year retrospective study on 4,126 implants with two-year post-loading follow-ups found no difference between the connections (Caramês. 2017, preliminary results).

Marginal bone loss is an essential parameter for measuring implant success. A systematic review comparing the two types of connections reported lower levels of marginal bone loss for internal connections (Medeiros et al. 2016), but the results mainly pertained to platform switching. The authors of the review concluded that platform switching may be more important for preserving marginal bone than the connection type itself. Furthermore, another RCT comparing the connections of identical implants found no signifi cant differences between the two after fi ve years of follow-up (Esposito et al. 2016). A one-year split-mouth RCT found that internal connections performed better, but the sample size was too small (Pessoa et al. 2016). From this, we may conclude that clinicians can choose connection types based on their personal preference.

Regarding soft tissue responses, a systematic review compared external and internal connections and concluded that although

complications were more frequently associated with external connections, there was no statistically signifi cant difference between connection types for biological or aesthetic complications (Zembic et al. 2014). Emergence profi les seemed to infl uence soft tissue aesthetics more than the connection type did (Figures 2–3).

Figure 1

CLINICALLY RELEVANT FACTORS

EARLY FAILURE

MARGINAL BONE LOSS

LATE FAILURE

SOFT TISSUE RESPONSE

IMPRESSION ACCURACY

PROSTHODONTIC COMPLICATIONS

Figure 2

Figure 3

EXTERNALmatched platform

INTERNALswitching platform


The speaker stated that no statistical differences between late failure rates were found in inter-group comparisons carried out by him and his team (Caramês, J. EAO 2017, preliminary results), or in a systematic review of 1,877 patients and 2,999 implants (Zembic et al. 2014).

Prosthodontic considerations (Figure 4)

A study which surveyed dentists in Japan found that they considered internal connections in single implants easier to manage. This is because the abutment insertion procedure is automatically guided in internal connections, and the seating of internal connections is easier (Hagiwara & Carr. 2015).

In multiple and angulated implants, however, impression accuracy is much more demanding, especially with internal connections (Gotfredsen et al. 2012). The solution for this is to place angulated abutments which can balance the parallel path of insertion and convert internal connections into external connections.

An RCT assessing bone and soft tissue response around implants with or without abutments concluded that the use of machined abutments may benefi t results in terms of marginal bone stability over time (Gothberg et al. 2015).

Regarding prosthodontic complications, a systematic review found that abutment fractures and screw fractures had similar rates of occurrence; however, screw loosening occurred signifi cantly more frequently in the external connection (with both metal and zirconia abutments) (Gracis et al. 2012).

Take-home messages: Figures 5–6.

References

de Medeiros RA, Pellizzer EP, Vechiato Filho AJ, Dos Santos DM, Freitas da Silva EV, Goiato MC. Evaluation of Marginal Bone Loss of Dental Implants With Internal or External Connections and Its Association With Other Variables: A Systematic Review. J Prosthet Dent 116 (4), 501–506.e5. 2016 Jul 14.

Esposito M, Zucchelli G, Barausse C, Pistilli R, Trullenque-Eriksson A, Felice P. Four mm-long versus longer implants in augmented bone in atrophic posterior jaws: 4-month post-loading results from a multicentre randomised controlled trial. Eur J Oral Implantol. 2016;9(4):393–409.

Gotfredsen K , Wiskott A. Consensus report reconstructions on implants. The Third EAO Consensus Conference 2012. Clin. Oral Impl. Res. 23(Suppl. 6), 2012, 238–241 10.1111/j.1600-0501.2012.02549.x

Göthberg C, André U, Gröndahl K, Thomsen P, Slotte C. Bone Response and Soft Tissue Changes Around Implants With/Without Abutments Supporting Fixed Partial Dentures: Results From a 3-Year, Prospective, Randomized, Controlled Study. Clinical implant dentistry and related research. 2016;18(2):309–322. doi:10.1111/cid.12315.

Gracis S, Michalakis K, Vigolo P, Vult von Steyern P, Zwahlen M, Sailer I. Internal vs. external connections for abutments/reconstructions: a systematic review. Clin Oral Implants Res. 2012;23 Suppl 6:202-216.

Hagiwara Y, Carr AB. External versus internal abutment connection implants: a survey of opinions and decision making among experienced implant dentists in Japan. Odontology. 2015;103(1):75–83. doi:10.1007/s10266-013-0141-2.

Pessoa RS, Sousa RM, Pereira LM, Neves FD, Bezerra FJB, Jaecques SVN, Sloten JV, Quirynen M, Teughels W, Rubens Spin-Neto R. Bone Remodeling Around Implants With External Hexagon and Morse-Taper Connections: A Randomized, Controlled, Split-Mouth, Clinical Trial. Clin Implant Dent Relat Res 19 (1), 97–110. 2016 Jun 29.

Zembic A, Kim S, Zwahlen M, Kelly JR. Systematic review of the survival rate and incidence of biologic, technical, and esthetic complications of single implant abutments supporting fixed prostheses. Int J Oral Maxillofac Implants. 2014;29 Suppl:99–116. �



Figure 4

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BIOLOGICAL considerations PROSTHODONTIC considerations

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SOFT TISSUEHARD TISSUE

SOFT

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SUE

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Figure 5

TAKE HOME MESSAGE

External Hexagon?

Is still an option.

Internal connection expectations…

…don’t seem to be reflected at the highest levels of scientific evidence.

No Abutment?

Better use it.

Figure 6

TAKE HOME MESSAGE

Internal Connection Biological Advantage?

Seems uncertain.

Internal Connection Mechanical Advantage?

Appears evident.

There are multiple factors capable of masking a true effect of the implant connection type.


The following report summarises the second paper presented during the How to choose the proper connection and abutment session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Internal connections and abutmentsXavier VelaEAO Congress Scientific Report; (3), 54–56, 2018.

This presentation compared external and internal hexagon connections from a clinician’s point of view, in order to identify and prevent clinical problems.

Biologic width

Supracrestal connective tissue is responsible for maintaining soft tissue architecture and can act as an effective seal for protecting the underlying bone. For decades, implant designs have imitated tooth morphology. But in spite of this, tissues around implants still react differently than they do around natural teeth. Marginal bone is lost and epithelial downgrowth deepens the sulcus, encouraging the connective tissue to stabilise in an intracrestal position.

Eight weeks after the implant is exposed to the oral cavity, communication between the internal and external environments is established, and the body must form a barrier to close what is essentially an open wound (Berglundh et al. 2007; Hermann et al. 1997; Ericsson et al. 1996). This process forms the biologic width which produces an apical migration of the tissues.

The process of the histo-morphogenesis of the biologic width can be divided into four steps (Cochran et al. 2008; Terheyden et al. 2012):

� haemostasis: within minutes of implant placement a blood clot forms, which will work as the provisional matrix

� inflammation: over the next few days, the blood clot is infiltrated by leucocytes and the immune response leads to unavoidable tissue destruction

� proliferation: in the weeks after, the tissue undergoes new vascularisation, and fibroblasts migrate to the abutment and begin producing collagen fibres

� remodelling: in the following months, bone continues to be lost at a very low rate

Collagen fibres cannot attach to the abutment surface, but will shrink around it to close the cicatricial ring as much as possible. Tissue healing around abutments is second intention healing, and the main feature of this kind of healing is contraction. In the first two weeks of the proliferation stage, 70% of the fibroblasts become myofibroblasts which can contract actively. If a

divergent abutment is placed, the shrunken soft tissue collar will move apically.

The circular fibres of the connective tissue require mechanical support; because they cannot attach to the abutment, they need to be supported by the first thread of the implant or even the same platform. When platform switching has been carried out, it can stabilise the connective fibres and stop apical migration. This is a consistent clinical observation and has been demonstrated in an experimental study in the dog model (Rodríguez et al. 2012).

The second problem is the repeated disconnection and reconnection of the abutment as part of the prosthetic protocol. An experimental study found that repeated abutment dis- and re-connection breaks the mucosal seal and leads to additional apical migration of the tissues, as the healing process has to be started each time (Abrahamsson et al. 1997; Abrahamsson et al. 2003; Rodriguez et al. 2013).

As a result, peri-implant tissue collapse and soft tissue recessions of about 1mm should be expected in the first year post-loading (Grunder, U. 2000; Small & Tarnow. 2000).

Biologic width and platform switching

The speaker recommended that we do not try to imitate the shape of the tooth, but rather its function. By creating extra space for the supracrestal connective tissue, apical migration can be minimised, as can the subsequent crestal bone loss during the formation of the biologic width. In this way, a supracrestal position of the fibre collar and short epithelial sulcus can be achieved.

The final abutment must be screwed when the implant is uncovered and should not be disconnected. If a provisional is placed, space is formed to stabilise and protect the blood clot. This is known as the so-called ‘chamber concept’ (Degidi et al. 2013).

There are three characteristics in this technique which offer advantages during the proliferation healing phase:

1. Platform switching. The discrepancy between the diameters of the implant and abutment is used as a mechanical stop for forming collagen fibres (Rodríguez et al. 2012)


2. Micro-threads at the bottom of the abutment. Micro-grooved surfaces take advantage of the

‘contact guidance’, a tendency for fibroblasts to grow in linear directions. This feature also increases fibroblast adhesion and activation in order to produce more collagen (Brunette et al. 1988; Doyle et al. 2009; Martí et al. 2012)

3. Convergent or conical abutments. This shape guides tissue shrinkage towards the narrower diameter, thus stabilising the tissue in a coronal position (Rodriguez et al. 2016; Rodriguez et al. 2017)

It is clear that if the bone level is higher and a collar of circular fibres is formed around the abutment in a supracrestal position, the collagen fibres attached to the surrounding periosteum will inhibit further bone loss during the remodelling stage (Warren et al. 2002; Urdaneta et al. 2014).

These abutments do not have margins, and so do not have a ‘finish line’ because they are never disconnected. So the prostheses have knife-edge margins which can be easily adapted to the final clinical situation.

Advantages of internal connections

Multiple studies have shown that internal connections have better performances. Six advantages have been identified:

1. Reduced micro-movements2. Better biomechanical behaviour3. Even load distribution4. Less screw loosening5. Less micro-leakage6. Lower levels of marginal bone loss

References

Abrahamsson I, Berglundh T, Lindhe J. The mucosal barrier following abutment dis/reconnection. An experimental study in dogs. J Clin Periodontol. 1997 Aug;24(8):568–72.

Abrahamsson I, Berglundh T, Sekino S, Lindhe J. Tissue reactions to abutment shift: an experimental study in dogs. Clin Implant Dent Relat Res. 2003;5(2):82–8.

Berglundh T, Abrahamsson I, Welander M, Lang NP, Lindhe J. Morphogenesis of the peri-implant mucosa: an experimental study in dogs. Clin Oral Implants Res. 2007 Feb;18(1):1–8.

Brunette DM. The effects of implant surface topography on the behavior of cells. Int J Oral Maxillofac Implants. 1988 Winter;3(4):231–46.

Cochran DL. Inflammation and bone loss in periodontal disease. J Periodontol. 2008 Aug;79(8 Suppl):1569–76. doi: 10.1902/jop.2008.080233.

Degidi M, Daprile G, Nardi D, Piattelli A. Immediate provisionalization of implants placed in fresh extraction sockets using a definitive abutment: the chamber concept. Int J Perio Rest Dent. 2013 Sep–Oct;33(5):559–65. doi: 10.11607/prd.1795.

Doyle AD, Wang FW, Matsumoto K, Yamada KM. One-dimensional topography underlies three-dimensional fibrillar cell migration. J Cell Biol. 2009 Feb 23;184(4):481–90.

Ericsson I, Persson LG, Berglundh T, Edlund T, Lindhe J. The effect of antimicrobial therapy on periimplantitis lesions. An experimental study in the dog. Clin Oral Implants Res. 1996 Dec;7(4):320–8.

Grunder, U. Stability of the mucosal topography around single-tooth implants and adjacent teeth: 1-year results. Int J Periodontics Restorative Dent. 2000 Feb;20(1):11–7.

Guillem-Marti J, Delgado L, Godoy-Gallardo M, Pegueroles M, Herrero M, Gil FJ. Fibroblast adhesion and activation onto micro-machined titanium surfaces. Clin Oral Implants Res. 2013 Jul;24(7):770–80. doi: 10.1111/j.1600-0501.2012.02451.x. Epub 2012 Mar 28.

Hermann JS1, Cochran DL, Nummikoski PV, Buser D. Crestal bone changes around titanium implants. A radiographic evaluation of unloaded nonsubmerged and submerged implants in the canine mandible. J Periodontol. 1997 Nov;68(11):1117–30.

Rodríguez X, Navajas A, Vela X, Fortuño A, Jimenez J, Nevins M. Arrangement of Peri-implant Connective Tissue Fibers Around Platform-Switching Implants with Conical Abutments and Its Relationship to the Underlying Bone: A Human Histologic Study. Int J Perio Rest Dent. 2016 Jul–Aug;36(4):533–40. doi: 10.11607/prd.2580.

Rodríguez X, Vela X, Calvo-Guirado JL, Nart J, Stappert CF. Effect of platform switching on collagen fiber orientation and bone resorption around dental implants: a preliminary histologic animal study. Int J Oral Maxillofac Implants. 2012 Sep–Oct;27(5):1116–22.

Rodríguez X, Vela X, Méndez V, Segalà M, Calvo-Guirado JL, Tarnow DP. The effect of abutment dis/reconnections on peri-implant bone resorption: a radiologic study of platform-switched and non-platform-switched implants placed in animals. Clin Oral Implants Res. 2013 Mar;24(3):305–11. doi: 10.1111/j.1600-0501.2011.02317.x. Epub 2011 Oct 3.

Rodriguez X, Vela X, Segalá M. Cutting-edge implant rehabilitation design and management: A tapered abutment approach. Compendium 2017 July/August 38(7).

Small PN, Tarnow DP. Gingival recession around implants: a 1-year longitudinal prospective study. Int J Oral Maxillofac Implants. 2000 Jul–Aug;15(4):527–32.

Terheyden H, Lang NP, Bierbaum S, Stadlinger B. Osseointegration--communication of cells. Clin Oral Implants Res. 2012 Oct;23(10):1127–35. doi: 10.1111/j.1600-0501.2011.02327.x. Epub 2011 Nov 10.


Urdaneta RA, Leary J, Panetta KM, Chuang SK. The effect of opposing structures, natural teeth vs. implants on crestal bone levels surrounding single-tooth implants. Clin Oral Implants Res. 2014 Feb;25(2):e179–88. doi: 10.1111/clr.12087. Epub 2012 Dec 20.

Warren P, Chaffee N, Felton DA, Cooper LF. A retrospective radiographic analysis of bone loss following placement of TiO2 grit-blasted implants in the posterior maxilla and mandible. Int J Oral Maxillofac Implants. 2002 May–Jun;17(3):399–404. �




The following report summarises the fi rst paper presented during the What are the limits of immediate implant placement and immediate restoration? session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

One of the main advantages of immediate restoration is time. Both the patient and clinician can benefi t from reduced treatment times. However, in general practice it is diffi cult to know when this approach should be selected, or whether a delayed approach is more suitable.

The socket without buccal bone wallPaolo Fernando MesquitaEAO Congress Scientifi c Report; (3), 57–59, 2018.

The speaker identifi ed two triangular areas in fresh extraction sockets (Figure 1):

� the functional zone, which comprises mostly of residual bone (green)

� the aesthetic zone, which is closely related to the buccal bone wall (red)

An immediate implant should never be placed in the aesthetic triangle. The buccal bone wall protects the blood clot and graft materials, and supports the horizontal and vertical position of the aesthetic soft tissues.

There are several clinical advantages associated with immediate implant placement: less invasive; lower morbidity; fewer surgical procedures; shorter treatment time; and fi nally the possibility of immediate provisionalisation. Although there is suffi cient clinical evidence to consider immediate implant placement as a predictable option from a functional point of view (as high documented survival rates range from 96–100%), these fi gures are only slightly less than the conventional protocol. However, there are still concerns regarding the aesthetic outcomes of this approach.

Aesthetic issues

The biggest aesthetic issues related to this treatment option are: lack of buccal volume; greyish aspect and/or recession; those which are associated with physiological bone remodelling were surgically compensated. Loss of buccal volume, greyish colouring and marginal recessions usually indicate that no bone is remaining in the buccal area. This is a multifactorial problem which has been associated with: implant diameter and 3D position; thickness and integrity of the buccal bone wall; gingival biotype; gap fi lling and/or soft tissue augmentation; and design of the abutment and prosthesis.

Mean mid-facial recessions of –1.13 ± 0.87mm at 2–8 year follow-ups have been observed when the gap was not fi lled with biomaterials (Kan et al. 2011).

Several studies have claimed that fi lling the gap can compensate for natural resorption of the socket and improve results (according to CBCT images after

the treatment) (Degidi et al. 2013; Lee et al. 2014; Morimoto et al. 2015). However, some cases have been reported which show a buccal bone width of 2mm on the CBCT, and where a lack of volume is clearly seen in a clinical occlusal view. This indicates that the presence of buccal bone itself is not suffi cient to guarantee a natural aesthetic volume (Figures 2–3).

Pre-clinical and clinical studies have shown that reconstructing the internal portion of the socket is not enough to compensate for physiological post-extraction ridge reduction (Araujo et al. 2011; Novaes et al. 2012; Sanz et al. 2017).

Figure 1

Protect SupportBlood clot

GraftSoft Tissues

Anchorage

3-D position

Biology

osseointegration

Functional Anchorage BiologyZone Aesthetic Zone

residual residual residual residual

bone

apical

pa

la

ta

l

Bu

cc

al

“What’sthemainimportanceofthebuccalbonewallinthepostextractionsiteswhenweperformanimmediateimplantplacement?”

Figure 2

M6

Figure 3

NOCTG

2 Y


What happens when no CTG is used at immediate implants?

Two clinical studies following the same patient cohort used connective tissue grafts as a technique for resolving aesthetic problems. According to these studies, 5 out of 20 patients required connective tissue grafts (CTG) at the one-year follow-up. At the 5-year follow-up, 8 out of 17 patients required a CTG for aesthetic reasons. These aesthetic complications occurred only at the buccal area, whereas the interproximal areas were stable or even improved over time (Cosyn et al. 2013; Cosyn et al. 2016).

Other studies have used CTG as a standard protocol for treating intact sockets, with stable aesthetic outcomes and no mid-facial recessions.

It is important to follow a prosthetic protocol to handle the cervical area in different soft tissue conditions. The speaker stated that in his opinion, more than 50% of recessions are caused by prosthetic factors; he recommended that proper guidelines be adhered to (Clavijo & Blasi. 2017).

The stability of grafted soft tissue has been the subject of extensive evaluation (although only in the short-term). According to several clinical studies, mucosal thickness can be increased by an average of 1mm, although high rates of variability are present depending on other co-factors (Wiesner et al. 2010; Rungcharassaeng et al. 2012; De Bruyckere et al. 2015; Eghbali et al. 2016).

The speaker’s protocol

In (clinical) reality, the exact percentage of sockets which present buccal wall defects is diffi cult to gauge. According to Zitzmann et al. (1999), about 68% of clinical cases have some kind of defect. The literature presents numerous regenerative approaches for treating compromised sockets.

There are two factors to consider when deciding whether to place an immediate implant or a socket reconstruction: the residual bone and the gingival margin position. Moreover, two more factors should be taken into account to decide what hard and soft tissue procedures should be performed: the condition of the buccal plate and the tissue biotype (Figure 4).

Buccal plate defects may have different morphologies:

� V-shaped defects: these are self-contained and non-critical, and can be successfully treated by grafting the gap with Bio-Oss CollagenTM, without a membrane

� wider U-shaped defects: these do not protect the blood clot, and should be treated with a resorbable membrane and Bio-oss Collagen

� extensive apical and palatal defects: in this scenario, no residual bone remains to anchor the implant. Therefore, the author strongly suggested that socket reconstruction is the best treatment option

Take-home messages

� a fl apless or a minimally invasive envelope approach is important to protect and preserve the inter-proximal area, providing better vascular supply and facilitating hard and soft tissue reconstruction procedures

� proper implant diameter selection and correct prosthetically-driven positioning is essential for providing enough room for the reconstruction and the emergence profi le

� the reconstruction of the internal portion of the socket/bone defect is important, but may not be suffi cient to maintain the original gingival architecture

� the compensation of the outer portion of the socket with a CT graft seems to be essential in most cases in the aesthetic zone

� properly designed provisional restorations or customised healing abutments are essential for sealing the socket and supporting the soft tissues guiding a perfect gingival architecture

References

Araújo MG, Lindhe J. Socket grafting with the use of autologous bone: an experimental study in the dog. Clin Oral Implants Res. 2011 Jan;22(1):9–13. doi: 10.1111/j.1600-0501.2010.01937.x. Epub 2010 Nov 22.

Clavijo & Blasi. Quintessence of Dental Technology 2017; 40:67–88

Cosyn J, De Bruyn H, Cleymaet R. Soft tissue preservation and pink aesthetics around single immediate implant restorations: a 1-year prospective study. Clin Implant Dent Relat Res. 2013 Dec;15(6):847–57. doi: 10.1111/j.1708–8208.2012.00448.x. Epub 2012 Feb 29.

Cosyn J, Eghbali A, Hermans A, Vervaeke S, De Bruyn H, Cleymaet R. A 5-year prospective study on single immediate implants in the aesthetic zone. J Clin Periodontol. 2016 Aug;43(8):702–9. doi: 10.1111/jcpe.12571. Epub 2016 Jun 13.

De Bruyckere T, Eghbali A, Younes F, De Bruyn H, Cosyn J. Horizontal stability of connective tissue grafts at the buccal aspect of single implants: a 1-year prospective case series. J Clin Periodontol. 2015 Sep;42(9):876–82. doi: 10.1111/jcpe.12448. Epub 2015 Sep 16.

Degidi M, Daprile G, Nardi D, Piattelli A. Buccal bone plate in immediately placed and restored implant with Bio-Oss(®) collagen graft: a 1-year follow-up study. Clin Oral Implants Res. 2013 Nov;24(11):1201–5. doi: 10.1111/j.1600-0501.2012.02561.x. Epub 2012 Aug 13.

Figure 4

Tissue BiotypeBuccal PlateResidual bone Gingival MarginGingival Margin

IIP - ProtocolTissue BiotypeBuccal PlateGingival Margin

IIP - ProtocolImmediate Implant/restorationTissue Biotype

Thick

Intermediate

Thin

Class I

Class II

Class III

Class IV

Coronal

Level

Apical ≤4,0

Apical ≥4,0

Intact Fenestration

V-shape

U-shape

Immediate implant / Socket reconstruct ion Hard/Soft t issue Procedures


Eghbali A, De Bruyn H, Cosyn J, Kerckaert I, Van Hoof T. Ultrasonic Assessment of Mucosal Thickness around Implants: Validity, Reproducibility, and Stability of Connective Tissue Grafts at the Buccal Aspect . Clin Implant Dent Relat Res. 2016 Feb;18(1):51–61. doi: 10.1111/cid.12245. Epub 2014 Jul 17.

Kan JY, Roe P, Rungcharassaeng K, Patel RD, Waki T, Lozada JL, Zimmerman G. Classification of sagittal root position in relation to the anterior maxillary osseous housing for immediate implant placement: a cone beam computed tomography study. Int J Oral Maxillofac Implants. 2011 Jul–Aug;26(4):873–6.

Lee EA, Gonzalez-Martin O, Fiorellini J. Lingualized flapless implant placement into fresh extraction sockets preserves buccal alveolar bone: a cone beam computed tomography study. Int J Periodontics Restorative Dent. 2014 Jan–Feb;34(1):61–8. doi: 10.11607/prd.1807.

Morimoto T, Tsukiyama Y, Morimoto K, Koyano K. Facial bone alterations on maxillary anterior single implants for immediate placement and provisionalization following tooth extraction: a superimposed cone beam computed tomography study. Clin Oral Implants Res. 2015 Dec;26(12):1383–9. doi: 10.1111/clr.12480. Epub 2014 Sep 2.

Novaes AB Jr, Suaid F, Queiroz AC, Muglia VA, Souza SL, Palioto DB, Taba M Jr, Grisi MF. Buccal bone plate remodeling after immediate implant placement with and without synthetic bone grafting and flapless surgery: radiographic study in dogs. J Oral Implantol. 2012 Dec;38(6):687–98. doi: 10.1563/AAID-JOI-D-10-00176. Epub 2011 Sep 9.

Rungcharassaeng K, Kan JY, Yoshino S, Morimoto T, Zimmerman G. Immediate implant placement and provisionalization with and without a connective tissue graft: an analysis of facial gingival tissue thickness. Int J Periodontics Restorative Dent. 2012 Dec;32(6):657–63.

Sanz M, Ferrantino L, Vignoletti F, de Sanctis M, Berglundh T. Guided bone regeneration of non-contained mandibular buccal bone defects using deproteinized bovine bone mineral and a collagen membrane: an experimental in vivo investigation. Clin Oral Implants Res. 2017 Nov;28(11):1466–1476. doi: 10.1111/clr.13014. Epub 2017 Mar 27.

Tsuda H, Rungcharassaeng K, Kan JY, Roe P, Lozada JL, Zimmerman G. Peri-implant tissue response following connective tissue and bone grafting in conjunction with immediate single-tooth replacement in the esthetic zone: a case series. Int J Oral Maxillofac Implants. 2011 Mar–Apr;26(2):427–36.

Wiesner G, Esposito M, Worthington H, Schlee M. Connective tissue grafts for thickening peri-implant tissues at implant placement. One-year results from an explanatory split-mouth randomised controlled clinical trial. Eur J Oral Implantol. 2010 Spring;3(1):27–35.

Zitzmann NU, Schärer P, Marinello CP. Factors influencing the success of GBR. Smoking, timing of implant placement, implant location, bone quality and provisional restoration. J Clin Periodontol 1999;26:673–682. �




The following report summarises the second paper presented during the What are the limits of immediate implant placement and immediate restoration? session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

One of the main advantages of immediate restoration is time. Both the patient and clinician can benefit from reduced treatment times. However, in general practice it is difficult to know when this approach should be selected, or whether a delayed approach is more suitable.

The approach to posterior wide socketsOtto ZuhrEAO Congress Scientific Report; (3), 60–61, 2018.

Over the past few decades, there has been a shift from using traditional criteria to measure treatment success to using patient-reported outcome measures under the heading of Oral Health-Related Quality of Life (OHRQoL). From the patient’s perspective, the four parameters of treatment success are:

� comfortable long-term function � a proper aesthetic appearance � low morbidity and treatment time � reasonable cost

These must also be incorporated into our decision-making process.

As in the frontal area, immediate implant placement and restoration in molar areas is supported by extensive clinical documentation. Very promising survival rates (99.0% for immediate placement and 97.9% for immediate provisionalisation or loading) have been reported in a meta-analysis (Atieh et al. 2010).

The scientific evidence surrounding these reported success rates is poor, however, due to the lack of reported complications. The speaker identified three categories of complications: technical, aesthetic and biological:

� technical complications do not seem to be an issue between immediate and delayed protocols

� aesthetic complications are not a priority in molar areas

� biological complications may be the result of epithelial down-growth and the formation of a long epithelial junction in wide sockets

In a clinical study, bone was measured at the time of implant placement and again during re-entry. Although most of the gaps were filled with new bone, some were only partially filled, and the more coronal part of the implant was surrounded by connective tissue (Botticelli et al. 2004). It remains unclear whether these histologic findings may facilitate the occurrence of future biological complications.

A more recent multicentre randomised clinical trial concluded that the thickness of the buccal bone wall and the dimension of the horizontal gap have a major impact on the level of post-extraction changes in hard tissues (Ferrus et al. 2010). The speaker asked: ‘Can these factors be avoided or at least compensated?’

According to an experimental study in the dog model, filling gaps with Bio-Oss collagen can increase levels of hard tissue formation and the level of marginal bone-to-implant contact (Araujo et al. 2011).

Technically easy?

With this in mind, we have to recognise that immediate protocols in molar sites can offer more advantages. The only problem is that the procedure is technically difficult; for that reason it should not be viewed as a simple technique or an ‘easy’ option.

The speaker also described a clinical approach which can be useful for increasing the indications of immediate placement in premolar or molar areas. It should be noted that this technique is based on the speaker’s own experience after the socket-shield technique, and is not yet evidence-based. It involves preparing an implant osteotomy through tooth roots. An experimental study in the dog model (Hürzeler et al. 2010) has demonstrated that it is possible to prepare the osteotomy through the root. The root can even be used as a guide for stabilising the drills and can be taken out once the osteotomy is finished. In molar sites, this approach can have enormous practical advantages and make the procedure easier (Rebele et al. 2013) (Figures 1–6).

This approach can be called a ‘pre-extractive inter-radicular implant bed preparation’. The speaker is conducting a prospective cohort study and at the time of this presentation has placed 27 immediate implants in molars using this procedure; thus far, no complications have been recorded (Zuhr et al. In preparation).


References

Araújo MG, Lindhe J. Socket grafting with the use of autologous bone: an experimental study in the dog. Clin Oral Implants Res. 2011 Jan;22(1):9–13. doi: 10.1111/j.1600-0501.2010.01937.x. Epub 2010 Nov 22.

Atieh MA, Payne AG, Duncan WJ, de Silva RK, Cullinan MP. Immediate placement or immediate restoration/loading of single implants for molar tooth replacement: a systematic review and meta-analysis. Int J Oral Maxillofac Implants. 2010 Mar–Apr;25(2):401–15.

Botticelli D, Berglundh T, Lindhe J. Hard-tissue alterations following immediate implant placement in extraction sites. J Clin Periodontol. 2004 Oct;31(10):820–8.

Ferrus J, Cecchinato D, Pjetursson EB, Lang NP, Sanz M, Lindhe J. Factors influencing ridge alterations following immediate implant placement into extraction sockets. Clin Oral Implants Res. 2010 Jan;21(1):22–9. doi: 10.1111/j.1600-0501.2009.01825.x. Epub 2009 Nov 13.

Hürzeler MB1, Zuhr O, Schupbach P, Rebele SF, Emmanouilidis N, Fickl S. The socket-shield technique: a proof-of-principle report. J Clin Periodontol. 2010 Sep;37(9):855–62. doi: 10.1111/j.1600-051X.2010.01595.x.

Rebele SF, Zuhr O, Hürzeler MB. Pre-extractive interradicular implant bed preparation: case presentations of a novel approach to immediate implant placement at multirooted molar sites. Int J Periodontics Restorative Dent. 2013 Jan–Feb;33(1):89–96. �



Figure 2

Figure 4

Figure 1

Figure 6

Figure 3

Figure 5


The following report summarises the first paper presented during the The combination of dental implants and orthodontic therapy in the functional rehabilitation of partially edentulous patients session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Missing incisors: implants vs space closure looking at crucial detailsMarco RosaEAO Congress Scientific Report; (3), 62–63, 2018.

Orthodontics vs implantsRecent scientific evidence supports a different approach for rehabilitating missing incisors. Orthodontics is becoming an increasingly common treatment option for these patients.

Space closure is now a predictable procedure: periodontal tissues can be modified using orthodontic techniques, and even if restorations are required, orthodontics can match the long-term patient-centred objectives of current therapies.

The speaker presented a case involving a hopeless and malpositioned tooth 21. They identified the following key questions:

� how should the implant be placed? � how can we regenerate the alveolar bone? � how can we rebuild soft tissue and the papilla?

Each of these problems can be solved with orthodontic space closure. In this case, orthodontics were the best method for remodelling the soft tissue and periodontal profile.

Another complex case was presented. This case involved a bridge and two missing adjacent incisors; after space closure, the remodelling of the soft tissue margins had to be controlled orthodontically using a combination of intrusion and extrusion.

In some cases, space closure must be finished with minimally invasive ‘no-prep’ composite restorations which require minimal maintenance, but are stable 23 years after closure. In cases involving missing incisors and severe crowding, space closure is the best strategy also in order to correct malocclusion.

Pros and cons

The main advantages of space closure is that, in front of a growing patient, treatment can be finished before adolescence in a predictable and minimally invasive way. Implant treatment can be performed only at the end of growth and shows higher complication rates. The implant substitution presents difficulties with clinical management of the periodontal tissues, and is associated with complications such as peri-implantitis (Derks & Tomasi. 2015). Additionally, peri-implant soft tissues can often exhibit recessions, black triangles and

inadequate colour or texture. Another problem which may arise is unpredictable infra-occlusion due to vertical eruption of other teeth, especially in young patients (Bernard et al. 2004; Zitzmann et al. 2015). Under these circumstances, implants are unpredictable in the long-term: 66% of patients had at least one complication over a follow-up of 16–22 years (Dierens et al. 2016).

The main objections to space closure alternatives are based on: compromised occlusal function, reopening spaces over time, and the resulting ‘non-natural’ appearance. For several decades, however, the literature has shown that patients treated with space closure were healthier, had no occlusal disorders or temporo-mandibular disorders (TMD), and that the maintenance of natural dentition in patients with missing incisors is a valid treatment option (Nordquist & McNeill. 1975; Robertsson & Mohlin. 2000). A recent comparison of space closure with modern implants in 20 patients yielded similar, well-accepted aesthetic results: better periodontal health associated with space closure and clear infra-occlusion with implants (Jamilian et al. 2015). The general conclusion is that periodontal health is better with space closure but aesthetics have to be improved.

Improving aesthetics

To improve aesthetics, teeth should be restored after orthodontic space closure (Rosa & Zachrisson. 2001). During space closure, the canines can be extruded and premolars intruded to ideally level the gingival margins, and both should be modified with a restoration. The vertical movements will level the gingival margins but may also produce one-wall vertical bone defects, which can be flossed effectively.

Patients with congenitally missing lateral incisors have small teeth and generally in these cases the central incisors also have to be restored to produce a natural-looking, balanced smile. In many of those patients, the centrals had to be widened and lengthened (Rosa & Zachrisson. 2007; Mirabella et al. 2012; Ramazanzadeh et al. 2013; Wright et al. 2016).

A recent study recommended intruding the premolars first and extruding canines to mimic the function corresponding to their new positions. It found that the osseous defects caused by intrusion did not present a


special risk for periodontal tissue deterioration or for TMD in the long-term (Rosa et al. 2016).

Currently, malocclusions can be treated with space closure using bone anchorage through orthodontic mini-implants, even in unilateral cases. The speaker identified several ‘key words’ to be considered in treatment plans: malocclusion, tooth size, smile line and patient age.

Take-home message

The speaker stated that he does not view single implants as the main option for treating patients with missing incisors, especially in young patients and when the gingival margins are visible. Instead, resin-bonded bridges or even cantilevered prosthetics may be an important alternative in the future.

Preserving deciduous teeth and performing orthodontic space closure is certainly not the easiest approach, but it is the most conservative for young patients. According to Zachrisson, a root is almost always better than an implant, so the treatment principle should be: natural teeth in the aesthetic area and implants in posterior areas.

The speaker concluded that:

� implants have an unpredictable long-term prognosis

� space closure is an evidence-based treatment � currently, spaces can be closed in almost all

malocclusions, so it is the preferred option for young patients

� as patients with missing incisors have small teeth, several restorations of the anterior teeth are highly recommended to improve the aesthetic outcome

References

Bernard JP, Schatz JP, Christou P, Belser U, Kiliaridis S. Long-term vertical changes of the anterior maxillary teeth adjacent to single implants in young and mature adults. A retrospective study. J Clin Periodontol. 2004 Nov;31(11):1024–8.

Derks J, Tomasi C. Peri-implant health and disease. A systematic review of current epidemiology. J Clin Periodontol. 2015 Apr;42 Suppl 16:S158–71. doi: 10.1111/jcpe.12334.

Dierens M, De Bruyn H, Kisch J, Nilner K, Cosyn J, Vandeweghe S. Prosthetic Survival and Complication Rate of Single Implant Treatment in the Periodontally Healthy Patient after 16 to 22 Years of Follow-Up. Clin Implant Dent Relat Res. 2016 Feb;18(1):117–28.

Jamilian A, Perillo L, Rosa M. Missing upper incisors: a retrospective study of orthodontic space closure versus implant. Prog Orthod. 2015 Feb 25;16:2. doi: 10.1186/s40510-015-0072-2.

Mirabella AD, Kokich VG, Rosa M. Analysis of crown widths in subjects with congenitally missing maxillary lateral incisors. Eur J Orthod. 2012 Dec;34(6):783–7.

Nordquist GG, McNeill RW, Orthodontic vs. restorative treatment of the congenitally absent lateral incisor--long term periodontal and occlusal evaluation. J Periodontol. 1975 Mar;46(3):139–43.

Ramazanzadeh BA, Ahrari F, Hajian S. Evaluation of tooth size in patients with congenitally-missing teeth. J Dent Res Dent Clin Dent Prospects. 2013 Winter;7(1):36–41. doi: 10.5681/joddd.2013.006. Epub 2013 Feb 21.

Robertsson S, Mohlin B. The congenitally missing upper lateral incisor. A retrospective study of orthodontic space closure versus restorative treatment. Eur J Orthod. 2000 Dec;22(6):697–710.

Rosa M, Lucchi P, Ferrari S, Zachrisson BU, Caprioglio A. Congenitally missing maxillary lateral incisors: Long-term periodontal and functional evaluation after orthodontic space closure with first premolar intrusion and canine extrusion. Am J Orthod Dentofacial Orthop. 2016 Mar;149(3):339–48.

Rosa M, Zachrisson BU. Integrating esthetic dentistry and space closure in patients with missing maxillary lateral incisors. J Clin Orthod. 2001 Apr;35(4):221–34.

Rosa M, Zachrisson BU. Integrating space closure and esthetic dentistry in patients with missing maxillary lateral incisors. J Clin Orthod. 2007 Sep;41(9):563–73; quiz 424.

Wright J, Bosio JA, Chou JC, Jiang SS. Maxillary lateral incisor agenesis and its relationship to overall tooth size. J Prosthet Dent. 2016 Feb;115(2):209–14. doi: 10.1016/j.prosdent.2015.07.010. Epub 2015 Oct 14.

Zitzmann NU, Özcan M, Scherrer SS, Bühler JM, Weiger R, Krastl G. Resin-bonded restorations: a strategy for managing anterior tooth loss in adolescence. J Prosthet Dent. 2015 Apr;113(4):270–6. doi: 10.1016/j.prosdent.2014.09.028. �




The following report summarises the second and third papers presented during the The combination of dental implants and orthodontic therapy in the functional rehabilitation of partially edentulous patients session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

The use of implant-supported prostheses to restore function after orthodontic therapyJavier Casas and Cristina SuárezEAO Congress Scientifi c Report; (3), 64–65, 2018.

Orthodontics are being used with increasing regularity as an adjunctive treatment to facilitate implant rehabilitations. This approach may be carried out in two ways:

1. Correcting the position of the teeth to allow implant placement in a suitable prosthetically driven location

2. Developing the implant site with bone augmentation and soft tissue displacement

To highlight the relationship between orthodontics and implants, the speaker described two different clinical scenarios:

1. Correction of the occlusal plane by a combination of orthodontics and implants

2. Bone augmentation by orthodontic means

Implants in orthodontic anchorage

The speaker presented a case involving a partially edentulous patient: the occlusal plane was altered by alternating over-eruptions and edentulous spaces. The treatment plan involved implant placement, and the use of them as orthodontic anchorage to intrude the extruded teeth and to level the occlusal plane (Figure 1).

For cases such as this, a standard healing protocol has traditionally been recommended (Roberts et al. 1984; Majzoub et al. 1999; Huang et al. 2005). In 2010, however, a comparative long-term clinical study concluded that implants could be used immediately for orthodontic anchorage and that the conventional four-month healing period was not necessary (Palagi et al. 2010). A recent histomorphometric study in the dog model corroborated these fi ndings: it found that immediate static loads do not interfere with osseointegration, and that bone/implant contact levels and the amount of lamellar bone were the same in samples from immediate and delayed orthodontic loading (Rismanchian et al. 2017).

Another clinical study assessing peri-implant probing depth and marginal bone levels suggested that stable intra-oral orthodontic anchorage did not compromise the health of peri-implant tissues or the longevity of the implant (Marins et al. 2016).

Ortho-induced bone formationThe regenerative potential of extraction alveoli can be harnessed for implant site development by means of extrusion. The speakers stated that hopeless teeth are not useless teeth. The periodontal ligament can be extruded in an incisal direction to develop bone and gingiva for a potential site for an implant. This concept was developed by Salama and colleagues, who also published a classifi cation system based on the severity of the initial defect (Salama et al. 1993).

The speakers outlined several orthodontic considerations (Amato et al. 2012; Alsahhaf & Att. 2016; Antoun et al. 2017):

� brackets are placed gingivally � occlusal contacts should be re-contoured in

each appointment, remarking that this is very important for the success of this procedure

� the wire is activated 1mm vertically at one-month intervals

� forces have to be light and constant � it is recommended to move about 1mm per month � an overcorrection of 2mm and a retention period

of 2–6 months are advisable � periodontal status should be monitored every

two weeks

Perio-Pro considerations (Hochman et al. 2014):

Hard tissues: orthodontic force creates tension on the periodontal ligament fi bres, stretching them on the bone surface and provoking cellular changes which lead to the formation of new bone.

Soft tissues: an anatomically based classifi cation in three types was defi ned depending on the level of keratinised tissue present:

Figure 1

i m m e d i a t e i m p l a n t l o a d i n g


� Type I: if the muco-gingival line (blue) is apical to the level of the crest (green)

� Type II: if the opposite is present (Figure 2) � Type III: if the defect is bigger

A systematic review comparing orthodontic extrusion with bone grafting prior to implant placement concluded that both methods are equally effective and neither is superior (Magkavali-Trikka et al. 2015).

Main concepts presented

The speakers made a number of statements based on different types of evidence:

� shortening the healing period before applying orthodontic forces to implants does not seem to disturb the osseointegration process (evidence type II: prospective studies)

� preservation/regeneration and immediate/early implant placement are the best treatment options for maintaining bone levels (evidence type I: randomised clinical trials)

� forced orthodontic eruption may be an effective and less invasive method for implant site development (evidence type III: clinical experience)

� comparing forced eruption with bone grafting, both methods of implant site development are equally effective (evidence type I: randomised clinical trials)

References

Alsahhaf A, Att W. Orthodontic extrusion for pre-implant site enhancement: Principles and clinical guidelines. J Prosthodont Res. 2016 Jul;60(3):145–55. doi: 10.1016/j.jpor.2016.02.004. Epub 2016 Mar 12

Amato F, Mirabella AD, Macca U, Tarnow DP. Implant site development by orthodontic forced extraction: a preliminary study. Int J Oral Maxillofac Implants. 2012 Mar–Apr;27(2):411–20.

Antoun JS, Mei L, Gibbs K, Farella M. Effect of orthodontic treatment on the periodontal tissues. Periodontol 2000. 2017 Jun;74(1):140–157. doi: 10.1111/prd.12194.

Hochman MN, Chu SJ, Tarnow DP. Orthodontic extrusion for implant site development revisited: A new classifi cation determined by anatomy and clinical outcomes. Semin Orthod 2014; 20:208–227.

Huang L-H, Shotwell JL, and Wang H-L. Dental Implants for Orthodontic Anchorage. Am J Orthod Dentofacial Orthop 2005;127:713–22.

Magkavali-Trikka P, Kirmanidou Y, Michalakis K, Gracis S, Kalpidis C, Pissiotis A, Hirayama H. Effi cacy of two site-development procedures for implants in the maxillary esthetic region: a systematic review. Int J Oral Maxillofac Implants. 2015 Jan–Feb;30(1):73–94. doi: 10.11607/jomi.3652.

Majzoub Z, Finotti M, Miotti F, Giardino R, Aldini NN, G Cordioli. Bone response to orthodontic loading of endosseous implants in the rabbit calvaria: early continuous distalizing forces. European Journal of Orthodontics, Volume 21, Issue 3, 1 June 1999, Pages 223–230, https://doi.org/10.1093/ejo/21.3.223.

Marins Bde R, Pramiu SE, Busato MC, Marchi LC, Togashi AY. Peri-implant evaluation of osseointegrated implants subjected to orthodontic forces: results after three years of functional loading. Dental Press J Orthod. 2016 Mar–Apr;21(2):73–80. doi: 10.1590/2177-6709.21.2.073-080.oar.

Palagi LM, Sabrosa CE, Gava EC, Baccetti T, Miguel JA. Long-term follow-up of dental single implants under immediate orthodontic load. Angle Orthod. 2010 Sep;80(5):807–11. doi: 10.2319/021010-86.1.

Rismanchian M, Raji SH, Razavi SM, Rick DT, Davoudi A. Application of Orthodontic Immediate Force on Dental Implants: Histomorphologic and Histomorphometric Assessment. Ann Maxillofac Surg. 2017 Jan–Jun;7(1):11–17. doi: 10.4103/ams.ams_35_15.

Roberts WE, Smith RK, Zilberman Y, Mozsary PG, Smith RS. Osseous adaptation to continuous loading of rigid endosseous implants. Am J Orthod. 1984 Aug;86(2):95–111.

Salama H, Salama M. The role of orthodontic extrusive remodeling in the enhancement of soft and hard tissue profiles prior to implant placement: a systematic approach to the management of extraction site defects. Int J Periodontics Restorative Dent. 1993 Aug;13(4):312–33. �



Figure 2

2 . s o f t t i s s u e s

• Perio-pro considerations Semin Orthod. 2014;20: 208-27

2 . s o f t t i s s u e s

SeminSeminSemin OrthodOrthodOrthodOrthod. 2014;20: 208. 2014;20: 208

type 1 type 2

p r e - t r e a t m e n t a n a t o m y b o n e & s o f t t i s s u e s r e s p o n s e t o F O E


The following report summarises the fi rst paper presented during the The restorative treatment of the partially edentulous periodontitis patient session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

This session focused on how to treat periodontitis patients. As an overview, the session chairs identifi ed three main options:

� conservative: this approach involves scaling, root planing and maintenance. It has a good long-term prognosis but can also lead to aesthetic problems caused by tissue recession

� conventional: the endo-perio-prosthetic approach aims to facilitate hygiene and eliminate furcations by radicular resections. However, cost, as well as periodontal and aesthetic variables, could affect the prognosis

� implant: extracting teeth and placing implants. In well controlled patients, this approach allows us to achieve good outcomes, but the frequent occurrence of peri-implantitis in current rough implant surfaces is a complication which is diffi cult to manage

The chairs presented a borderline clinical case, for which each of the speakers tackled and presented their own treatment options.

The conservative approachIgnacio Sanz MartínEAO Congress Scientifi c Report; (3), 66–67, 2018.

The prognosis of the disease

The ‘conservative approach’ is an umbrella term which includes all measures for preventing and treating caries and periodontitis, and is aimed at preserving the existing dentition. Procedures following this approach are not sensitive to technique and are cost-effective; they are, however, often overlooked and undervalued by the patient.

The issue is that we do not know how each individual patient will respond to treatment. The decision-making process must therefore be based on a ‘probable prognosis’. In fact, the term ‘prognosis’ is itself confusing, as it is impossible to predict the course and outcome of multifactorial diseases.

A study following the natural progression of periodontitis in a population in Sri Lanka over a 40-year period was recently published. The study found that the progression of periodontitis over time was stable, regardless of the initial severity of the disease (Ramseier et al. 2017).

Regarding the infl uence of age, there are particular ages when the prevalence of dental disease is particularly high, and during which it is possible that preventive measures may have an increased effect (Kassebaum et al. 2014; 2015).

A successful and cost-eff ective treatment

A 15-year follow-up clinical study of patients treated for periodontitis monitored tooth loss, and found that 83% of patients had good long-term responses (Hirschfeld & Wasserman. 1978) (Figure 1). Also, subgingival instrumentation was shown to reduce probing depth and improve attachment levels in direct proportion to the severity of the initial base-line records (Philstrom et al. 1981).

There is currently evidence available supporting the benefi ts of adjunctive therapies (Smiley et al. 2015). These therapies do not show high reductions of pocket depth, but the simplicity and low cost associated with these treatments makes them highly recommended (Figures 2–3).

When the conservative approach is not enoughAlthough good clinical outcomes are systematically achieved with low-cost treatment options in the aesthetic area, tissue recession is the main limiting factor.

In cases involving intra-osseous defects a supplementary surgical treatment is usually required. This can also be performed in a minimally invasive way, however, as the literature shows clinical attachment increases between 3–6mm.

In cases with furcation defects, long-term evidence has shown that it is possible to gain access with an apically repositioned fl ap. According to the literature, after a 15–25-year follow-up, 75% of patients were able to maintain the treated molars. In most of the remaining 25%, the reason the molars were lost was non-restorable caries.

Figure 1

_ treatment and disease progression

- Well maintained group

- Downhill group

- Extreme downhill group

Long-Term Survey of Tooth Loss in 600 Treated Periodontal Patients. Hirschfeld L, Wasserman B, J Periodontol 1978;49:225-237

Maintained Downhill Ext Downhill

lost 0-3 teeth

lost 4-9 teeth

lost 10-23 teeth


When teeth are lostA shortened dental arch has been found to suffi ciently provide proper function and a similar oral health-related quality of life (OHRQoL) for patients lacking molars (provided that at least four occlusal units are available in each side) (Khan et al. 2017).

Similarly, resin-bonded adhesive bridges in anterior areas (Maryland type) can provide restorative options with high survival rates after a mean observational period of fi ve years. Adhesive bridges with zirconia frameworks and a single-retainer design seem to perform the best in a current systematic review (Thoma et al. 2017).

On the other hand, teeth with very little remaining structure can be successfully restored by adhesive restorations with low complication rates, according to a systematic review (Morimoto et al. 2016).

In spite of this, we cannot always carry out conservative treatments and rehabilitate patients with lost or hopeless teeth. Implants can offer survival rates of about 95% at fi ve years and 92% at ten years. But survival is not the same as success.

‘Success’ implies absence of complications, yet complications are common in implant treatments.

Technical complications have been estimated to affect 39% of implants; this is more than double the number of complications in tooth-supported reconstructions (15.7%) (Pjetursson et al. 2007). Regarding biological complications, roughly 22% of patients present peri-implantitis. The onset of the disease is generally 3–5 years after loading, and develops even in non-periodontal patients. There is currently no predictable treatment approach available.

To conclude, the speaker stated that the conservative approach must not be forgotten, both from the biological and the restorative point of view. There is often a second opportunity to recover and maintain oral health in periodontal patients (Figure 4).

References

Hirschfeld L, Wasserman B. A long-term survey of tooth loss in 600 treated periodontal patients. J Periodontol 1978 May;49(5):225–37.

Kassebaum NJ et al. Global burden of severe periodontitis in 1990–2010: a systematic review and meta-regression. J Dent Res. 2014 Nov;93(11):1045–53.

Kassebaum NJ, Bernabé E, Dahiya M, Bhandari B, Murray CJ, Marcenes W. Global burden of untreated caries: a systematic review and metaregression. J Dent Res. 2015 May;94(5):650–8.

Khan S, Chikte U, Omar R. Impact of Removable Partial Dental Prostheses on the Oral Health-Related Quality of Life of a South African Cohort with Varied Distributions of Missing Posterior Teeth. J Prosthodont. 2017 Oct 25.

Pihlstrom BL, Ortiz-Campos C, McHugh RB. A randomized four-years study of periodontal therapy. J Periodontol. 1981 May;52(5):227–42.

Pjetursson BE, Brägger U, Lang NP, Zwahlen M. Comparison of survival and complication rates of tooth-supported fi xed dental prostheses and implant-supported FDPs and single crowns. Clin Oral Implants Res. 2007 Jun;18 Suppl 3:97–113.

Ramseier CA, Anerud A, Dulac M, Lulic M, Cullinan MP, Seymour GJ, Faddy MJ, Bürgin W, Schätzle M, Lang NP. Natural history of periodontitis: Disease progression and tooth loss over 40 years. J Clin Periodontol. 2017 Dec;44(12):1182–1191.

Smiley CJ et al. Evidence-based clinical practice guideline on the nonsurgical treatment of chronic periodontitis by means of scaling and root planing with or without adjuncts. J Am Dent Assoc. 2015 Jul;146(7):525–35.

Thoma DS, Sailer I, Ioannidis A, Zwahlen M, Makarov N, Pjetursson BE. A systematic review of the survival and complication rates of resin-bonded fixed dental prostheses after a mean observation period of at least 5 years. Clin Oral Implants Res. 2017 Nov;28(11):1421–1432. �



Figure 2

Local Antibiotics Anti-inflammatories Probiotics

Host ModulatorsAntiseptics

_Adjunctive therapies

Systemic Antibiotics

Systematic review and meta-analysis on the nonsurgical treatment of chronic periodontitis by means of scaling and root planing with or without adjuncts. Smiley et al. J Am Dent Assoc. 2015 Jul;146(7):508-24.

Figure 3

Local Antibiotics Anti-inflammatories Probiotics

Host ModulatorsAntiseptics

_Adjunctive therapies

Systemic Antibiotics

Systematic review and meta-analysis on the nonsurgical treatment of chronic periodontitis by means of scaling and root planing with or without adjuncts. Smiley et al. J Am Dent Assoc. 2015 Jul;146(7):508-24.

0.35mm 0.35mm

0.64mm

0.40mm

0.40mm0.38mm

Figure 4

Main concepts presented Based on

1. Conservative therapy has shown to be effective in arresting and preventing periodontal disease and caries

TYPE I Randomised Clinical Trials

2. Patients expectations and risk profile must be evaluated in the decision-making

TYPE II Observational studies

3. Conservative approaches may be considering when restoring the high risk profile patient

TYPE III Personal opinion


The following report summarises the second paper presented during the The restorative treatment of the partially edentulous periodontitis patient session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

This session focused on how to treat periodontitis patients. As an overview, the session chairs identified three main options:

� conservative: this approach involves scaling, root planing and maintenance. It has a good long-term prognosis but can also lead to aesthetic problems caused by tissue recession

� conventional: the endo-perio-prosthetic approach aims to facilitate hygiene and eliminate furcations by radicular resections. However, cost, as well as periodontal and aesthetic variables, could affect the prognosis

� implant: extracting teeth and placing implants. In well controlled patients, this approach allows us to achieve good outcomes, but the frequent occurrence of peri-implantitis in current rough implant surfaces is a complication which is difficult to manage

The chairs presented a borderline clinical case, for which each of the speakers tackled and presented their own treatment options.

The perio-prostho approachIgnacio Sanz SánchezEAO Congress Scientific Report; (3), 68–70, 2018.

Complex cases

In Spain, about 8–10% of the general population are estimated to suffer from advanced periodontitis (Carasol et al. 2016). This kind of patient presents complex problems which cannot be solved with a conservative approach alone. The speaker presented a clinical case to illustrate this.

It is clear that using a conservative approach it is possible to manage most of the periodontitis cases and even to recover part of the lost attachment (Cobb CM. 2002; Hung & Douglas 2002). The treatment should therefore start with this. But in this case, the conservative treatment had limitations which would be confirmed during the patient’s re-evaluation (Figure 1).

Although there had been improvement in plaque levels and bleeding on probing indices at the re-evaluation, the pockets were still too deep to be properly maintained. At this point, three options were available:

1. Do nothing, and schedule the patient for a support and maintenance protocol

2. Extract the teeth with poor prognoses and place implants

3. Perform periodontal surgery for pocket reduction and periodontal health recovery

Option 1. The literature shows disease progression in patients with residual pockets ≧ 6mm after scaling and root planning. It is likely that these patients will continue to lose bone, and more likely that teeth will be lost (Renvert & Persson. 2002). When residual pockets are > 7mm, the risk of losing the teeth increases 64-fold (Matuliene et al. 2008). A conservative treatment approach alone for these patients is therefore not advised.

Option 2. All teeth with a questionable prognosis would have to be extracted and replaced with implants when it is indicated. However, there is strong evidence in the literature linking this type of patient with risk factors for peri-implantitis (Heitz-Mayfield L. 2008; Renvert & Polyzois. 2015). Therefore, it does not make sense to try to restore periodontal health by extracting teeth that are still viable in order to place risky implants.

Option 3. This option involves aiming to get access to the diseased root areas and regenerate periodontal tissue. According to the literature, residual PPD > 6mm represents an incomplete

Figure 1

SRP_ LIMITATIONS

• Deep pockets

• Intra-osseous defects

• Craters

• Furcations II - III

• Deep grooves

Figure 2

Health Mucositis/Gingivitis

Peri-implantitis/ Periodontitis

Primary Prevention Secondary Prevention

Tertiary Prevention


periodontal treatment outcome and requires further therapy (Matuliene et al. 2008). In pockets > 6mm, a systematic review has confi rmed that surgical debridement can achieve better results than scaling and root planning (Heitz-Mayfi eld et al. 2002). The speaker selected this option.

Maintenance and implants in perio patientsThe importance of long-term maintenance of periodontal health is supported by scientifi c evidence. As periodontally treated teeth are usually mobile, improving function using conventional splint therapy is a feasible option. The literature supports the long-term success of full-arch prostheses in perio patients (Nyman et al. 1975; Nyman & Lindhe. 1979; Carnevale et al. 1998). According to the speaker, dental implants currently represent a lower biologic challenge than conventional full-arch bridges for these cases; he recommended that implants should be placed only where teeth have been lost.

Implants can be placed in periodontally compromised patients provided that: the patient is fully informed of the risk of peri-implantitis; the patient stops smoking; proper plaque control is maintained; a supportive therapy protocol is arranged; and technical complications are prevented (Smith et al. 2017).

Implant treatment also shows positive outcomes for patient satisfaction, with an OHRQoL score similar to that of a healthy patient (Fischer et al. 2015).

Prevention (Figure 2)

According to the consensus report of the 11th European Workshop on Periodontology (Jepsen et al. 2015), strategies for primary and secondary

prevention are needed. Primary prevention measures should be carried out not only in healthy teeth but also at early signs of infl ammation. Secondary prevention focuses on teeth and implants already treated.

In practice, the effectiveness of supportive periodontal treatment was demonstrated more than three decades ago by a study which compared strict protocols with simple visits once a year (Axelsson & Lindhe. 1981) (Figures 3–4). In patients at risk of peri-implantitis, controls at fi ve or six months are recommended (Monje et al. 2015).

The speaker summarised the evidence in the literature in Figure 5.

References

Axelsson P, Lindhe J. The signifi cance of maintenance care in the treatment of periodontal disease. J Clin Periodontol. 1981 Aug;8(4):281–94.

Carasol M, Llodra JC, Fernández-Meseguer A, Bravo M, García-Margallo MT, Calvo-Bonacho E, Sanz M, Herrera D. Periodontal conditions among employed adults in Spain. J Clin Periodontol. 2016 Jul;43(7):548–56. doi: 10.1111/jcpe.12558. Epub 2016 May 12.

Carnevale G, Pontoriero R, di Febo G. Long-term effects of root-resective therapy in furcation-involved molars. A 10-year longitudinal study. J Clin Periodontol. 1998 Mar;25(3):209–14.

Cobb CM. Clinical signifi cance of non-surgical periodontal therapy: an evidence-based perspective of scaling and root planing. J Clin Periodontol. 2002 May;29 Suppl 2:6–16.

Fischer KR, Lindner I, Fickl S. Implant treatment in periodontally compromised subjects--quality of life and patient satisfaction. Clin Oral Investig. 2016 May;20(4):697–702. doi: 10.1007/s00784-015-1561-x. Epub 2015 Aug 15.

Figure 4

0

25

50

75

100

Plaque

0

25

50

75

100

Recall NonRecall

Bleeding

6 years

Initial Baseline 3years 6years Initial Baseline 3years 6years

Figure 5

Mainconceptspresented Basedon

TheTreatmentOfAdvancedPeriodontitisCanAchievePredictableResultsOverTimeInTermsOfToothLossAndPeriodontalHealth

TYPEIRandomisedClinicalTrials

TheRestorativeTreatmentOfTheAdvancedPeriodontalPatientCanOfferPredictableResultsInTermsOfRestoringFunctionAndAesthetics

TYPEIIObservationalstudies

ImplantsPlacedInThePartiallyEdentulousPeriodontalPatientCanSucceedIfWeControlTheMainRiskFactorsAndWePlaceThePatientInTheProperSupportiveProgram

TYPEIIObservationalstudies

I declare no conflicts of interest

Figure 3

Axelsson et al 1981

Axelsson’s Paradigm_Infectioncontrol:OHI,extractions,SRP,MWF

_Maintenance:Supra-andsub-gingivaldebridement(2m/2yand3m/3-6)

*Controlgroup:1prophylaxis/year


Heitz-Mayfield, LJ. Peri-implant diseases: diagnosis and risk indicators. J Clin Periodontol 2008 Sep;35(8 Suppl):292–304. doi: 10.1111/j.1600-051X.2008.01275.x.

Heitz-Mayfield LJ, Trombelli L, Heitz F, Needleman I, Moles D. A systematic review of the effect of surgical debridement vs non-surgical debridement for the treatment of chronic periodontitis. J Clin Periodontol. 2002;29 Suppl 3:92–102; discussion 160–2.

Hung HC, Douglas CW. Meta-analysis of the effect of scaling and root planing, surgical treatment and antibiotic therapies on periodontal probing depth and attachment loss. J Clin Periodontol. 2002 Nov;29(11):975–86.

Jepsen S, Stadlinger B, Terheyden H, Sanz M. Science transfer: oral health and general health – the links between periodontitis, atherosclerosis and diabetes. J Clin Periodontol. 2015 Dec;42(12):1071–3. doi: 10.1111/jcpe.12484. Epub 2016 Jan 5.

Matuliene G, Pjetursson BE, Salvi GE, Schmidlin K, Brägger U, Zwahlen M, Lang NP. Influence of residual pockets on progression of periodontitis and tooth loss: results after 11 years of maintenance. J Clin Periodontol. 2008 Aug;35(8):685–95. doi: 10.1111/j.1600-051X.2008.01245.x. Epub 2008 Jul 23.

Monje A, Aranda L, Diaz KT, Alarcón MA, Bagramian RA, Wang HL, Catena A. Impact of Maintenance Therapy for the Prevention of Peri-implant Diseases: A Systematic Review and Meta-analysis. J Dent Res. 2016 Apr;95(4):372–9. doi: 10.1177/0022034515622432. Epub 2015 Dec 23.

Nyman S, Rosling B, Lindhe J. Effect of professional tooth cleaning on healing after periodontal surgery. J Clin Periodontol. 1975 Apr;2(2):80–6.

Nyman S, Lindhe J. A longitudinal study of combined periodontal and prosthetic treatment of patients with advanced periodontal disease. J Periodontol. 1979 Apr;50(4):163–9.

Renvert S, Persson GR. A systematic review on the use of residual probing depth, bleeding on probing and furcation status following initial periodontal therapy to predict further attachment and tooth loss. J Clin Periodontol 2002;29 Suppl 3:82–9; discussion 90–1.

Renvert S, Widén C, Persson GR. Cytokine expression in peri-implant crevicular fluid in relation to bacterial presence. J Clin Periodontol. 2015 Jul;42(7):697–702. doi: 10.1111/jcpe.12422.

Smith MM, Knight ET, Al-Harthi L, Leichter JW. Chronic Periodontitis and Implant Dentistry. Periodontol 2000. 74 (1), 63–73. 6 2017. �




The following report summarises the third paper presented during the The restorative treatment of the partially edentulous periodontitis patient session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

The implant approachTommie Van de VeldeEAO Congress Scientifi c Report; (3), 71–72, 2018.

Scientifi c evidence

The literature clearly supports the use of implants in periodontally compromised patients, although it also shows that these patients are more at risk of peri-implantitis and may have compromised clinical behaviour. Systematic reviews report varying levels of peri-implantitis, with documented prevalence of the disease ranging from 1.7% to 45%. All studies agree, however, that a history of periodontitis is risk factor for peri-implantitis (Figure 1).

These conclusions can be taken as a reference, but we should not automatically presume that the systematic reviews are strictly clinically relevant. There are various additional factors to consider before a clinical decision can be made:

1. ‘Confounding factors’, which infl uence results and may distort conclusions

2. Bias, which is unavoidable in studies, and can affect factors such as: degree of infl ammation, local and anatomical features

3. Time, an important factor in chronic diseases or when comparing teeth to implants; over time, clinical expertise and knowledge also changes and increases

4. Outcome variables, which usually do not include patient acceptance or aesthetic results and sensitivity; time constraints and fi nancial aspects are also common issues involved

Thus, the literature must be counterbalanced with the operator’s clinical experience and the patient’s individual circumstances, needs and preferences.

A patient-centred initial consultation

The speaker listed a number of questions which must fi rst be answered, including: Who is the patient? What is their main complaint? What is their degree of compliance, and for how long do they expect to undergo treatment?

It is also very important to assess how the patient reacts to the initial periodontal treatment. What is clear, however, is that a full resolution of the periodontal disease is a pre-requisite for placing implants. Once all of this has been completed, an individualised treatment plan can be created.

Oral hygiene compliance

According to the consensus report of the European Federation of Periodontology, plaque accumulation is a recognised causative factor for mucositis, and must be controlled as part of the primary prevention of peri-implantitis (Jepsen et al. 2015). The report recommends that implant reconstructions allow proper personal cleaning, diagnosis by probing and professional plaque removal.

Sometimes, the implant approach can offer better chances for keeping the prosthesis free of plaque than conservative and perio-prostho approaches. It may even sometimes be the case that the most reasonable option is to extract all residual teeth and place an implant overdenture (Figure 2).

Figure 1

Dental implants in periodontitis patients• similar implant survival rates • similar supra-structure survival • increased probing depth • increased marginal bone-loss • higher incidence of peri-implantitis • higher incidence of technical and biological complications • outcome might be different • higher risk for implant failure • more implant loss • associated with systemic status • associated with smoking • associated with rehabilitation characteristics • no difference in survival in patients with SPT • no difference between fully-partially edentulism • more pathogenic microflora in partially edentulism • higher incidence without preventive maintenance • higher incidence at sites with inaccessible prosthetics

Figure 2

16

Oral hygiene compliance

perio approach implant approachperio-pros approach


Prosthodontic considerations

A clinical study on partially edentulous patients identifi ed a close correlation between peri-implantitis and accessibility to hygiene (Serino & Ström. 2015). In a recent epidemiological study on 588 patients over nine years it was concluded that poor prosthetic design and margins which were too deep and close to the crestal bone (< 1.5mm) had higher odds for peri-implantitis (Derks et al. 2016).

Therefore the decision to keep a tooth, make a conventional bridge, or extract it and place an implant should be determined by site-specifi c conditions (Figure 3). In the end, the speaker concluded that there is no strict protocol to follow; each case deserves an individualised treatment.

References

Derks J, Schaller D, Håkansson J, Wennström JL, Tomasi C, Berglundh T. Effectiveness of Implant Therapy Analyzed in a Swedish Population: Prevalence of Peri-implantitis. J Dent Res. 2016 Jan;95(1):43–9. doi: 10.1177/0022034515608832.

Jepsen S, Stadlinger B, Terheyden H, Sanz M. Science transfer: oral health and general health – the links between periodontitis, atherosclerosis and diabetes. J Clin Periodontol. 2015 Dec;42(12):1071–3. doi: 10.1111/jcpe.12484. Epub 2016 Jan 5.

Serino G, Turri A, Lang NP. Maintenance therapy in patients following the surgical treatment of peri-implantitis: a 5-year follow-up study. Clin Oral Implants Res. 2015 Aug;26(8):950-6. doi: 10.1111/clr.12418. Epub 2014 May 26. �



Figure 3

19

Site specific conditions

• tooth prognosis • coronal tooth structure • endodontic status • tooth position • strategic prosthodontic position • condition neighbouring teeth • opposing teeth • white aesthetics • pink aesthetics • periodontal support • alveolar bone anatomy • mucosal tissues • accessibility for oral hygiene • …


The following report summarises the fi rst paper presented during the The treatment of peri-implant soft tissue defi ciencies in the anterior maxilla session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

The session chair highlighted the scope of the problem currently posed by peri-implant defi ciencies in the anterior maxilla. He presented a series of questions to the audience which would be addressed by the three speakers:

� patients are demanding long-term outcomes with stable peri-implant tissues. How can we prevent peri-implant tissue defi ciencies?

� recessions around teeth seem to differ in their biological and anatomical characteristics from peri-implant defi ciencies. What are these differences?

� currently, we treat peri-implant defi ciencies and recessions with the same surgical techniques. Is a new surgical approach required?

� can we treat peri-implant defi ciencies with autogenous connective tissue grafts, and if so, which graft would be ideal?

� in some cases, we may need to modify emergence profi les to change the contour of the restoration and facilitate surgical success. Is an interdisciplinary approach the only option for this?

� do we need to modify our surgical approach to achieve more predictable results?

Aesthetic problems with implants in the anterior maxillaMario RoccuzzoEAO Congress Scientifi c Report; (3), 73–74, 2018.

Five factorsThe speaker described fi ve requirements for aesthetic (and inconspicuous) integration of implants into the surrounding tissues (Figure 1):

� intact papillae � convex contour in the buccal aspect � scalloped mucosal margins � natural-looking soft tissue � no mucosal pigmentation

The prevention of soft tissue defi ciencies around implants depends on several morphological factors:

� patient biotype � amount of keratinised tissue available � buccal bone thickness and interproximal

bone levels � correct positioning of the implant with a

suitable diameter � hygienic peri-implant maintenance

The treatment of soft tissue defi ciencies is different in teeth than it is in implants.

To increase the height of peri-implant tissue, width must also be increased. In some cases, one surgical step is enough, but in others two are required. A certain tissue width is required if we want the creeping attachment to cover the margin of the restoration.

Thin soft tissue grafts work well in teeth; in the case of implants, however, wider grafts are required. For this reason, the speaker recommended the use of soft tissue grafts harvested from the tuberosity. This kind of graft can be obtained through a partial thickness fl ap (without releasing incisions) and utilises tissue from the palatal and/or distal areas to create a U-shaped graft (Figure 2).

Figure 1

The treatment of peri-implant soft tissue deficiencies in the anterior maxilla

10 yrs post-op

Inconspicuous implantIntact papillae

Scalloped mucosa

Convex contour buccal aspect

Harmonious soft tissue

No mucosal pigmentation

Figure 2

2

Treatment: CTG maxillary tuberosity

Roccuzzo M, Gaudioso L, Bunino M, Dalmasso P Surgical treatment of buccal soft tissue recessions around single implants: 1-year results from a prospective pilot study.

Clin Oral Implants Res 2014; 25: 641-6


Immediate implants

In complex situations, implant placement should be postponed. A sequenced treatment protocol including GBR and CTG should be adopted.

Although existing evidence supports immediate placement in infected sites (as long as the protocol involves debridement, chlorhexidine irrigation and systemic antibiotics) (Chrcanovic et al. 2015), the speaker stated that he prefers to place immediate implants only when no infection is present. If there is infection, alveolar preservation is his preferred fi rst step for treatment (Figure 3).

Recessions caused by peri-implantitis are diffi cult to treat. The recommended technique involves: cleaning the implant surface thoroughly; grafting the defect with deproteinised bovine bone mineral with 10% collagen (DBBMC); and applying Emdogain® in adjacent tooth surfaces. Usually, no membrane is used. Suffi cient keratinised tissue is necessary.

Conclusion

� the condition of the soft tissue must be considered before starting implant treatment, and the patient must be informed about eventual treatment requirements

� implants should be placed in a periodontally-guided position, meaning that the adjacent teeth should be periodontally healthy and suffi ciently healed following previous augmentation techniques (if they are required) (Figure 4)

� onset of peri-implantitis must be recognised, as its post-treatment behaviour is different from soft tissue defects. In cases involving simple recessions, width can be suffi ciently increased using a CTG and a fl ap without releasing incisions. But when peri-implantitis is present, we must treat it accordingly; in cases where aesthetically displeasing defects have occurred, the implant should be removed (Figure 5)

ReferencesChrcanovic BR, Martins MD, Wennerberg A.

Immediate placement of implants into infected sites: a systematic review. Clin Implant Dent Relat Res. 2015 Jan;17 Suppl 1:e1–e16. doi: 10.1111/cid.12098. Epub 2013 Jul 2. �



Figure 3

Mainconceptspresented Basedon

Implants may be successfully osseointegrated when placed immediately after extraction of teeth presenting endodontic and periodontal lesions

TYPEISYSTEMATICREVIEW

LIMITIMPLANTSINEXTRACTIONSOCKETSTOIDEALSITES TYPEIIIClinicalexperience

Feb 2015 13 y post-opFeb 2002

Figure 4

2. Insert implants in periodontally guided position

Figure 5

Peri-implantitisSoft tissue recession


The following report summarises the second paper presented during the The treatment of peri-implant soft tissue deficiencies in the anterior maxilla session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

The session chair highlighted the scope of the problem currently posed by peri-implant deficiencies in the anterior maxilla. He presented a series of questions to the audience which would be addressed by the three speakers:

� patients are demanding long-term outcomes with stable peri-implant tissues. How can we prevent peri-implant tissue deficiencies?

� recessions around teeth seem to differ in their biological and anatomical characteristics from peri-implant deficiencies. What are these differences?

� currently, we treat peri-implant deficiencies and recessions with the same surgical techniques. Is a new surgical approach required?

� can we treat peri-implant deficiencies with autogenous connective tissue grafts, and if so, which graft would be ideal?

� in some cases, we may need to modify emergence profiles to change the contour of the restoration and facilitate surgical success. Is an interdisciplinary approach the only option for this?


Key variables influencing re-treatment outcomesRino BurkhardtEAO Congress Scientific Report; (3), 75–76, 2018.

A complex problemWe are facing a complex and multifactorial problem. Peri-implant deficiencies can be influenced by a number of patient- and site-related factors, but also by operator- or technique-related factors. It is important to distinguish between these types of complications, because the aetiology of the complication/defect may influence the prognosis.

Operator skills can be categorised as technical or non-technical. The former includes visual-spatial and psychomotor skills; the latter, cognitive social and personal resources. These psychological tools may influence four treatment areas:

� diagnostic ability � treatment plan � technical performance � post-operative care

Decision-making process

Diagnostic errors frequently arise from cognitive bias and/or specific personality traits (Saposnik et al. 2016; Singh et al. 2017). For example, anchoring bias, overconfidence or risk-tolerance are all factors which may influence clinical decisions.

A sound understanding of the nature of errors and how they may occur is a pre-requisite for avoiding or minimising errors. For this reason, we should focus on a strategy which reduces bias (Croskerry P. 2005). Current data indicates that the actual rate of errors is underestimated (Graber ML. 2013). Generally speaking, physicians tend to

overestimate the accuracy of their diagnosis (Berner & Graber. 2008). To ensure an un-biased approach to the clinical reasoning process, ‘cognitive forcing strategies’ have been described (Croskerry P. 2003).

The treatment plan may also be affected by a number of error factors. A coronally displaced mucosal flap with simultaneous connective tissue graft has been shown to be a suitable approach for treating mucosal dehiscences, although complete coverage was not achieved (Burkhardt et al. 2008).

The authors of a recent experimental study comparing the use of a CTG with a collagen matrix in dogs concluded that CTG significantly increased the resistance of the flap to tearing when applying disruptive forces, compared to controls without CTG. The study also found that a less pronounced effect was achieved by the interposition of a collagen matrix (Burkhardt at al. 2016).

When harvesting a palatal graft, a superficial dissection should be made to prevent taking adipose tissue located in the submucosa (3mm deep).

On the other hand, mechanical forces can influence the wound healing process via mechanotransduction in the extracellular matrix and the cytoskeleton of the cell. Forces applied on the macro scale can lead to myofibroblasts growth, fibrous proliferation and tissue contraction during the remodelling phase (Tomasek et al. 2002; Wong et al. 2012). Thus, immobilisation of the graft is crucial for minimising the production of hypertrophic scars and keloids.


Technical performance

An RCT comparing the use of coronally advanced flaps alone and in conjunction with CTG to treat recessions concluded that both procedures were effective, but the adjunctive application of CTG increased the probability of achieving complete root coverage (Cortellini et al. 2009).

Regarding technical performance, the speaker described a recently submitted publication which analyses the influence of visual-spatial and psychomotor abilities in technically demanding surgical interventions. The study classifies these abilities into three groups:

� spatial memory: complex visual-spatial organisation

� psychomotor skills: hand stability and finger dexterity

� surgical performance: this parameter was evaluated by an OSATS test (objective structured assessment of technical skills), according to

‘respect for tissues’, hand motion and economy of movements, and instrument handling

From this, the speaker drew several conclusions:

� surgical performance does not correlate with handedness, nor with self-perceived proficiency

� a high correlation between visual-spatial abilities and surgical performance was found, while there was a low correlation between psychomotor abilities and surgical performance

� these abilities play a different role throughout the learning process

References

Berner ES, Graber ML. Overconfidence as a cause of diagnostic error in medicine. Am J Med 2008 May;121(5 Suppl):S2–23. doi: 10.1016/j.amjmed.2008.01.001.


Burkhardt R, Ruiz Magaz V, Hämmerle CH, Lang NP; Research Group on Oral Soft Tissue Biology & Wound Healing. Interposition of a connective tissue graft or a collagen matrix to enhance wound stability – an experimental study in dogs. J Clin Periodontol. 2016 Apr;43(4):366–73. doi: 10.1111/jcpe.12526. Epub 2016 Mar 29.

Cortellini P, Tonetti MS. Improved wound stability with a modified minimally invasive surgical technique in the regenerative treatment of isolated interdental intrabony defects. J Clin Periodontol. 2009 Feb;36(2):157–63. doi: 10.1111/j.1600-051X.2008.01352.x.

Croskerry P. Cognitive forcing strategies in clinical decisionmaking. Ann Emerg Med. 2003 Jan;41(1):110–20.

Croskerry, P. The theory and practice of clinical decision-making. Can J Anesth 2005 Jun;52(Suppl 1): R1–R8. doi: 10.1007/BF03023077

Graber ML. The incidence of diagnostic error in medicine. BMJ Qual Saf. 2013 Oct;22 Suppl 2:ii21–ii27. doi: 10.1136/bmjqs-2012-001615. Epub 2013 Jun 15.

Saposnik, Redelmeier D, Ruff CC, Tobler PN. Cognitive biases associated with medical decisions: a systematic review. BMC Med Inform Decis Mak. 2016 Nov 3;16(1):138.

Singh H, Schiff GD, Graber ML, Onakpoya I, Thompson MJ. The global burden of diagnostic errors in primary care. BMJ Qual Saf. 2017 Jun;26(6):484–494. doi: 10.1136/bmjqs-2016-005401. Epub 2016 Aug 16.

Tomasek JJ, Gabbiani G, Hinz B, Chaponnier C, Brown RA. Myofibroblasts and mechano-regulation of connective tissue remodelling. Nat Rev Mol Cell Biol. 2002 May;3(5):349-63.

Wong VW, Longaker MT, Gurtner GC. Soft tissue mechanotransduction in wound healing and fibrosis. Semin Cell Dev Biol. 2012 Dec;23(9):981–6. doi: 10.1016/j.semcdb.2012.09.010. Epub 2012 Oct 2. �




The following report summarises the third paper presented during the The treatment of peri-implant soft tissue deficiencies in the anterior maxilla session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.








Presentation of successfully treated clinical casesIon ZabaleguiEAO Congress Scientific Report; (3), 77–78, 2018.

The pathway to successEach aspect of our surgical technique is important. If one step fails, everything fails:

� microsurgery � partial thickness flap � vertical releasing incisions � connective tissue grafts � quality of donor tissue � combined restorative and surgical protocols

(Berroeta et al. 2015)

Results depend not only on surgical protocols, but also on prosthodontics. The treatment of soft tissue deficiencies begins by placing an appropriate prosthesis with thin abutments to leave biological space. Only then can the CTG be performed. One of the limitations in this approach comes from the fact that the abutment cannot be changed for a thinner one (for example, in one-piece implants).

Technique

The best source for harvesting tissue is the lamina propria, located subepithelially. Suturing is also a technique-sensitive step in the surgical procedure: revascularisation occurs better with fewer sutures. The speaker stated that he does not use suspensory sutures, but makes incisions using a sclerotome and prefers to leave a small part of the graft exposed (Figures 1–2). He also recommended using a microsurgical approach, as it can substantially improve the vascularisation of grafts and the percentages of root coverage when compared to the conventional macroscopic approach (Burkhardt & Lang. 2005). The graft should be left for at least three months to heal before recommencing treatment.

Figure 1.1

Figure 1.2

Figure 2


The speaker presented a complex case which was treated with various sequenced connective tissue grafts performed by tunnelling, without raising a flap (Figures 3–4).

Conclusion

Currently, soft tissue augmentation is the preferred treatment option in peri-implant soft tissue deficiencies. This is based mainly on clinical experience (evidence degree III).

References

Berroeta E, Zabalegui I, Donovan T, Chee W. Dynamic Abutment: A method of redirecting screw access for implant-supported restorations: Technical details and a clinical report. J Prosthet Dent. 2015 Jun;113(6):516–9. doi: 10.1016/j.prosdent.2014.11.009. Epub 2015 Mar 18.

Burkhardt R, Lang NP. Coverage of localized gingival recessions: comparison of micro- and macrosurgical techniques. J Clin Periodontol. 2005 Mar;32(3):287–93. �



Figure 3.1

Figure 3.2

Figure 4


The following report summarises the debate which took place during the The treatment of peri-implant soft tissue deficiencies in the anterior maxilla session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.








DebateMario Roccuzzo, Rino Burkhardt and Ion ZabaleguiEAO Congress Scientific Report; (3), 79, 2018.

Why are peri-implant deficiencies more difficult to treat than recessions?This has not been completely investigated in the literature, and only three studies have been carried out to explore this issue (Burkhardt et al. 2008; Zucchelli et al. 2013; Roccuzzo et al. 2014).

It is often the case that implants which have soft tissue deficiencies have been malpositioned. Another consideration is the biological value of the surgical bed, which is much lower in the case of implants.

Are implants a good treatment option in young patients?In young patients, there is residual growth of teeth and surrounding tissues. It is yet to be fully understood how this growth will affect or be affected by implant restorations, which remain unchanged. For this reason, an adhesive pontic could be a good option for a young patient.

Where should we harvest connective tissue for grafts?The speakers each had different preferences. Roccuzzo recommended the tuberosity, due to its higher density. Zabalegui stated that he generally harvests tissue from the palatal surface, although he also harvests from the tuberosity if it is available. Burkhardt emphasised that there is insufficient evidence. He conceded that the tissue from the

tuberosity is denser and has more volume, but mentioned that fibrosis is more likely to be provoked from tuberosity tissue. A thinner graft is needed in teeth, but in implants the tissue from the tuberosity could be more convenient.

Is training an issue in surgical performance?Burkhardt suggested that clinicians should train themselves specifically with adequate models. Surgical performance may improve with practice.

References


Roccuzzo M, Gaudioso L, Bunino M, Dalmasso P. Surgical treatment of buccal soft tissue recessions around single implants: 1-year results from a prospective pilot study. Clin Oral Implants Res. 2014 Jun;25(6):641–6. doi: 10.1111/clr.12149. Epub 2013 Apr 15.

Zucchelli G, Mazzotti C, Mounssif I, Mele M, Stefanini M, Montebugnoli L. A novel surgical-prosthetic approach for soft tissue dehiscence coverage around single implant. Clin Oral Implants Res. 2013 Sep;24(9):957–62. doi: 10.1111/clr.12003. Epub 2012 Aug 27. �




The following report summarises the first paper presented during the Liaison for the best patient service. Materials of choice for anterior restorations? session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Implant restorations combine biological and technical issues which are similar to and yet different from those associated with tooth restorations. There are a number of specific factors which play an important role in implant restorations such as: implant position; design, shape, material and colour of the selected abutment; prosthetic design; and the effect of the restorative components on surrounding tissues.

There are three basic types of materials used in anterior restorations: disilicate, zirconium and metal porcelain. The question is: how important is the material in the overall treatment process? And which of the three materials can offer the best tissue integration in the aesthetic area?

The clinical use of zirconia in restorations in the anterior regionGuillermo Pradíes and Javier PérezEAO Congress Scientific Report; (3), 80–82, 2018.

Classification and termsNowadays, a good and practical classification of all ceramic systems could be: silicate ceramics, oxide ceramics and hybrid materials.

The behaviour of ceramic materials can be briefly summarised as follows: the higher the crystalline phase in the ceramic composition, the more strength it has; the greater the vitreous phase, the better its aesthetics are likely to be. An intermediary balanced ceramic composition is therefore needed (Figures 1–2).

When describing the material, we use the word ‘zirconium’. However, this is often too vague, and additional information is required (Figure 3). The phase of zirconia is dependent on the temperature. Tetragonal zirconia is the most common, and can be stabilised by yttria. This is known as yttria-stabilised tetragonal zirconia polycrystal (Y-TZP). Its strength is due to the properties of zirconia which allow it to close microcracks by the material transition to the monoclinic phase.

The clinical performance of zirconia was demonstrated by a comparison with metal-ceramic restorations (Suárez et al. 2004). Concerns about the aging process of zirconia had also been raised in the field of orthopaedics (Chevalier J. 2006). Later, a prospective clinical study reported that the survival rate of four-unit posterior zirconia bridges was only 76.5% after a four-year follow-up (Salido et al. 2012).

Zirconia abutments

To ensure long-term stability, a minimum thickness of 0.8mm is required in the entire structure of the zirconia abutment (Martínez-Rus et al. 2014). In a comparative in vitro study on a sample of 20 titanium and 20 zirconia abutments, the highest fracture resistance was achieved with titanium abutments restored with monolithic lithium disilicate crowns (Martínez-Rus et al. 2012).

Figure 1

Figure 3

Figure 2


Figure 4

Figure 5

Some major disadvantages have been associated with pre-contoured zirconia abutments: they do not easily accommodate modifications or direct ceramic application over them. Furthermore, when they are directly connected to implants, they are susceptible to wear, damage and fatigue. To resolve this, some manufacturers have added a titanium base to zirconia abutments, which ensures lower levels of friction fractures.

According to the speaker, a good option for preventing mechanical failures would be to use a biologically oriented preparation technique (BOPT) with margin-less preparation of teeth and titanium abutments and cemented zirconia crowns. Aesthetic results associated with this approach are not always optimal, however it should be noted that they can be better with a margin-less preparation than with the standard margin preparation.

Could the aesthetics be improved? A recent clinical study evaluated the optical interference of subjacent abutment materials with their aesthetic appearance at coronal and soft tissue margin levels. The study concluded that although the lowest optical values were measured on zirconia abutments in terms of Delta E, they were still above the acceptable value (Martínez-Rus et al. 2017).

The evolution

In a retrospective survey of comparative long-term results of zirconia-veneered and metal-ceramic crowns on natural teeth in the posterior area, no significant differences between the crown types were reported (Ozer et al. 2014). Currently, zirconia structures are designed with a uniform thickness and an underlying shape which makes them more resistant to fractures. Indeed, the anatomical design of the abutment supporting the zirconia crown decreases chipping dramatically (Sundh & Sjögren. 2004; Silva et al. 2012).

In addition to the design, chipping can also be caused by features of the manufacturing processes. Sudden changes in temperature during this process encourage the formation of micro-bubbles which can lead to fractures in future. It is important to control shrinkage and the corresponding stress between the periphery and core of zirconia through slower heating/cooling cycles (Pascual et al. 2001).

Monolithic zirconia

Chipping does not occur in monolithic zirconia restorations, provided a proper anatomical design has been applied.

The need for occlusal adjustments should be minimised, as the surface should be altered as little as possible. If the zirconia restoration was ground, it must be polished in the lab, or even heated to cause a reverse transformation (from monoclinic to tetragonal) (Denry & Kelly. 2008).

Regarding its impact on the antagonist teeth, zirconia is much less abrasive and causes less wear

on the opposing teeth than feldspathic porcelain (Hmaidouch et al. 2014).

Aesthetics are a significant concern in monolithic zirconia, as it lacks translucency and natural appearance. To overcome this, a buccally thin veneering technique has been proposed using a lithium disilicate ceramic laminate which does not encroach into functional areas (Figures 4–5).

Another method for improving aesthetics is to use a hybrid abutment by cementing zirconia to mechanical interfaces on titanium. This approach attempts to harness the advantages of both materials: the mechanical stability of titanium and the aesthetic appearance of zirconia (Carvalho et al. 2014). Needless to say, a strict adhesion protocol must be followed.

The submucosal zirconia should be polished to a surface roughness of Ra=0.2μm. This roughness helps attachment gain as it has better cellular proliferation rates than highly polished surfaces (of Ra=0.05 μm) (Mustafa et al. 2008, Happe & Körner. 2011; Happe et al. 2015). No stain or glazes are applied where the surface is in contact with soft tissues.

Translucent zirconia

There is one more step in the race for improving the aesthetics of zirconia. The ability to pass light thorough zirconia structures is related to its particle and grain size (the smaller the better); density (absence of pores); and crystalline microstructure.

In general, an inverse relationship between strength and translucency has been shown. These two properties are heavily influenced by the sintering process and the percentages of yttria and alumina in the ceramic composition. By modifying these factors during the manufacturing process, new materials with intermediate properties between conventional zirconia and lithium disilicate can be obtained (Carrabba et al. 2017).


Take-home messages

� the word ‘zirconia’ is not enough � a titanium interface is highly recommended to

connect zirconia abutments to implants � the low-temperature aging process is still not

fully understood � the clinical and laboratory management of

zirconia are both crucial � changes to the optical properties of zirconia also

affect mechanical behaviour � monolithic translucent zirconia with an aesthetic

laminate is ready for use � in the aesthetic zone, there are options beyond

zirconia (Figure 6)

References

Bonfante EA, da Silva NR, Coelho PG, Bayardo-González DE, Thompson VP, Bonfante G. Effect of framework design on crown failure. Eur J Oral Sci. 2009 Apr;117(2):194–9. doi: 10.1111/j.1600-0722.2008.00608.x.

Carrabba M, Keeling AJ, Aziz A, Vichi A, Fabian Fonzar R, Wood D, Ferrari M. Translucent zirconia in the ceramic scenario for monolithic restorations: A flexural strength and translucency comparison test. J Dent. 2017 May;60:70–76. doi: 10.1016/j.jdent.2017.03.002. Epub 2017 Mar 6.

Carvalho MA, Sotto-Maior BS, Del Bel Cury AA, Pessanha Henriques GE. Effect of platform connection and abutment material on stress distribution in single anterior implant-supported restorations: a nonlinear 3-dimensional finite element analysis. J Prosthet Dent. 2014 Nov;112(5):1096–102.

Chevalier J. What future for zirconia as a biomaterial? Biomaterials. 2006 Feb;27(4):535–43. Epub 2005 Sep 6.

Denry I, Kelly JR. State of the art of zirconia for dental applications. Dent Mater. 2008 Mar;24(3):299–307. Epub 2007 Jul 19.

Happe A, Körner G. Biologic Interfaces in esthetic dentistry. Part II: the peri-implant/restorative interface. Eur J Esthet Dent. 2011 Summer;6(2):226–51.

Happe A, Röling N, Schäfer A, Rothamel D. Effects of different polishing protocols on the surface roughness of Y-TZP surfaces used for custom-made implant abutments: a controlled morphologic SEM and profilometric pilot study. J Prosthet Dent. 2015 May;113(5):440–7.

Martínez-Rus F, Ferreiroa A, Özcan M, Bartolomé JF, Pradíes G. Fracture resistance of crowns cemented on titanium and zirconia implant abutments: a comparison of monolithic versus manually veneered all-ceramic systems. Int J Oral Maxillofac Implants. 2012 Nov–Dec;27(6):1448–55.

Martínez-Rus F, Rivera B, Özcan M, Pradíes G. Prosthodontic considerations in the implant-supported all-ceramic restoration of congenitally missing maxillary lateral incisor: a clinical report. J Prosthodont. 2014 Apr;23(3):232–5. doi: 10.1111/jopr.12096. Epub 2013 Oct 7.

Martínez-Rus F, Prieto M, Salido MP, Madrigal C, Özcan M, Pradíes G. A Clinical Study Assessing the Influence of Anodized Titanium and Zirconium Dioxide Abutments and Peri-implant Soft Tissue Thickness on the Optical Outcome of Implant-Supported Lithium Disilicate Single Crowns. Int J Oral Maxillofac Implants. 2017 Jan/Feb;32(1):156–163. doi: 10.11607/jomi.5258.

Mustafa K, Wennerberg A, Arvidson K, Messelt EB, Haag P, Karlsson S. Influence of modifying and veneering the surface of ceramic abutments on cellular attachment and proliferation. Clin Oral Implants Res. 2008 Nov;19(11):1178–87. doi: 10.1111/j.1600-0501.2008.01560.x.

Ozer F, Mante FK, Chiche G, Saleh N, Takeichi T, Blatz MB. A retrospective survey on long-term survival of posterior zirconia and porcelain-fused-to-metal crowns in private practice. Quintessence Int. 2014 Jan;45(1):31–8. doi: 10.3290/j.qi.a30768.

Salido MP, Martinez-Rus F, del Rio F, Pradies G, Ozcan M, Suarez MJ. Prospective clinical study of zirconia-based posterior four-unit fixed dental prostheses: four-year follow-up. Int J Prosthodont. 2012 Jul–Aug;25(4):403–9.

Silva NR, Bonfante E, Rafferty BT, Zavanelli RA, Martins LL, Rekow ED, Thompson VP, Coehlo PG. Conventional and modified veneered zirconia vs. metalloceramic: fatigue and finite element analysis. J Prosthodont. 2012 Aug;21(6):433–9. doi: 10.1111/j.1532-849X.2012.00861.x. Epub 2012 Jun 1.

Suárez MJ, Lozano JF, Paz Salido M, Martínez F. Three-year clinical evaluation of In-Ceram Zirconia posterior FPDs. Int J Prosthodont. 2004 Jan–Feb;17(1):35–8.

Sundh A, Sjögren G. A comparison of fracture strength of yttrium-oxide- partially-stabilized zirconia ceramic crowns with varying core thickness, shapes and veneer ceramics. J Oral Rehab 2004 Jul;31(7):682–8.

Tinschert J, Schulze KA, Natt G, Latzke P, Heussen N, Spiekermann H. Clinical behavior of zirconia-based fixed partial dentures made of DC-Zirkon: 3-year results. Int J Prosthodont. 2008 May–Jun;21(3):217–22.

Pascual MJ, Pascual L, Dura’n A. Determination of the Viscosity-Temperature Curve for Glasses on the Basis of Fixed Viscosity Points Determined by Hot Stage Microscopy. Phys Chem Glasses 2001 Feb;42(1):61–66. �



Figure 6


The following report summarises the second paper presented during the Liaison for the best patient service. Materials of choice for anterior restorations? session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

Implant restorations combine biological and technical issues which are similar to and yet different from those associated with tooth restorations. There are a number of specifi c factors which play an important role in implant restorations such as: implant position; design, shape, material and colour of the selected abutment; prosthetic design; and the effect of the restorative components on surrounding tissues.

There are three basic types of materials used in anterior restorations: disilicate, zirconium and metal porcelain. The question is: how important is the material in the overall treatment process? And which of the three materials can offer the best tissue integration in the aesthetic area?

Alternatives to zirconia restorations in the anterior regionVincent Fehmer and Daniel S. ThomaEAO Congress Scientifi c Report; (3), 83–84, 2018.

Although the use of zirconia is currently considered standard in the aesthetic area, the decision to use it should be made with the patient in mind, as well as the clinician and technician. Patients expect healthy, functional, aesthetic and long-term restorations. To meet these expectations, practitioners must consider the materials and various requirements of the laboratory and dentist.

The clinician’s perspective

The colour of peri-implant soft tissues matches that of the contralateral tooth in only a third of cases. The peri-implant mucosa often shows visible discolouration, and the determining factor is the mucosal thickness (Fürhauser et al. 2005; Sailer et al. 2014). Soft tissue thickness can be augmented by a connective tissue graft, thereby improving aesthetics and decreasing levels of marginal bone loss.

A randomised controlled trial carried out in 2007 compared optical outcomes in the aesthetic area of a group of patients with metal-ceramic crowns to another group treated with ceramic abutments and ceramic crowns. The results were statistically signifi cant, especially when a thin mucosa was present and no soft tissue grafting was performed. Soft tissue thickness is therefore a critical factor; if there is enough marginal thickness available, the choice of material is irrelevant from an aesthetic point of view (Jung et al. 2007; Jung et al. 2008).

The technician’s perspective

The technician’s perspective is based on the optical properties of materials when light goes through them (Figure 1).

It should, however, be taken into account that although ceramics have better aesthetics, they are signifi cantly weaker than metals. The selection of materials should be based in part on aesthetic aspects (for instance, the brightness value or

translucency of the neighbouring teeth), and in part on the available inter-occlusal space and clinical evidence from survival rates (Fehmer et al. 2014). The speakers emphasised that the selection of reconstructive materials is not a subjective process, and clinicians should follow clear guidelines based on these factors (Figures 2–5).

Material strength

As abutment materials, ceramics are limited by their brittleness. The most resistant ceramic is zirconia, however it is still much weaker than titanium. Other ceramic abutments have been tested, but have been found to be too fragile in vitro (Yildirim et al. 2003; Leutert et al. 2012). Zirconia abutments with a titanium interface supporting monolithic zirconia crowns currently have the best mechanical performance. Laboratory tests have shown titanium bases bending under a 30º angulated static loading

Figure 1

2


(ISO 14801), instead of fracturing the abutments, which is what happens when no metal base has been interposed (Sailer et al. 2017 submitted).

Back to the clinic again

Regarding materials, the speakers discussed various systematic reviews of abutments, single crowns, and fi xed dental prostheses on implants (Sailer et al. 2009; Jung et al. 2012; Pjetursson et al. 2012). The fi ve-year survival rates of metal abutments and zirconia abutments seem similar; however the comparative rates of metal-ceramic and all-ceramic restorations were 35x higher (at the level of abutment), 8x higher (level of crown) and 50x higher (level of multi-unit fi xed partial prostheses). It should also be noted that ten-year results are only available for metal-ceramic prostheses.

Having summarised the clinical evidence, metal-ceramic reconstructions should be considered the current standard. There are no contraindications for their use in single- and multi-unit reconstructions. The only concern to be considered would be a thin biotype in the aesthetic region.

Another interesting indication for metal-ceramics is in combination with tooth-supported restorations in complex cases, and even in cases where cantilevers are present. In the case of the latter, there is currently no evidence of the clinical use of cantilevers other than with metal-ceramic restorations.

Although they have not yet been suffi ciently documented, hybrid abutment confi gurations with a titanium base and zirconia cemented onto it are widely used for partial fi xed prostheses as well as single restorations.

References

Fehmer V, Mühlemann S, Hämmerle CH, Sailer I. Criteria for the selection of restoration materials. Quintessence Int. 2014 Oct;45(9):723–30.

Fürhauser R, Florescu D, Benesch T, Haas R, Mailath G, Watzek G. Evaluation of soft tissue around single-tooth implant crowns: the pink esthetic score. Clin Oral Implants Res. 2005 Dec;16(6):639–44.

Jung RE, Sailer I, Hämmerle CH, Attin T, Schmidlin P. In vitro color changes of soft tissues caused by restorative materials. Int J Periodontics Restorative Dent. 2007 Jun;27(3):251–7.

Jung RE, Holderegger C, Sailer I, Khraisat A, Suter A, Hämmerle CH. The effect of all-ceramic and porcelain-fused-to-metal restorations on marginal peri-implant soft tissue color: a randomized controlled clinical trial. Int J Periodontics Restorative Dent. 2008 Aug;28(4):357–65.

Jung RE, Zembic A, Pjetursson BE, Zwahlen M, Thoma DS. Systematic review of the survival rate and the incidence of biological, technical, and aesthetic complications of single crowns on implants reported in longitudinal studies with a mean follow-up of 5 years. Clin Oral Implants Res. 2012 Oct;23 Suppl 6:2–21.

Leutert CR, Stawarczyk B, Truninger TC, Hämmerle CH, Sailer I. Bending moments and types of failure of zirconia and titanium abutments with internal implant-abutment connections: a laboratory study. Int J Oral Maxillofac Implants. 2012 May–Jun;27(3):505–12.

Pjetursson BE, Thoma D, Jung R, Zwahlen M, Zembic A. A systematic review of the survival and complication rates of implant-supported fi xed dental prostheses (FDPs) after a mean observation period of at least 5 years. Clin Oral Implants Res. 2012 Oct;23 Suppl 6:22–38.

Sailer I, Fehmer V, Ioannidis A, Hämmerle CH, Thoma DS. Threshold value for the perception of color changes of human gingiva. Int J Periodontics Restorative Dent. 2014 Nov–Dec;34(6):757–62. doi: 10.11607/prd.2174.

Sailer I, Philipp A, Zembic A, Pjetursson BE, Hämmerle CH, Zwahlen M. A systematic review of the performance of ceramic and metal implant abutments supporting fi xed implant reconstructions. Clin Oral Implants Res. 2009 Sep;20 Suppl 4:4–31. doi: 10.1111/j.1600-0501.2009.01787.x.

Yildirim M, Fischer H, Marx R, Edelhoff D. In vivo fracture resistance of implant-supported all-ceramic restorations. J Prosthet Dent. 2003 Oct;90(4):325–31. �

This summary was prepared by the EAO Congress Scientifi c Report rapporteurs and approved by the speakers.


2 3

4


The following report summarises the fi rst paper presented during the Alternatives to titanium as an implant material and custom-made implants session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

This session explored possible alternatives for implant materials in order to understand the latest developments and discern whether they can be considered viable alternatives for titanium in clinical practice.

PEEK implants: ready for clinical use?Pär JohanssonEAO Congress Scientifi c Report; (3), 85–86, 2018.

Polyetheretherkeratone (PEEK) has been used with increasing regularity as a biomaterial for treating trauma and orthopaedic cases, as well as in spinal implants. PEEK’s inertness and low elastic modulus have made it suitable for implants being placed close to the bone (Kurtz et al. 2007). In the dental fi eld, it is known for its numerous applications – mainly to make provisional prostheses and abutments.

PEEK surfaces are bioinert and hydrophobic, qualities which help minimise microbiological proliferation; however, unmodifi ed PEEK surfaces do not have any properties which enable osseointegration (Rabiei et al. 2013). Bone/implant contact levels achieved by PEEK implants are signifi cantly lower than those of titanium (Nakahara et al. 2012; Webster et al. 2012; Wu et al. 2013) and need to be improved. This can be done by increasing the bioactivity of PEEK.

PEEK surfaces

In various attempts to modify its biological properties, PEEK has been used as a platform for developing novel bioactive composite materials. However, any modifi cations to its biological properties should not affect the properties of the core material. This is because, to date, blended HA/PEEK composites have involved a trade-off, where mechanical behaviour is exchanged for enhanced bioactivity.

The latest research has focused on surface modifi cations. Physical or chemical modifi cations aim to change the topography of the material by increasing surface area and improving wettability. These methods involve applying bioactive coatings like HA and TCP (or even TiO2) to the surface of sintered PEEK (Han et al. 2009; Lee et al. 2013).

However, it is well known that thick coatings are at risk of delamination. Spin coating has been used to deposit extremely thin layers (20–40 nm) of nano-HA. This technique does not affect the underlying roughness on the micro level, but increases osseo-conductivity and bone/implant contact levels. Additionally, removal torque was signifi cantly improved in a rabbit model. These effects of spin coating were more prominent at

three weeks, during the early phases of bone formation; at twelve weeks, the differences almost disappeared (Johansson et al. 2014 and 2016; Johansson et al. 2015).

PEEK biomechanical properties

Titanium is eight times more rigid than bone. In contrast, PEEK can be designed and reinforced with carbon-fi bres to have a similar elastic modulus to cortical bone, thus drastically reducing the risk of stress shielding. A recent study had controversial fi ndings, reporting that no biomechanical advantages were demonstrated in polymer implants when compared to titanium, in a fi nite element analysis (Korabi et al. 2017). Optimal stiffness levels are yet to be defi ned. The speaker suggested that perhaps optimal biomechanics could be achieved if stiff implants are used during the healing phase, and fl exible implants during the loading phase.

Conclusions

Experimental research (type III) has shown that:

� unmodifi ed PEEK is unsuitable to be used as an implant material

� PEEK’s bioactivity can be improved with bioceramic coatings

� to date, the optimal implant stiffness remains undefi ned

Figure 1


Unmodified PEEK is unsuitable as a dental implant material Experimental research

The bioactivity of PEEK can be improved with incorporation or coating of bioceramics

Experimental research

The optimal stiffness of dental implants remains undefined due to contradictory research outcomes

Experimental research


References

Han Y, Yan Y, Lu C, Zhang Y, Xu K. Bioactivity and osteoblast response of the micro-arc oxidized zirconia films. J Biomed Mater Res A. 2009 Jan;88(1):117–27. doi: 10.1002/jbm.a.31859.

Johansson P, Jimbo R, Kjellin P, Currie F, Chrcanovic BR, Wennerberg A. Biomechanical evaluation and surface characterization of a nano-modified surface on PEEK implants: a study in the rabbit tibia. Int J Nanomedicine. 2014 Aug 14;9:3903–11. doi: 10.2147/IJN.S60387. eCollection 2014.

Johansson P, Jimbo R, Kozai Y, Sakurai T, Kjellin P, Currie F, Wennerberg A. Nanosized Hydroxyapatite Coating on PEEK Implants Enhances Early Bone Formation: A Histological and Three-Dimensional Investigation in Rabbit Bone. Materials (Basel). 2015 Jun 25;8(7):3815–3830. doi: 10.3390/ma8073815.

Johansson P, Jimbo R, Naito Y, Kjellin P, Currie F, Wennerberg A. Polyether ether ketone implants achieve increased bone fusion when coated with nano-sized hydroxyapatite: a histomorphometric study in rabbit bone. Int J Nanomedicine. 2016 Apr 6;11:1435–42. doi: 10.2147/IJN.S100424. eCollection 2016.

Korabi R, Shemtov-Yona K, Rittel D. On stress/strain shielding and the material stiffness paradigm for dental implants. Clin Implant Dent Relat Res. 2017 Oct;19(5):935–943. doi: 10.1111/cid.12509. Epub 2017 Jun 13.

Kurtz SM1, Devine JN. PEEK biomaterials in trauma, orthopedic, and spinal implants. Biomaterials 2007 Nov;28(32):4845–69. Epub 2007 Aug 7.

Lee JE, Park S, Park M, Kim MH, Park CG, Lee SH, Choi SY, Kim BH, Park HJ, Park JH, Heo CY, Choy YB. Surgical suture assembled with polymeric drug-delivery sheet for sustained, local pain relief. Acta Biomater. 2013 Sep;9(9):8318–27. doi: 10.1016/j.actbio.2013.06.003. Epub 2013 Jun 14.

Nakahara I, Takao M, Goto T, Ohtsuki C, Hibino S, Sugano N. Interfacial shear strength of bioactive-coated carbon fiber reinforced polyetheretherketone after in vivo implantation. J Orthop Res. 2012 Oct;30(10):1618–25. doi: 10.1002/jor.22115. Epub 2012 Mar 30.

Rabiei A, Sandukas S. Processing and evaluation of bioactive coatings on polymeric implants. J Biomed Mater Res A. 2013 Sep;101(9):2621–9. doi: 10.1002/jbm.a.34557. Epub 2013 Feb 15.

Webster TJ, Patel AA, Rahaman MN, Sonny Bal B. Anti-infective and osteointegration properties of silicon nitride, poly(ether ether ketone), and titanium implants. Acta Biomater. 2012 Dec;8(12):4447–54. doi: 10.1016/j.actbio.2012.07.038. Epub 2012 Jul 31.

Wu SH, Li Y, Zhang YQ, Li XK, Yuan CF, Hao YL, Zhang ZY, Guo Z. Porous titanium-6 aluminum-4 vanadium cage has better osseointegration and less micromotion than a poly-ether-ether-ketone cage in sheep vertebral fusion. Artif Organs. 2013 Dec;37(12):E191–201. doi: 10.1111/aor.12153. Epub 2013 Oct 22. �




The following report summarises the second paper presented during the Alternatives to titanium as an implant material and custom-made implants session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.


Ceramic implants a real alternative to titanium today? Part I: material aspectsChristel LarssonEAO Congress Scientific Report; (3), 87–88, 2018.

There is a strong evidence-base supporting the use of titanium in implants. However, there are a number of reasons for using ceramic implants:

� aesthetics: in cases involving a receding or thin mucosa, ceramic implants can match the colour of natural teeth much better than titanium

� immune response: instances of titanium allergies have been reported in the literature

� peri-implant tissue response: ceramic surfaces are less prone to bacterial adhesion

� galvanic side effects: theoretical possibility in metals

� patient preference: some patients favour ceramics over metals

The speaker then described the differences in atomic bonding and molecular structure between metals and ceramics which influence their mechanical behaviour under loading. Metals show high strength and resistance to stress and deformation. Ceramics show high stiffness but lower resistance to tensile stress and deformation as they are brittle materials. The brittleness of zirconia-based ceramic materials that are used for implants can be offset by their unique ability for phase transformation toughening. This process strengthens the ceramic and reduces risks of fracture.

Strong covalent atomic bonds make ceramics less prone to interactions with its environment which may be advantageous in reducing risks of negative host response.

The speaker then presented five hypotheses, to explore whether this toughening mechanism is enough to offset mechanical implant failure.

Hypothesis 1: Higher risk of implant fracture due to less strength?The brittleness and lower resistance to deformation of zirconia implants may lead to an increased risk of mechanical failure (such as fracture).

Hypothesis 2: Higher risk of mechanical implant failure due to fatigue?Mechanical (cyclic loading) and chemical factors (moisture) cause degradation of the implant material at low loads. Defects may act as crack initiation sites. Ceramic materials are less able to adapt to crack formation and may be at higher risk of fatigue failure.

Hypothesis 3: No significant differences in osseointegration?Titanium and zirconia implants have similar chemical (oxide layers) and physical (moderately rough surface topography) surface characteristics and are likely to show equal potential for osseointegration (Hafezeqoran et al. 2017; Bauer et al. 2013).

Hypothesis 4: Lower risk of peri-implant disease?In vitro tests suggest that zirconia shows less biofilm formation and bacterial adhesion than titanium (Roehling et al. 2017).This is attributed to differences in hydrophobicity, reduced surface energy and wettability. The inflammatory response has also been reported to be reduced although an explanatory model is lacking. There may be a possibility of fewer instances of peri-implant disease at zirconia implants.

Hypothesis 5: Lower risk of adverse immune response?Although a passive oxide layer of TiO2 is formed on the surface of titanium implants, mimicking the chemical properties of the inert ceramic implants, some release of Ti ions occurs, which has been suggested to be associated with allergic responses (Tschernitschek et al. 2005).


References

Bauer S, Schmuki P, von der Mark K, Park J. Engingeering biocompatible implant surfaces. Part I: Materials and surfaces. Progress in Materials Science 2013 Apr; 58(3):261–326.

Hafezeqoran A, Koodaryan R. Effect of Zirconia Dental Implant Surfaces on Bone Integration: A Systematic Review and Meta-Analysis. Biomed Res Int. 2017;2017:9246721. doi: 10.1155/2017/9246721. Epub 2017 Feb 16.

Roehling S, Astasov-Frauenhoffer M, Hauser-Gerspach I, Braissant O, Woelfler H, Waltimo T, Kniha H, Gahlert M. In Vitro Biofilm Formation on Titanium and Zirconia Implant Surfaces. J Periodontol. 2017 Mar;88(3):298–307. doi: 10.1902/jop.2016.160245. Epub 2016 Oct 7.

Tschernitschek H, Borchers L, Geurtsen W. Nonalloyed titanium as a bioinert metal--a review. Quintessence Int. 2005 Jul–Aug;36(7-8):523–30. �




The following report summarises the third paper presented during the Alternatives to titanium as an implant material and custom-made implants session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.


Ceramic implants as a real alternative to titanium today? Part II: clinical outcomesRalf KohalEAO Congress Scientific Report; (3), 89, 2018.

Ceramic implants are a treatment option which seems to be preferred by many patients. This is due to: lower associated risk of allergic response; better aesthetics; lower susceptibility to corrosion; no metallic ion release; better tissue acceptance; lower rates of biofilm adherence; and the trend towards holistic medicine.

The biocompatibility of zirconia has been well documented both in cell culture tests and in multiple animal experiments (Kohal et al. 2004). Titanium-like levels of osseointegration have been repeatedly confirmed in terms of bone/implant contact and removal torque tests (da Silva et al. 2010; Manzano et al. 2014; Pieralli et al. 2017). We can therefore conclude that modified-surface zirconia may be considered a potential alternative for implant materials; however, further clinical studies are required.

Regarding the stability of zirconia implants, laboratory investigations reported in the current literature conclude that one-piece ceramic implants are able to withstand chewing forces, and two-piece implants are rapidly improving.

There are numerous reports concerning the clinical applications and success rates of ceramic implants. As an example of the recent increase in demand for ceramics, the speaker showed a number of implant brands and systems, some of them already withdrawn from sale.

Scientific data on ceramic implants is also a growing (although incomplete) field. Authors of a recent systematic review concluded that the short-term cumulative survival rates and the marginal bone loss around zirconia implants (for single -tooth replacements or small fixed dental prostheses) are promising, although additional data is still needed to confirm long-term predictability (Pieralli et al. 2017).

The speaker then revisited the five hypotheses put forward by the previous speaker, and replied to each one:

Hypothesis 1: Higher risk of implant fracture due to less strength: Not been demonstrated

Hypothesis 2: Higher risk of mechanical implant failure due to fatigue: Not been demonstrated

Hypothesis 3: No significant differences in osseointegration: Yes

Hypothesis 4: Lower risk of peri-implant disease: No data

Hypothesis 5: Lower risk of adverse immune response: Hopefully

References

da Silva WJ, Seneviratne J, Samaranayake LP, Del Bel Cury AA. Bioactivity and architecture of Candida albicans biofilms developed on poly(methyl methacrylate) resin surface. J Biomed Mater Res B Appl Biomater. 2010 Jul;94(1):149–56.

Kohal RJ, Weng D, Bächle M, Strub JR. Loaded custom-made zirconia and titanium implants show similar osseointegration: an animal experiment. J Periodontol. 2004 Sep;75(9):1262–8.

Manzano G, Herrero LR, Montero J. Comparison of clinical performance of zirconia implants and titanium implants in animal models: a systematic review. Int J Oral Maxillofac Implants. 2014 Mar–Apr;29(2):311–20. doi: 10.11607/jomi.2817.

Pieralli S, Kohal RJ, Jung RE, Vach K, Spies BC. Clinical Outcomes of Zirconia Dental Implants: A Systematic Review. J Dent Res. 2017 Jan;96(1):38–46. doi: 10.1177/0022034516664043. Epub 2016 Oct 1. �




The following report summarises the fourth paper presented during the Alternatives to titanium as an implant material and custom-made implants session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.


Are custom-made implants ready for clinical use?Daniel WismeijerEAO Congress Scientifi c Report; (3), 90–91, 2018.

When discussing custom-made implants, we are faced with a ‘disruptive innovation’. This kind of innovation creates a new market and value network, ultimately disrupting the existing market and network, and displaces established market leaders and alliances (Bower & Christensen. 1995). The speaker described how disruptive innovation has a ‘signifi cant societal impact’ (Huang et al. 2013) (Figure 1)

Custom implants can be made of metals, polymers or ceramics. They can be printed in a controlled additive layer manufacturing (ALM) atmosphere (with neutral gasses and restricted oxygen) insuring high purity of material.

Digitalisation and 3D-printing have created a paradigm-shift in dentistry. Crown and bridgework can be 3D printed in resin restorations either as temporary or fi nal restorations that can stay in the mouth for an indefi nite period (Figure 2).

3D printed implants can be printed in titanium (Figure 3) and today, it is possible to print zirconia (if shrinkage during thermal sintering is taken into account) (Figure 4).

With customised implants, fewer adjustments and fewer bone preparation or augmentation procedures are required during surgery. This means: shorter surgery times and less follow-up surgery. The problems with this technology, however, arise from uncertainty surrounding regulations, certifi cation, and design ownership.

Based on the CBCT data, a replica of the tooth root to be extracted can be prepared as an implant tailored to the specifi c needs of the patient (Figure 5). Through a similar digital workfl ow, customised bone substitutes which fi t the individual patient’s anatomy can be also printed.

Figure 1

Disruptive innovation An innovation that creates a new market and value network and eventually disrupts an existing market and value network, displacing established market leaders and alliances. The term was defined and the phenomenon analyzed in 1995.

More recent sources also include "significant societal impact" as an aspect of disruptive innovation (2013) Bower, J. L., and C. M. Christensen.

"Disruptive Technologies: Catching the Wave."

Harvard Business Review 73, no. 1 (January–February 1995): 43–53. S.A.Huang, P.Liu, A.Mokasdar,L.Hou.

Additive manufacturing and it’s societal impact: a literature review

Int J Advanced Technology July 2013, 67;5:1191-1203

Figure 3

Digitalization. Custom-made Dental Implants

Figure 4


Figure 2

Effects of build direction on the mechanical properties of 3D-printed complete coverage interim dental restorations Nawal Alharbi · Reham Osman · Daniel Wismeijer J Prosth Dent 2016

3D printing in dentistry


Medical devices are now the subject of a recent European Union regulation: 2017/745 (Figure 6). The regulation extends to the whole supply chain: from device and software manufacturers, to the cloud provider, the treatment provider and fi nally the patient. As stated in the regulation and quoted

as follows in article 10: ‘Manufactures of custom made medical devices shall draw up and keep up to date and keep available for competent authorities documentation in accordance with Section 2 of Annex XIII.’ This means that anyone that produces a custom made medical device will be seen as a manufacturer.

According to MEDDEV 2.4/1 rev.9 relating to rule 8, fi rst hyphen of Annex IX to directive 93/42/EEC, examples of medical devices to be placed in the teeth such as bridges and crowns, dental fi lling materials and pins and dental alloys ceramics and polymers are to be classifi ed as Class IIa medical devices.

According to the same directive and rule 8 of Annex IX to directive 93/43/EEC, since they are placed directly in the gum, dental abutments should be considered as implantable devices as well as dental implants meaning they are classifi ed as Class IIb medical devices.

The medical device directive state that review and QMS implementation will be verifi ed along with the technical fi le and clinical investigation documents. Conformity assessment by a Notifi ed Body is required before affi xing a CE mark. This means among others that an audit of the full quality assurance system according to ISO 13485:2012 must be carried out. Dental labs and or dentists that make individual abutments that fi t the implants for their patients are thus seen as Class IIb medical device manufacturers.

2017/745: However, there is still ambiguity surrounding the classifi cation of dental abutments as class IIa or IIb. The speaker announced that he was sure that many dental labs and (restorative) dentists are not aware of this hurdle and the impact this can have on everyday dental implant practice.

The evidence used by the speaker throughout his presentation is summarised in Figure 7.

References

Bower JL, Christensen CM. Disruptive Technologies: Catching the Wave. Harvard Business Review 73, no. 1 (January–February 1995): 43–53.

Huang SH, Liu P, Mokasdar A. et al. Int J Adv Manuf Technol 2013; 67:1191. https://doi.org/10.1007/s00170-012-4558-5. �



Figure 6

Figure 5

Anssari Moin D, Hassan B, Parsa A, Mercelis P, Wismeijer D. Accuracy of preemptively constructed, Cone Beam CT-, and CAD/CAM technology-based, individual Root Analogue Implant technique: An in vitro pilot investigation. Clin Oral Implants Res. 2014 May 25 (5) 598-602.


Figure 7


3D printing in dentistry TYPE II / III Prospective studies Clinical experience

Customized dental implants TYPE III Clinical experience

Legislation Law


The following report summarises the chairperson’s introduction to the Diagnosis and treatment planning in implant dentistry in light of the prevalence of peri-implant diseases session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Diagnosis and treatment planning in implant dentistry in light of the prevalence of peri-implant diseasesNikolaos DonosEAO Congress Scientific Report; (3), 92–93, 2018.

A non-negligible problemIt has been shown that peri-implantitis affects as many as 10% of implants and 20% of patients after 5–10 years of follow-up (Mombelli et al. 2012). Due to the variability of these figures, this data should be taken with caution and is not suitable for meta-analysis. In spite of this, there is no doubt that we are dealing with a problem that cannot be ignored.

In a recent systematic review comparing treatment outcomes in healthy and periodontitis patients, survival rates clearly were significantly lower in the latter. It can be concluded (Sousa et al. 2016) that:

� implants in patients treated for periodontal disease are associated with a higher incidence of biological complications, and lower success and survival rates

� severe forms of periodontal disease are associated with higher rates of implant loss

In a cohort study on patients receiving supportive periodontal therapy, the prevalence of patients with mucositis was 24.7%, and peri-implantitis was 15.1% (Aguirre-Zorzano et al. 2015). Analysis of this data allows us to identify a predictive profile with patient-based risk assessments for the occurrence of plaque-induced and prosthetically and surgically triggered peri-implantitis (Canullo et al. 2016).

Early detection

The early detection and treatment of mucositis and peri-implantitis has recently become a part of the current implant treatment protocol, and is now considered a normal requirement. It is becoming increasingly important to recognise risk factors in order to prevent complications. Several risk factors were identified long ago: poor oral hygiene; history of periodontitis; presence of pockets and bleeding on probing; smoking; and diabetes. There is less evidence to support alcohol consumption, specific genetic traits and implant surface type as risk factors (Heitz-Mayfield. 2008).

Early interventionThe treatment of peri-implantitis requires earlier surgical interventions than that of periodontitis. Additionally, early explantation can often be associated with an adverse condition which is difficult to treat. The primary method for preventing peri-implantitis is the management of peri-implant mucositis through proper plaque control, professional intervention and adjunctive measures. Of course, from the beginning of treatment, emphasis should be placed on the proper 3D position of the implant and a prosthesis design which enables good oral hygiene (Jepsen et al. 2014).

Patient expectations

In addition, many patients may have unrealistic expectations about implant therapy (Abrahamsson et al. 2017). We need to inform them that there is no guarantee of a complication-free treatment and that implants, like teeth, need continuous care.

Current challenges

As a direct consequence, there are four challenges which must be addressed:

� control risk factors to prevent disease � personalise therapy � manage unrealistically high patient expectations � identify the best surgical techniques for

reconstructing the defects

References

Abrahamsson KH, Wennström JL, Berglundh T, Abrahamsson I. Altered expectations on dental implant therapy; views of patients referred for treatment of peri-implantitis. Clin Oral Implants Res. 2017 Apr;28(4):437–442. doi: 10.1111/clr.12817. Epub 2016 Feb 25.

Aguirre-Zorzano LA, Estefanía-Fresco R, Telletxea O, Bravo M. Prevalence of peri-implant inflammatory disease in patients with a history of periodontal disease who receive supportive periodontal therapy. Clin Oral Implants Res. 2015 Nov;26(11):1338–44. doi: 10.1111/clr.12462. Epub 2014 Aug 12.


Canullo L, Tallarico M, Radovanovic S, Delibasic B, Covani U, Rakic M. Distinguishing predictive profiles for patient-based risk assessment and diagnostics of plaque induced, surgically and prosthetically triggered peri-implantitis. Clin Oral Implants Res. 2016 Oct;27(10):1243–1250. doi: 10.1111/clr.12738. Epub 2015 Nov 20.

Heitz-Mayfield LJ. Peri-implant diseases: diagnosis and risk indicators. J Clin Periodontol. 2008 Sep;35(8 Suppl):292–304. doi: 10.1111/j.1600-051X.2008.01275.x.

Jepsen S, Berglundh T, Genco R, Aass AM, Demirel K, Derks J, Figuero E, Giovannoli JL, Goldstein M, Lambert F, Ortiz-Vigon A, Polyzois I, Salvi GE, Schwarz F, Serino G, Tomasi C, Zitzmann NU. Primary prevention of peri-implantitis: managing peri-implant mucositis. J Clin Periodontol. 2015 Apr;42 Suppl 16:S152–7. doi: 10.1111/jcpe.12369.

Sousa V, Mardas N, Farias B, Petrie A, Needleman I, Spratt D, Donos N. A systematic review of implant outcomes in treated periodontitis patients. Clin Oral Implants Res. 2016 Jul;27(7):787–844. doi: 10.1111/clr.12684. Epub 2015 Sep 18. �




The following report summarises the fi rst paper presented during the Diagnosis and treatment planning in implant dentistry in light of the prevalence of peri-implant diseases session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

Infection control and early detection of peri-implantitisLisa Heitz-Mayfi eldEAO Congress Scientifi c Report; (3), 94–96, 2018.

Infection controlOne of the main methods for preventing peri-implantitis in periodontitis patients is to place implants only when infection control has been fully achieved. Periodontal therapy should be completed prior to placement of dental implants. After the prosthesis has been placed, a supportive periodontal treatment (SPT) protocol should be implemented and tailored to each patient’s individual risk profi le (Figure 1).

The incidence of peri-implantitis in periodontitis patients has been shown to correlate with maintenance care, plaque score during SPT treatment, and the cleansability of the prostheses (Roccuzzo et al. 2011; Aguirre-Zorzano et al. 2015; Serino & Ström 2009). In cases where SPT was not given, the odds ratio for the occurrence of peri-implantitis rose to 5.9 (Costa et al. 2012). Marginal bone loss at implants has also been shown to be associated with patients who have deep periodontal pockets at teeth (Cho-Yan Lee et al. 2012). It is therefore necessary for deep periodontal pockets to be eliminated.

Regular monitoring

The body of evidence underscores the need for early detection of complications through regular monitoring (Figures 2–3). Measurements should be compared to the baseline data, and should take into account the particular dimensions of each implant system (Heitz-Mayfi eld. 2013 and 2014; Lang & Berglundh. 2011) (Figure 4). Early identifi cation of complications allows them to be managed early before they can progress and cause further damage (Figures 5–6). Various tests on infl ammatory mediators are being developed to assist with early diagnosis of biological peri-implant complications (Dursun & Tozum 2016; Rathnayake et al. 2017).

The early diagnosis of prosthetic complications is also important, for instance: misfi tting, loose or fractured components; inadequate access for hygiene; presence of foreign bodies such as luting cement (de Araujo Nobre & Malo. 2014). Finally, in a ten-year clinical study, lack of keratinised peri-implant mucosa may be associated with increased plaque accumulation, mucosal recession and higher number of diseased implants (Roccuzzo et al. 2016).

Once diagnosed, peri-implant mucositis must be treated by peri-implant debridement and removal of biofi lm. This is a pre-requisite for primary

Figure 1

Comprehensive Examination Initial cause related therapyExtraction hopeless teeth

Additional Periodontal Therapy

Periodontal Reevaluation

Diagnostic Phase Tissue response to therapyPlaque controlPatient complianceTooth prognosis

Supportive Periodontal Therapy

Regenerative

Resective

Access ßap

Non-surgical therapy

Periodontal surgery

Achieve infection control prior to implant placement

Figure 2

Baseline measures Record baseline peri-implant probing measurements

• use light probing force 0.25N • metal or plastic probe • record probing depth, soft tissue level • record bleeding • record 4 sites per implant • prosthesis contours may limit access

Prevention and management of biologic and technical implant complications Heitz-Mayfield et al. 2014. IJOMI2

7th European Workshop on Periodontology 2011 Lang & Berglundh 2011 J Clin Perio

Figure 3

Baseline measures Take a radiograph to establish radiographic crestal bone levels

• correct alignment of sensor and tube • use paralleling device • assess peri-implant bone levels • verify seating of prosthesis • identify excess cement

3Prevention and management of biologic and technical implant complications Heitz-Mayfield et al. 2014. IJOMI7th European Workshop on Periodontology 2011 Lang & Berglundh 2011 J Clin Perio

Figure 4

SBLINBTIAOI

Be aware of expected bone levels according to implant system

• Implant design influences crestal bone modeling

• No sig difference in bone levels between AOI and SBLI

• AOI and SBLI preserved sig more crestal bone than NBTI

Preservation of crestal bone by implant design. A comparative study in minipigs Heitz-Mayfield et al. 2013 COIR


prevention of peri-implantitis (Salvi & Zitzmann. 2014; Jepsen et al. 2015).

Conclusion

The importance of a regular maintenance programme is crucial. This is shown by a study which reported that one out of fi ve patients would experience peri-implantitis, if they went for a fi ve-year period without receiving SPT (Rokn et al. 2017). A recall interval of a minimum of six months is the standard recommendation, since implants may require more frequent maintenance than teeth (Monje et al. 2016). However, it is highly advisable to optimise the maintenance programme for each patient’s needs (Figure 7).

In conclusion, while infection control reduces the risk of peri-implantitis, early detection can reduce the damage done by the disease (Figure 8).

References

Aguirre-Zorzano LA, Estefanía-Fresco R, Telletxea O, Bravo M. Prevalence of peri-implant infl ammatory disease in patients with a history of periodontal disease who receive supportive periodontal therapy. Clin Oral Implants Res. 2015 Nov;26(11):1338–44. doi: 10.1111/clr.12462. Epub 2014 Aug 12.

Cho-Yan Lee J, Mattheos N, Nixon KC, Ivanovski S. Residual periodontal pockets are a risk indicator for peri-implantitis in patients treated for periodontitis. Clin Oral Implants Res. 2012 Mar;23(3):325–33. doi: 10.1111/j.1600-0501.2011.02264.x. Epub 2011 Aug 5.

Costa FO, Takenaka-Martinez S, Cota LO, Ferreira SD, Silva GL, Costa JE. Peri-implant disease in subjects with and without preventive maintenance: a 5-year follow-up. J Clin Periodontol. 2012 Feb;39(2):173–81. doi: 10.1111/j.1600-051X.2011.01819.x. Epub 2011 Nov 23.

de Araújo Nobre MA, Maló P. The infl uence of rehabilitation characteristics in the incidence of peri-implant pathology: a case-control study. J Prosthodont. 2014 Jan;23(1):21–30. doi: 10.1111/jopr.12114. Epub 2014 Jan 2.

Dursun E, Tözüm TF. Peri-Implant Crevicular Fluid Analysis, Enzymes and Biomarkers: a Systemetic Review. J Oral Maxillofac Res. 2016 Sep 9;7(3):e9.

Jepsen S, Stadlinger B, Terheyden H, Sanz M. Science transfer: oral health and general health – the links between periodontitis, atherosclerosis and diabetes. J Clin Periodontol. 2015 Dec;42(12):1071-3. doi: 10.1111/jcpe.12484. Epub 2016 Jan 5.

Heitz-Mayfi eld LJ, Darby I, Heitz F, Chen S. Preservation of crestal bone by implant design. A comparative study in minipigs. Clin Oral Implants Res. 2013 Mar;24(3):243–9. doi: 10.1111/j.1600-0501.2012.02513.x. Epub 2012 Jun 19.

Heitz-Mayfi eld LJ, Mombelli A. The therapy of peri-implantitis: a systematic review. Int J Oral Maxillofac Implants. 2014;29 Suppl:325–45. doi: 10.11607/jomi.2014suppl.g5.3.

Lang NP, Berglundh T; Working Group 4 of Seventh European Workshop on Periodontology. Periimplant diseases: where are we now?--Consensus of the Seventh European Workshop on Periodontology. J Clin Periodontol. 2011 Mar;38 Suppl 11:178–81. doi: 10.1111/j.1600-051X.2010.01674.x.

Monje A, Aranda L, Diaz KT, Alarcón MA, Bagramian RA, Wang HL, Catena A. Impact of Maintenance Therapy for the Prevention of Peri-implant Diseases: A Systematic Review and Meta-analysis. J Dent Res. 2016 Apr;95(4):372–9. doi: 10.1177/0022034515622432. Epub 2015 Dec 23.

Rathnayake N, Gieselmann DR, Heikkinen AM, Tervahartiala T, Sorsa T. Salivary Diagnostics-Point-of-Care diagnostics of MMP-8 in dentistry and medicine. Diagnostics (Basel). 2017 Jan 20;7(1). pii: E7. doi: 10.3390/diagnostics7010007.

Figure 5

Regular monitoring for early detection of inflammation

• identify calculus, plaque, • oedema, erythema • BoP, suppuration • draining sinus • peri-implant probing • remove prosthesis if required

take a radiograph if clinical signs of inflammation are present to confirm diagnosis

5Prevention and management of biologic and technical implant complications Heitz-Mayfield et al. 2014. IJOMI

Figure 6

•assess contours for cleansability •interproximal contact areas •prosthetic components •screw access restoration •chipping, signs of wear •assess occlusion

Prevention and management of biologic and technical implant complications Heitz-Mayfield et al. 2014 IJOMI

Examine implant-supported prosthesis

Prevalence of interproximal open contacts between single-implant restorations and adjacent teeth Varthis et al. 2016 IJOMI

A 5 year retrospective assay of implant treatments and complications in private practice Wang et al. 2016 Int J Prosthodont

Regular monitoring for early detection of complications

Figure 7

27 yr old female non-periodontal patient tooth loss due to trauma

Optimise maintenance to patients needs

78 yr old male periodontally healthy poor dexterity tooth loss due to root resorption

52 yr old male heavy bruxer diabetes mellitus treated for peri-implantitis

28 yr old male history aggressive periodontitis heavy smoker

Individual Risk Profile6 monthly 3 monthly

Figure 8

Infection Control Reduce Risk

Early Detection Reduce Damage


Roccuzzo M, Bonino F, Bonino L, Dalmasso P. Surgical therapy of peri-implantitis lesions by means of a bovine-derived xenograft: comparative results of a prospective study on two different implant surfaces. J Clin Periodontol. 2011 Aug;38(8):738–45. doi: 10.1111/j.1600-051X.2011.01742.x. Epub 2011 Jun 2.

Roccuzzo M, Grasso G, Dalmasso P. Keratinized mucosa around implants in partially edentulous posterior mandible: 10-year results of a prospective comparative study. Clin Oral Implants Res. 2016 Apr;27(4):491–6. doi: 10.1111/clr.12563. Epub 2015 Feb 23.

Rokn A, Aslroosta H, Akbari S, Najafi H, Zayeri F, Hashemi K. Prevalence of peri-implantitis in patients not participating in well-designed supportive periodontal treatments: a cross-sectional study. Clin Oral Implants Res. 2017 Mar;28(3):314–319. doi: 10.1111/clr.12800. Epub 2016 Feb 26.

Salvi GE, Zitzmann NU. The effects of anti-infective preventive measures on the occurrence of biologic implant complications and implant loss: a systematic review. Int J Oral Maxillofac Implants. 2014;29 Suppl:292–307. doi: 10.11607/jomi.2014suppl.g5.1.

Serino G, Ström C. Peri-implantitis in partially edentulous patients: association with inadequate plaque control. Clin Oral Implants Res. 2009 Feb;20(2):169–74. doi: 10.1111/j.1600-0501.2008.01627.x. Epub 2008 Dec 1. �




The following report summarises the second paper presented during the Diagnosis and treatment planning in implant dentistry in light of the prevalence of peri-implant diseases session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

Focus on implant selection, surgical placement and restorative designMauro MerliEAO Congress Scientifi c Report; (3), 97–99, 2018.

Peri-implantitis may be caused and/or exacerbated by a number of iatrogenic factors: residual cement; inadequate seating of the abutment on the implant; implant malposition; a poorly fi tting framework; over-contouring of restorations; and technical complications (Lang et al. 2011).

This presentation explored the best techniques for addressing peri-implantitis from the very beginning. The speaker argued that the true prevention of peri-implantitis lies in diagnosis and planning, and continues with correct surgically and prosthetically driven treatments, and ends with good long-term supportive care.

Implant selection

The use of narrow diameter implants is documented in all regions but only with short-term results (Klein et al. 2014; Ioannidis et al. 2015). In some cases, narrow implants may provide a simple solution (for example, in a thin anterior mandible), provided that the possible mechanical complications are considered.

Short implants are supported by clinical evidence (even in the long-term), especially in the posterior mandible (Esposito et al. 2014; Lee et al. 2014; Camps-Font et al. 2016; Tong et al. 2017; Fan et al. 2017; Toti et al. 2017). They can often provide a minimally invasive solution in cases which are less demanding in relation to prosthetics.

Surgical placement

Suboptimal treatments may lead ultimately to peri-implantitis, but this can be avoided if the correct treatment steps are followed. This is especially the case with GBR, a predictable technique which allows implant placement in both horizontally and vertically atrophic areas.

The long-term stability of augmented bone has been widely proven, and so it should not be assumed that GBR paves the way for further onset of peri-implantitis. On the contrary: if implants are placed without adequate bone volume, peri-implantitis is more likely to occur.

Interestingly, in two recent systematic reviews, no differences were observed comparing non-resorbable ePTFE membranes and resorbable collagen membranes (Sanz-Sánchez et al. 2015; Merli et al. 2016). According to the speaker, during the fi rst four-week period three out of four phases of the wound healing process had already occurred. When the collagen membrane was about to disappear, cells were oriented towards bone tissue. Thus, by that point the barrier was no longer necessary.

In vertical augmentation, a recent meta-analysis found lower levels of resorption and complications following GBR compared to distraction osteogenesis and block grafting (Clementini et al. 2012; Elnayef et al. 2017).

The speaker then described the so-called ‘fence technique’. Space is maintained by a micro-plate (previously prepared in the stereolithographic model) screwed in the mouth and covered by a resorbable collagen membrane. This represents a more conservative approach, since results can be achieved with fewer complications than when a non-resorbable membrane is used (Clementini et al. 2012; Elnayef et al. 2017) (Figure 1).

The ‘wafer technique’ (Merli et al. 2017) was also described. This technique involves using a thin

Figure 1

Clinical case

Figure 2

Wafer Technique

9 m

m in

hei

ght

6 mm in width


cortical wall as a boundary, and housing a mixture of particulated autograft and xenograft materials which is then covered by a collagen membrane. This allows us to convert a vertical defect into a (more predictable) horizontal defect. It could be a method for restoring bone defects caused by peri-implantitis (Figures 2–3).

Restorative design

The prosthesis is the part of the implant where supracrestal tissues are sealed. Over-contouring of the prosthesis (usually caused by implant malposition) disturbs this seal and is an iatrogenic factor leading to mucositis. Often, augmentation procedures are the only way to avoid this.

Decision-tree

Finally, the speaker shared an umbrella review which is still in preparation. It is a review of systematic reviews (of RCTs), with the aim of providing guidelines for treating partially edentulous cases with bone defects. The speaker’s proposed decision-tree is outlined in Figure 4.

References

Camps-Font O, Burgueño-Barris G, Figueiredo R, Jung RE, Gay-Escoda, Valmaseda-Castellón E. Interventions for Dental Implant Placement in Atrophic Edentulous Mandibles: Vertical Bone Augmentation and Alternative Treatments. A Meta-Analysis of Randomized Clinical Trials. J Periodontol. 2016 Dec;87(12):1444–1457. Epub 2016 Jul 29.

Clementini M, Morlupi A, Canullo L, Agrestini C, Barlattani A. Success rate of dental implants inserted in horizontal and vertical guided bone regenerated areas: a systematic review. Int J Oral Maxillofac Surg. 2012 Jul;41(7):847–52. doi: 10.1016/j.ijom.2012.03.016. Epub 2012 Apr 26.

Elnayef B, Monje A, Gargallo-Albiol J, Galindo-Moreno P, Wang HL, Hernández-Alfaro F. Vertical Ridge Augmentation in the Atrophic Mandible: A Systematic Review and Meta-Analysis. Int J Oral Maxillofac Implants. 2017 Mar/Apr;32(2):291–312. doi: 10.11607/jomi.4861.

Esposito M, Ardebili Y, Worthington HV. Interventions for replacing missing teeth: different types of dental implants. Cochrane Database of Systematic Reviews 2014, Issue 7. Art. No.: CD003815. DOI: 10.1002/14651858.CD003815.pub4

Fan T, Li Y, Deng WW, Wu T, Zhang W. Short Implants (5 to 8 mm) Versus Longer Implants (>8 mm) with Sinus Lifting in Atrophic Posterior Maxilla: A Meta-Analysis of RCTs. Clin Implant Dent Relat Res. 2017 Feb;19(1):207–215. doi: 10.1111/cid.12432. Epub 2016 Jun 13.

Ioannidis A, Gallucci GO, Jung RE, Borzangy S, Hämmerle CH, Benic GI. Titanium-zirconium narrow-diameter versus titanium regular-diameter implants for anterior and premolar single crowns: 3-year results of a randomized controlled clinical study. J Clin Periodontol. 2015 Nov;42(11):1060–70.

Klein MO, Schiegnitz E, Al-Nawas B. Systematic review on success of narrow-diameter dental implants. Int J Oral Maxillofac Implants. 2014;29 Suppl:43–54. doi: 10.11607/jomi.2014suppl.g1.3.

Lang NP, Berglundh T; Working Group 4 of Seventh European Workshop on Periodontology. Periimplant diseases: where are we now?--Consensus of the Seventh European Workshop on Periodontology. J Clin Periodontol. 2011 Mar;38 Suppl 11:178–81. doi: 10.1111/j.1600-051X.2010.01674.x.

Lee SA, Lee CT, Fu MM, Elmisalati W, Chuang SK. Systematic review and meta-analysis of randomized controlled trials for the management of limited vertical height in the posterior region: short implants (5 to 8 mm) vs longer implants (> 8 mm) in vertically augmented sites. Int J Oral Maxillofac Implants. 2014 Sep–Oct;29(5):1085–97. doi: 10.11607/jomi.3504.

Merli M, Merli I, Raffaelli E, Pagliaro U, Nastri L, Nieri M. Bone augmentation at implant dehiscences and fenestrations. A systematic review of randomised controlled trials. Eur J Oral Implantol. 2016 Spring;9(1):11–32.

Merli M, Moscatelli M, Mariotti G, Motroni A, Mazzoni A, Mazzoni S, Breschi L, Nieri M. A Novel Approach to Bone Reconstruction: The Wafer Technique. Int J Periodontics Restorative Dent. 2017 May/Jun;37(3):317–325. doi: 10.11607/prd.3055.

Sanz-Sánchez I, Ortiz-Vigón A, Sanz-Martín I, Figuero E, Sanz M. Effectiveness of Lateral Bone Augmentation on the Alveolar Crest Dimension: A Systematic Review and Meta-analysis. J Dent Res. 2015 Sep;94(9 Suppl):128S–42S. doi: 10.1177/0022034515594780. Epub 2015 Jul 27.

Figure 3

Figure 4

From the Umbrella review to the clinical practice: a decisional tree

Bone defects? Traditional implant treatment without augmentation

NO

YES

Type of defect VERTICAL defect

Can short implants be used? Can they lead to a favorable prosthetic design?

YES

SHORT Implants

NO

Bone Augmentation

HORIZONTAL defect

Prosthetic Virtual Planning

Has the bone defect 2 or more walls?

YES

One-Stage GBR

NO

Two-Stage Bone Augmentation

NARROW implants: a smart solution not yet enough

documented in literature compared with standard implants + bone augmentation


Tong Q, Zhang X, Yu L. Meta-analysis of Randomized Controlled Trials Comparing Clinical Outcomes Between Short Implants and Long Implants with Bone Augmentation Procedure. Int J Oral Maxillofac Implants. 2017 Jan/Feb;32(1):e25–e34. doi: 10.11607/jomi.4793. Epub 2016 Nov 11.

Toti P, Marchionni S, Menchini-Fabris GB, Marconcini S, Covani U, Barone A. Surgical techniques used in the rehabilitation of partially edentulous patients with atrophic posterior mandibles: A systematic review and meta-analysis of randomized controlled clinical trials. J Craniomaxillofac Surg. 2017 Aug;45(8):1236–1245. doi: 10.1016/j.jcms.2017.04.011. Epub 2017 Apr 27. �




The following report summarises the chairperson’s introduction to the How to approach the treatment of the patient with hopeless implants session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

How to approach the treatment of the patient with hopeless implantsLuca CordaroEAO Congress Scientific Report; (3), 100, 2018.

High survival and success rates have been documented in the long-term for implant treatments and implant-supported restorations. It is also well known that we can achieve good clinical outcomes with reduced treatment-time protocols and with bone and soft tissue augmentation. However, failures can still occur. This session addressed the following questions:

� why and when should we remove an implant? � how can we restore patients after implant

removal?

The first reason for implant removal is peri-implantitis. A precise definition of this disease and its diagnostic parameters is still lacking.

Consequently, the reported prevalence of the condition varies between studies. Despite the various treatment approaches applied, some implants do not show clinical resolutions. Instead, they progress and the disease recurs, and the implant must ultimately be removed. The second reason is malpositioned implants.

When implants need to be removed we can sometimes keep the hopeless implants for a transitional phase to allow the patient to keep a fixed provisional restoration while augmentation and/or placement of new implants is performed. Timing of implant removal should be carefully considered in these complex treatment plans. �




The following report summarises the first paper presented during the How to approach the treatment of the patient with hopeless implants session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Management of hopeless implants in partially edentulous patients in aesthetic areasMassimo SimionEAO Congress Scientific Report; (3), 101, 2018.

For implants outside of the bony envelope and with the wrong angulation, the only available option is removal.

Other situations involve infected implants, caused by infection in an adjacent tooth, root remnants or inflammation caused by cement or biomaterials. The biggest issue in these cases is not to remove the infected implant but to reconstruct the residual bony defects left by the infection.

To rebuild bone in these residual defects, the speaker recommended using staged guided bone regeneration (GBR) with non-resorbable membranes in the conventional method. During re-entry to place the new implant, the speaker uses a hybrid implant surface: rough in the apical portion and machined in the most coronal portion. The speaker also performs simultaneous soft tissue augmentation (either an autogenous connective graft or a dermis matrix xenograft). �




The following report summarises the second paper presented during the How to approach the treatment of the patient with hopeless implants session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

How to approach the treatment of the patient with hopeless implantsKarl-Ludwig AckermannEAO Congress Scientific Report; (3), 102, 2018.

Critical casesComplex cases which involve numerous deviations from the norm require a multi-staged treatment approach. It is also important that the patient understands that a restitutio ad integrum cannot be always assured.

The speaker presented his first clinical case to illustrate the available treatment options. This case involved a high smile line and a large bony defect affecting three missing incisors; all parameters deviated from the norm. The speaker stressed how important it was that the patient be made aware of the complexity of the case and that their situation, involving a limited bone reconstruction, soft tissue deficiencies, unequal gingival contours and missing papillae, meant that the final aesthetic outcome may be compromised. These types of cases may benefit from the use of pink porcelain.

The speaker’s protocol started with the removal of the hopeless implant, GBR to preserve as much as tissue possible, and a transitional restoration. The second step involved augmentation using bone-blocks. After four months, a new implant was placed; four months later, the implant was uncovered along with simultaneous muco-gingival surgery. The second provisional and the final prosthesis were finished with pink material to mask the insufficient levels of bone augmentation which had been achieved. Insufficient bone levels were caused by:

� lower levels of bone build-up (which were predetermined by the defect size, geometry, and levels of adjacent dental bone)

� compromised papillae formation (this is often the case when multiple teeth are missing)

� malpositioned implants, which have poor potential for reconstructive outcomes

The speaker’s second case presented severe vertical and horizontal hard and soft tissue defects, and consequently showed inadequate crown length. As in the preceding case, the patient was first informed of the difficulties of the treatment and the possible outcomes to be expected.

The protocol involved a similar approach. After the malpositioned implants were removed, augmentation using iliac bone-blocks was performed. Four months later, four implants were placed using a surgical guide and a transitional prosthesis was placed. Three and a half years later, an implant impression was taken and a definitive prosthesis was manufactured using pink porcelain to help mimic the lost papillae.

This case illustrated that bone augmentation should only be performed in patients over the age of 20 and that when limited soft tissue volumes are available, the aesthetic outcome can be compromised. Multi-staged treatment plans are required, and it is important that no time pressure is present. �




The following report summarises the third paper presented during the How to approach the treatment of the patient with hopeless implants session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

How to approach the treatment of the patient with hopeless implants in the totally edentulous maxillaJoan Pi UrgellEAO Congress Scientifi c Report; (3), 103, 2018.

Implants may be rendered hopeless by malposition or biological complications. Sometimes, a combination of the two can occur, as the former may lead to the latter.

After removing the malpositioned implants, a large bone reconstruction should be performed to achieve the correct gingival and aesthetic architecture. Guided surgery is the ideal tool for preventing this problem and for facilitating placement in the appropriate position according to the planned prosthesis and the patient’s biology.

The second cause of hopeless implants is peri-implantitis. There is still no consensus about the defi nition of this disease (Tallarico et al. 2016), and it is currently debated whether statistically we have experienced a ‘tsunami’ or a marginal problem.

The bony defects left by explantation in the edentulous maxilla can be approached in different ways:

� autologous bone grafts � zygomatic implants � GBR with non-resorbable titanium reinforced

e-PTFE membranes (Simion et al. 1994)

Autogenous bone grafts were traditionally harvested from the iliac crest. Now, however, this practice is becoming less common due to the morbidity of the procedure, especially in the hip.

On the other hand, the use of zygomatic implants is increasing. This is perhaps because it has lower associated morbidity. It is a rapid procedure, especially in cases involving immediate function protocols. However, with graftless solutions, the results obtained are not the same as with 3D augmentation. Reconstructions using bone grafts can sometimes lead to type 1 prostheses without pink aesthetic material (Brånemark, Grondahl & Worthington. 2001).

In the maxilla, GBR was frequently performed simultaneously with bilateral sinus grafting.

The speaker proposed a classic GBR protocol with non-resorbable titanium reinforced e-PTFE

membranes and fi xed by thumb-tacks. To promote vascularisation, the bony bed can be drilled and a mixed graft of autogenous bone and xenografts can be used to improve osseoconduction.

The speaker stated that after 25 years, an increase in peri-implantitis has coincided with the generalised use of rough surfaces. Therefore, the speaker uses hybrid implants with 75% of the surface (apical) treated and 25% (coronal) machined. This is because when a rough surface is exposed, is more susceptible to biofi lm accumulation than machined surfaces.

Conclusions

The main concepts presented by the speaker are summarised in Figure 1.

References

Bränemark PI, Grondahl K, Worthington P. Osseointegration and autogenous onlay bone grafts: reconstruction of the edentulous atrophic maxilla. Chicago, IL: Quintessence Publishing, 2001:112–34

Simion M, Trisi P, Piattelli A. Vertical ridge augmentation using a membrane technique associated with osseointegrated implants. Int J Periodontics Restorative Dent. 1994 Dec;14(6):496–511.

Tallarico M, Monje A, Wang HL, Galindo Moreno P, Xhanari E, Canullo L. A systematic review on the definition of periimplantitis: limits related to the various diagnoses proposed. J Oral Science Rehabilitation. 2016 Dec;2(4):42–53. �



Figure 1


The following report summarises the debate which took place during the How to approach the treatment of the patient with hopeless implants session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

DebateMassimo Simion, Karl-Ludwig Ackermann and Joan Pi UrgellEAO Congress Scientific Report; (3), 104, 2018.

How can we define a hopeless implant?

When does a failing implant become a hopeless implant? When it is not possible to be kept in the mouth, or when the best treatment decision is to remove it (because it cannot achieve health, function and aesthetics).

Late biological failure is a multifactorial process, and even two implants which look similar may have different responses in different patients. Maybe

‘hopeless’ is a misleading term, and we should rather view success as the absence of complications.

Patient satisfaction is also an issue, as there can be wide variations in patient acceptance rates. Having said that, this session focused on extreme cases where implants were undoubtedly hopeless and nothing could be done to maintain them; and on the subsequent problems which had been caused by a hopeless implant.

How frequently do these problems appear?About a third of implants may encounter complications over a five-year period, so failures are rather common. It is important that we describe

complications as a part of the treatment. A history of periodontitis is a major risk indicator. Although still considered a risk factor, smoking currently appears to be less relevant than periodontitis.

What should we do?

Complication prevention begins with a proper diagnosis, treatment planning and risk evaluation; it continues with well executed surgical and prosthodontic procedures; and ends with a proper maintenance protocol.

A therapeutic dilemma?

Patient acceptance for implant removal is low. Patients tend to assume that implant failures are a result of treatment or operator error; they do not usually consider themselves or their circumstances as the cause of the failure. Therefore, we may be put under pressure to keep a hopeless implant to satisfy the patient. On the other hand, however, when dealing with peri-implantitis we still do not have an effective treatment which offers predictable outcomes. But we can now say that peri-implantitis is treatable and that good long-term stability can be achieved in some clinical situations. �




The following report summarises the first paper presented during the Liaison for the best patient service. Analogue versus digital session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

Over the last twenty years, dentistry has evolved from analogue to digital in clinical and technical settings. Even when using analogue surgical templates – or when performing traditional prosthodontic treatments – the procedures involved are made up of a number of digital steps.

The same shift has occurred in laboratories, where work is carried out using CAD/CAM techniques, and the technician’s task is to give the ‘final touches’ to the prostheses. With the introduction of so many digital techniques, the choice between analogue and digital is becoming less of a choice and more of an inevitability.

The analogue clinician with a combined digital-analogue technicianOriol Llena and August BrugueraEAO Congress Scientific Report; (3), 105–107, 2018.

The result is the sameTechnicians have little to no contact with patients. Communication between clinicians and technicians is therefore vital for achieving clinical success and meeting patients’ requests. The main restorative parameters of shape and position (such as: size of central incisors, medium line, tissue volume, position of incisal edge) can be found in the wax-up. The only feature which is lacking from this is colour. The restorative parameters may be sent to the laboratory by analogue or digital means. It is possible for either approach to get the same results.

Two major advances in the field of dentistry have been the use of adhesion and implants to restore or replace teeth. Both techniques have the highest patient’s demand in common: aesthetics. Technically, the best way to get a satisfactory result in highly demanding aesthetic cases (like reproducing a single central) is by stratification or build-up techniques, that is by direct composites in the clinic or porcelain in the laboratory. A digital approach can simplify procedures and bring clear advantages, especially in the laboratory; it should be noted, however, that these advantages are not so apparent chair-side. As the digital workflow improves it will replace the analogue flow which, in many cases, is well established.

The most important step: wax-up

A wax-up (analogue or digital) aims to obtain a functional and aesthetic mock-up. Digital wax-ups can provide valuable information for the technician to create the analogue wax-up. The complete digital workflow (diagnostic, digital wax-up and digitally printed mock-up) has some limitations. Once the wax-up is finished, it is easy to create a transparent silicone guide to make the mock-up directly in the mouth with light-cured composite flow, creating a real analogue mock-up of vital importance.

Different sectors, different materialsIn the posterior area, the use of more resistant monolithic materials is advantageous; but in the aesthetic zone, the speakers remarked that they obtain better aesthetic results with analogue stratification than with staining (Figures 1–2).

When using lithium disilicate, adjustments should be made before crown crystallisation in order to avoid cracks. The speakers described a comparison between the details of occlusal morphology obtained using three different machines; significant differences in precision were found which could be important in the aesthetic zone. However, the design of the crown

– along with technician experience – is the most relevant factor, as in analogue workflows (Figure 3).

When analysing the marginal fit, the speakers stated that they often find over-contoured margins. This may be due to the method used by milling machines

Figure 1

Figure 2


to prevent fractures during fabrication (Figure 4). Regardless, it is the technician’s responsibility to eliminate over-contouring if it occurs.

For stratification or build-up, the speakers described three materials which are available. These materials have similar advantages and limitations as previously outlined (Figure 5).

Time and cost

The speakers described another study which involved a case resolved in three different ways: stratification of feldspathic porcelain, CAD/CAM, and injected ceramic (Press Ceram). For the last two procedures, which were both digital, precision levels seemed to be lower than those achieved using the analogue method, especially on the crown contours. This suggests that morphological details can only be achieved by manual manufacturing.

Although satisfactory results can be obtained using each of the three methods, differences in time and cost were evident. The cost of learning, purchasing machine components and materials, as well as the overall time investment were higher in the digital approach (Figure 6).

Colour

Because of patients’ aesthetic requirements, colour is often the most important and visible parameter for measuring success. Replacing a single incisor can be more demanding than a six-tooth restoration in the anterior region. The colour of the cement to be used needs to be carefully selected, as does the colour of the prepared tooth.

To effectively communicate colour values to the lab, white-balanced polarised light pictures are recommended. In this way, the shape and colour of the dentin can be extrapolated. It is not difficult to do this using modern digital cameras. Polarised pictures can be analysed in photography using a number of editing applications, like Photoshop, with high levels of precision and without the usual colour guides. The colour of ceramics should be digitalised and then compared with the picture of the tooth, after being balanced using a grey card (Figure 7).

Just knowing the digital parameters of colour alone, we cannot predict if a case should be treated using laminates or crowns, how much width is required, and which material should be used to match the colour of the adjacent tooth, but it can help us. In the end, only experience will lead us to the right choice.

Recommendations

To restore a single implant in the anterior teeth, the speakers proposed cementing a coping of zirconia to the metallic abutment in the lab and a lithium disilicate perforated crown personalised if possible with the patient in the laboratory on the zirconia coping outside of the patient’s mouth, then screwing the customised screw-retained prosthesis into the implant.

Figure 3

Figure 4

Figure 6

Figure 5

Figure 7


Figure 8

The speakers stated that the most important decision to be made during treatment planning is which material to use, rather than whether to follow analogue or digital workflows. They then highlighted a number of recommended materials (Figure 8).

Metallic abutments in gold or noble alloys were recommended, because they can be screwed at 35Ncm. In restorations involving more than two implants, CAD/CAM Cr-Co should be used. Beyond the choice between digital or analogue, the most important factor to consider is the predicted time and cost of the procedure. �




The following report summarises the second paper presented during the Liaison for the best patient service. Analogue versus digital session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.


The same shift has occurred in laboratories, where work is carried out using CAD/CAM techniques, and the technician’s task is to give the ‘fi nal touches’ to the prostheses. With the introduction of so many digital techniques, the choice between analogue and digital is becoming less of a choice and more of an inevitability.

Liaison for the best patient service. Analogue versus digitalVincent FehmerEAO Congress Scientifi c Report; (3), 108–109, 2018.

Porcelain chippingMore and more often, patients are demanding metal-free prostheses. These kinds of restorations, however, are associated with a number of technical complications (Jung et al. 2012). Of these, screw loosening and porcelain chipping are the most frequent. Digital workfl ows can help us control this problem.

The conventional technique which involves manually layering porcelain generates air inclusions which may lead to failure under function. CAD/CAM procedures utilise an industrial fabrication process which prevents air bubbles and therefore makes crowns more resistant to chipping.

In single CAD/CAM restorations (without porcelain coating) various materials are available to be used. In multiple rehabilitations, however, only zirconia can be used as a substitute for porcelain fused to metal. There are currently no other options (Figure 1).

Digital impressions are ideal for partial restorations, because their precision has been proven. After intra-orally scanning the preparation, the technician can perform a digital wax-up in as short a timeframe as twenty minutes (instead of the two hours which would be required for an analogue wax-up).

The speaker recommended always having a physical model ready, so you can try the bridge and ‘go back to reality’. Monolithic zirconia restorations should be cemented on metallic abutments (TiBase). Monolithic zirconia has a higher grey value and these crowns have to be stained to achieve a suitable but mediocre aesthetic appearance. No chipping has been reported in these restorations, so good results can be achieved in posterior quadrants.

The question remains: do monolithic restorations have the same effi ciency, quality and cost, as conventional metal-ceramic restorations? To test the

fl exural strength of different options for abutments and monolithic crowns, an in vitro study recently compared the four options (Pitta et al. 2017):

� C1: customised titanium abutment with lithium disilicate cemented crown

� T1: TiBase interphase with zirconia abutment plus cemented lithium disilicate crown

� T2: TiBase interphase with zirconia abutment plus cemented hybrid crown

� T3: TiBase interphase with zirconia abutment plus cemented zirconia crown (Figure 2)

Figure 1

Figure 2


The authors of the study concluded that the zirconia mesio-abutments bonded to titanium bases appeared to be a stable combination when compared with customised titanium abutments (which still represent the gold-standard). Regarding the crown material, monolithic zirconia was revealed to be mechanically superior to the other crown materials.

Promising short-term results for the clinical behaviour of zirconia have been reported (Batson et al. 2014; Sulaiman et al. 2015; Spies et al. 2016). For a new material to be validated, however, it should have clinical results from an observational period lasting at least seven years.

It has also been found that monolithic zirconia can work well in a clinical environment and does not wear the antagonists, compared with other ceramics. The surface roughness of zirconia influenced the wear. After grinding and glazing, zirconia exhibited more wear than when polished (Preis et al. 2013; Janyavula et al. 2013; Stober et al. 2014).

At least in Switzerland, the laboratory cost of restorations is 40% lower when using zirconia. In summary, the only problem with zirconia is aesthetics, as it can only be stained or polished.

References

Batson ER, Cooper LF, Duqum I, Mendonça G. Clinical outcomes of three different crown systems with CAD/CAM technology. J Prosthet Dent. 2014 Oct;112(4):770–7.

Janyavula S, Lawson N, Cakir D, Beck P, Ramp LC, Burgess JO. The wear of polished and glazed zirconia against enamel. J Prosthet Dent. 2013 Jan;109(1):22–9.

Jung RE, Zembic A, Pjetursson BE, Zwahlen M, Thoma DS. Systematic review of the survival rate and the incidence of biological, technical, and aesthetic complications of single crowns on implants reported in longitudinal studies with a mean follow-up of 5 years. Clin Oral Implants Res. 2012 Oct;23 Suppl 6:2–21. doi: 10.1111/j.1600-0501.2012.02547.x.

Pitta J. Stability of zirconia mesio-abutments bonded to titanium bases restored with monolithic crowns. e-poster presented at EAO 26th annual meeting, Madrid 2017. EAO Online Library. Pitta J. Oct 6, 2017; 198734

Preis V, Weiser F, Handel G, Rosentritt M. Wear performance of monolithic dental ceramics with different surface treatments. Quintessence Int. 2013 May;44(5):393–405. doi: 10.3290/j.qi.a29151.

Spies BC, Patzelt SB, Vach K, Kohal RJ. Monolithic lithium-disilicate single crowns supported by zirconia oral implants: three-year results of a prospective cohort study. Clin Oral Implants Res. 2016 Sep;27(9):1160–8. doi: 10.1111/clr.12716. Epub 2015 Oct 27.

Stober T, Bermejo JL, Rammelsberg P, Schmitter M. Enamel wear caused by monolithic zirconia crowns after 6 months of clinical use. J Oral Rehabil. 2014 Apr;41(4):314–22. doi: 10.1111/joor.12139. Epub 2014 Jan 22.

Sulaiman TA, Abdulmajeed AA, Donovan TE, Ritter AV, Lassila LV, Vallittu PK, Närhi TO. Degree of conversion of dual-polymerizing cements light polymerized through monolithic zirconia of different thicknesses and types. J Prosthet Dent. 2015 Jul;114(1):103–8. doi: 10.1016/j.prosdent.2015.02.007. Epub 2015 Apr 14. �




The following report summarises the third paper presented during the Liaison for the best patient service. Analogue versus digital session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.


The same shift has occurred in laboratories, where work is carried out using CAD/CAM techniques, and the technician’s task is to give the ‘final touches’ to the prostheses. With the introduction of so many digital techniques, the choice between analogue and digital is becoming less of a choice and more of an inevitability.

Digital workflow in implants prosthodonticsGerman O. GallucciEAO Congress Scientific Report; (3), 110, 2018.

Digital technology is here to stay

3D radiology must always be performed after the prosthetic planning phase. When both files have been merged, a provisional can be made according to the implant position achieved using a surgical guide. Currently, we can go directly from planning the implant position to the final prosthesis without impressions and models.

But the extent to which digital implant technology is implemented in practice seems to be irregular1. Virtual planning is the most popular, whereas the use of guided surgery is limited to cases involving multiple implant. It is often the case that prostheses have to be finished using analogue methods in order to achieve a better resemblance to the natural tooth.

Digital workflows applied to patient care

In a case involving a missing lateral incisor, the speaker showed that by copying the contralateral tooth it is possible to perform a digital wax-up of the tooth which had to be replaced. The possibility of fully integrating the best anatomical position and the best prosthetic design is something which we did not have before. It is now possible (for example) to design the abutment with total control over margins, so that it does not impinge upon the bone and its proper emergence profile. The high coincidence between the planned position and the achieved position allows us to properly place the provisional fabricated beforehand. Ideal integration of the design (or digital wax-up) and the implant planning software is mandatory as a channel of communication between the technician and surgeon.

In complex cases, digital workflows can offer major advantages. Digital wax-ups which include labial support and incisal edge position are merged with the planned 3D implant position, providing

1 Data from Harvard School of Dental Medicine.

information about the screw-hole locations and the volume of the definitive prosthesis.

The accuracy of digital impressions has been documented in a recent in vitro study (Papaspyridakos et al. 2016). Therefore a digital impression can be made and then printed as a model for the metal to be worked (which is the only conventional step). Digital workflows can help us achieve more reproducible results in our treatments and prevent potential mistakes.

The speaker described the completely digital workflow which he and his team are currently developing to restore edentulous patients. As part of this workflow, the positions of mini-implants which will be used to pin the surgical template are planned first. Although not at the micro level, this procedure may have enough precision on a macro scale to be clinically reproducible. The mini-implants can also be used to support provisional restorations.

Concluding remarks

A straightforward digital workflow has not yet been defined. It can, however, be applied in a number of different ways, according to the patient’s demands and the preferences of the clinician’s team. But our final goal, and ultimate responsibility as clinicians, should be to never compromise on the quality of the results. Digital workflows must therefore add to (not subtract from) what we already know how to do well.

References

Papaspyridakos P, Gallucci GO, Chen CJ, Hanssen S, Naert I, Vandenberghe B. Digital versus conventional implant impressions for edentulous patients: accuracy outcomes. Clin Oral Implants Res. 2016 Apr;27(4):465–72. doi: 10.1111/clr.12567. Epub 2015 Feb 13. �




The following report summarises the chairperson’s introduction to the The biological and clinical keys for periodontal, bone and peri-implant regeneration session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

The biological and clinical keys for periodontal, bone and peri-implant regenerationMariano SanzEAO Congress Scientific Report; (3), 111, 2018.

The biological requirements for regeneration are the same for periodontal and bone tissues: blood supply, cells to differentiate, molecular mediators, and a scaffold for maintaining space. But a full understanding of intrinsic cellular mechanisms is still lacking: the extent of the interaction between immune cells and fibroblasts to modify cell phenotypes guiding the fate of the wound healing is not yet known.

Regeneration techniques currently being used are based on the ‘homing effect’ of the barriers or the ‘scaffolding effect’ of the grafts, which

either add or do not add biologic molecules. But an understanding of their full influence over tissue regeneration is still lacking. At the moment, treatment is dictated by the morphological classification of bone defects as defined by Benic and Hämmerle (Benic & Hämmerle. 2014).

References

Benic GI, Hämmerle CH. Horizontal bone augmentation by means of guided bone regeneration. Periodontol 2000. 2014 Oct;66(1):13-40. doi: 10.1111/prd.12039. �




The following report summarises the fi rst paper presented during the The biological and clinical keys for periodontal, bone and peri-implant regeneration session, at the EAO’s 26th annual Scientifi c Meeting in Madrid, 2017.

Periodontal regeneration: translating biologic concepts into clinical applicationPierpaolo CortelliniEAO Congress Scientifi c Report; (3), 112–114, 2018.

Periodontal regeneration is a well-documented technique with long-term results for saving teeth with advanced periodontal lesions. A systematic review and meta-analysis from the AAP Regeneration Workshop found that clinical outcomes could be stably maintained on a long-term basis, provided that a suitable oral hygiene programme was carried out (Kao et al. 2015). The speaker discussed a clinical study on 175 teeth with severe bony defects treated with guided tissue regeneration (GTR) and followed for a period of up to 16 years (8 ± 3.4). The study reported a 96% ten-year survival rate and stable clinical attachment levels over time. Patients with tooth loss were smokers; all but one did not adhere to the supportive periodontal programme (Cortellini & Tonetti. 2004). The speaker also described a recent 20-year randomised clinical trial – perhaps the longest ever published on periodontal regeneration – which obtained a 100% survival rate in well-maintained patients (Cortellini et al. 2017).

The speaker also described his fi rst clinical case, which, thirty years after being treated with GTR continues to maintain its initial clinical outcome (Pini Prato & Cortellini. 2016).

Layout for optimal regeneration

The speaker identifi ed fi ve factors for ensuring optimal regeneration:

� initial prognosis which must be therapeutically improved

� controlled local factors � selection of suitable treatment strategy � application of sophisticated surgical techniques � meticulous supportive periodontal therapy (SPT)

The periodontal prognosis must be improved by initial treatment before any regenerative procedures can be performed. Then, by the time of the re-evaluation check, all local, behavioural and systemic factors should be under control (Figures 1–2). At that point, it is mandatory to record the anatomy of the defect, because the treatment approach must be selected according to the classifi cation of the defect morphology (Figure 3).

The speaker outlined three important considerations for controlling local factors, which will determine the treatment decision-tree (Figure 4):

Diagnosis InitialPrognosis

Modified Prognosis

Main aim of cause – related therapy.....

Cortellini 2017

Figure 1

Localfactors

PlaqueFMPS < 15%

InfectionFMBS < 15%

Behaviouralfactors

Compliance

Smoke< 10 / die

Systemicfactors

Stress

Diseases(diabetes)

Modified prognosis

Optimalbackground for regeneration

Re-evaluation criteria

Cortellini 2017

Figure 2

Infrabony pockets

Osseous Defects

Suprabonyand craters

Intrabony Interradicular

1,2,3 wall Class I,II,III

Periodontal Regeneration

NO Periodontal

Regeneration

? Periodontal

Regeneration

Cortellini 2017

Figure 3

Cortellini 2017

Figure 4


� endodontic condition: vital teeth should remain vital, and non-vital teeth (or those with the apex involved in the lesion) should be treated endodontically. Endodontic treatments which have not been performed properly should be re-done

� local contamination: one or two weeks before GTR, the pocket should be explored; if bleeding is present, gentle root planning and a local antimicrobial should be applied

� tooth mobility: the mobility of the tooth may also disturb the clot; splinting is highly recommended if second- or third-degree mobility is present

Selecting the treatment approach

There are several tools with proven histological and clinical effi cacy: regenerative materials; demineralised freeze-dried bone allografts (DFDBA); barriers; enamel matrix derivative (EMD); combination and growth factors. Each have are associated with a number of additional benefi ts, most of which have been assessed in systematic reviews.

There are, however, three key principles to observe in regeneration procedures:

� space maintenance � blood clot stability � site protection

All these depend on the morphology of the defect. In self-containing defects (most of which are three-wall defects), there is no need for biomaterials to enhance space and blood clot stability. On the other hand, in non-containing defects, barriers and grafting materials are needed.

The speaker described a surgical technique which he and his group have developed over a number of years:

� papilla preservation fl ap (PPF): aims to preserve interdental soft tissue to provide primary closure and is designed to be used as a membrane

� minimally invasive surgical technique (MIST): after the introduction of microsurgery, reduced fl ap extensions were proposed to gain minimal access to the defect without the use of membranes

� modifi ed MIST (M-MIST): only a triangular buccal fl ap is elevated to maintain the papilla and the work is done through a small window

Comparing the average performance of these fl aps without regenerative materials on intra-bony defects of (about) 5mm, the M-MIST approach has been shown to achieve major clinical attachment level (CAL) gain after one year (Figures 5–6).

Interestingly, when studying the additional benefi ts of EMD in combination with these fl aps, no additional benefi ts were observed with the M-MIST approach, highlighting the potential which this approach has by itself (Figures 7–8).

Treatment strategy

The strategy for periodontal regeneration is based on a combination of three factors:

� regenerative products � fl ap designs � instruments and materials

0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

1-year CAL Gain: performance of various flaps

Ribeiro et al 2011 Cortellini & Tonetti 2011

PPF (Syst Rev) MIST (RCT) M-MIST (RCT)Flap (Syst Rev)

Graziani et al 2012

1,6mm 2,5mm

Graziani et al 2012

2,8mm 4,1mm

5mmCortellini 2017

Figure 5

0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

Ribeiro et al 2011 Cortellini & Tonetti 2011

PPF (Syst Rev) MIST (RCT) M-MIST (RCT)Flap (Syst Rev)

Graziani et al 2012

1,6mm 2,5mm

Graziani et al 2012

2,8mm 4,1mm

5mm1-year CAL Gain: performance of various flaps Cortellini 2017

Figure 6

1-year CAL Gain: Controlled Studies with EMD

0

0,5

1

1,5

2

2,5

3

3,5

4

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PPF MIST M-MIST

FlapFlap + EMD

Tonetti et al 2002 Ribeiro et al 2011 Cortellini & Tonetti 2011

3.1±1.52.5±1.5 2.8±1.23.0±1.9 4.1±1.4 4.1±1.2

P< 0.01 P> 0.05 P= 0.4

Cortellini 2017

Figure 7

0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

PPF MIST M-MIST

FlapFlap + EMD

Tonetti et al 2002 Ribeiro et al 2011 Cortellini & Tonetti 2011

3.1±1.52.5±1.5 2.8±1.2 3.0±1.9 4.1±1.4 4.1±1.2

P< 0.01 P> 0.05 P= 0.4

1-year CAL Gain: Controlled Studies with EMD Cortellini 2017

Figure 8


With the proper selection of the above, a wide range of periodontal defects can be treated successfully (Figure 9). To demonstrate this, the speaker presented a number of clinical cases.

Main concepts

The main concepts discussed – along with their evidence-base – are summarised in Figure 10.

References

Cortellini P, Tonetti MS. Long-term tooth survival following regenerative treatment of intrabony defects. J Periodontol 2004 May;75(5):672–8.

Cortellini P, Buti J, Pini Prato G, Tonetti MS. Periodontal regeneration compared with access fl ap surgery in human intra-bony defects 20-year follow-up of a randomized clinical trial: tooth retention, periodontitis recurrence and costs. J Clin Periodontol. 2017 Jan;44(1):58–66. doi: 10.1111/jcpe.12638. Epub 2016 Nov 22.

Kao RT, Nares S, Reynolds MA. Periodontal regeneration – intrabony defects: a systematic review from the AAP Regeneration Workshop. J Periodontol. 2015 Feb;86(2 Suppl):S77–104. doi: 10.1902/jop.2015.130685. Epub 2014 Sep 12.

Pini Prato G, Cortellini P. Thirty-year stability after regeneration of a deep intrabony defect: a case report. J Clin Periodontol 2016 Oct;43(10):857–62. doi: 10.1111/jcpe.12587. Epub 2016 Aug 9. �



Coronal 3rd

Mid 3rd

Apical 3rd

Monorooted

Coronal 3rd

Mid 3rd

Apical 3rd

Coronal 3rd

Mid 3rd

Apical 3rd

Multirooted

Cortellini 2017

Figure 9


Backbone for regeneration is control of patient and site related factors

TYPE IRandomized Clinical TrialsTYPE II Prospective studies

Periodontal regeneration can be predictably achieved in intrabony defects from shallow to very deep


Outcomes obtained can be maintaned over time in patients with good oral hygiene, compliant with SPC, and non smokers


Cortellini 2017

Figure 10


The following report summarises the second paper presented during the The biological and clinical keys for periodontal, bone and peri-implant regeneration session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

The biological and clinical keys for bone regenerationChristoph HämmerleEAO Congress Scientific Report; (3), 115–116, 2018.

Guided bone regeneration (GBR) procedures are routinely carried out in daily practice, but there are several critical questions which still need to be answered:

� to what extent do soft and hard tissues participate in the final augmentation?

� is there need for bone regeneration in small defects?

� further methods for enhancing success and predictability?

� long-term outcomes of GBR procedures? � long-term fate of buccal contouring?

Effect of hard/soft tissue augmentation

Although large inter-individual variations were observed, a prospective cohort study evaluating changes in peri-implant volume found an average increase of 1.27mm. This figure was composed of 0.7 ± 0.47mm for GBR (57%), and 0.6 ± 0.53mm for soft tissue grafts (STG) (43%). This augmented volume remained stable for one year after crown insertion (Schneider et al. 2011). Therefore, it can be concluded that both GBR and STG seem to contribute significantly to augmented volume.

Is GBR needed in small defects?

A recently published randomised controlled clinical trial compared buccal dehiscences measuring ≦ 5mm which were treated with GBR or with spontaneous healing. The differences between the two were statistically significant both in initial bone loss at re-entry six months after GBR and in the 18-month follow-up (Jung et al. 2016). It can be concluded that GBR performs better in small bone defects than spontaneous healing does.

Are GBR results stable in the long-term?

An observational study was conducted on 58 patients with 222 implants placed either with GBR (using resorbable or non-resorbable membranes) or in natural bone. The average follow-up examination period was at 12.5 years (between 12 to 14). The authors found no differences in survival rates nor in the clinical and radiographical assessment

between the three groups, and concluded that GBR procedures may be considered safe and predictable therapies for long-term performance of implants (Jung et al. 2013).

Similar results have been reported by a 15-year observational study comparing implants placed with GBR versus implants in natural bone. Buccal marginal bone and mucosa levels and buccal bone thickness were measured, as well as implant survival and clinical parameters like peri-implant pocket depth (PPD) and bleeding on probing (BoP). No significant differences were observed in the 15-year results (Benic et al. 2017).

Overall conclusions

� both hard and soft tissue augmentation procedures can significantly contribute to the facial tissue volume at implant sites (evidence type II)

� GBR is a successful method for regenerating smaller defects also at aesthetic sites (evidence type I)

� stable membranes allow better bone regeneration at the implant shoulders

� DDBM blocks maintained mineralised tissue volumes at the implant shoulder to a higher degree than DBBM particulates (evidence type I)

� short-term results of tissue augmentation regarding implant survival and buccal tissue volume are also stable long-term (evidence type I)

References

Benic GI, Bernasconi M, Jung RE, Hämmerle CH. Clinical and radiographic intra-subject comparison of implants placed with or without guided bone regeneration: 15-year results. J Clin Periodontol. 2017 Mar;44(3):315–325.

Jung RE, Grohmann P, Sailer I, Steinhart YN, Fehér A, Hämmerle C, Strub JR, Kohal R. Evaluation of a one-piece ceramic implant used for single-tooth replacement and three-unit fixed partial dentures: a prospective cohort clinical trial. Clin Oral Implants Res. 2016 Jul;27(7):751–61.


Jung RE, Fenner N, Hämmerle CH, Zitzmann NU. Long-term outcome of implants placed with guided bone regeneration (GBR) using resorbable and non-resorbable membranes after 12–14 years. Clin Oral Implants Res. 2013 Oct;24(10):1065–73.

Schneider D, Grunder U, Ender A, Hämmerle CH, Jung RE. Volume gain and stability of peri-implant tissue following bone and soft tissue augmentation: 1-year results from a prospective cohort study. Clin Oral Implants Res. 2011 Jan;22(1):28–37. �




The following report summarises the third paper presented during the The biological and clinical keys for periodontal, bone and peri-implant regeneration session, at the EAO’s 26th annual Scientific Meeting in Madrid, 2017.

The biological and clinical keys for peri-implant regenerationJuan BlancoEAO Congress Scientific Report; (3), 117–119, 2018.

Can we treat peri-implantitis lesions?Peri-implantitis is an aggressive infection and according to the literature has no standard treatment protocol (although surgical intervention is currently the most common approach). Biofilm formation is highly influenced by implant surface characteristics; surface debridement and cleaning are also key elements.

The standard goal of treatment is to achieve an inactive pocket measuring ≦ 5mm and a stable peri-implant condition with no further bone loss (Heitz-Mayfield at al. 2014; Heitz-Mayfield & Mombelli. 2014). But shouldn’t bone regeneration and even re-osseointegration be included in our treatment goal? At the least, we have to decide whether to treat (explant) in each particular case.

Is the current treatment protocol predictable?Among the current proposed techniques for treating peri-implantitis, there are three clinical studies which have fulfilled success criteria in 84–100% of the patients involved and obtained an average bone gain of 2.5mm (1.7–3.4mm), and average probing depth reduction of 3.7mm (2.7–5.3mm) in follow-ups over 12–90 months (Roccuzzo et al. 2011; Froum et al. 2012; Roos-Jansåker et al. 2007).

The three groups used the same surgical protocol:

1. Raising a full thickness flap2. Removing granulation tissue3. Mechanical debridement with plastic or titanium

curettes4. Surface decontamination5. Regeneration6. Connective tissue graft (when keratinised mucosa

is lacking)7. Suturing and non-submerged healing

There were some differences between the three studies in steps 4 and 5. During surface decontamination, there are a number of diverging options, including: chlorhexidine, peroxide, air-powder abrasive and saline, and tetracycline. However, there is no general consensus regarding which is best. During step 5 (regeneration), there are also various materials which can be used: DBBM (deproteinised bovine bone mineral) with 10%

collagen; Emdogain with DBBM or allograft mixed with PDGF; bone substitutes with blood and a resorbable membrane or without membrane.

The long-term results of the three studies (Roccuzzo et al. 2017; Froum et al. 2015; Roos-Jansåker et al. 2014) allow us to draw several conclusions:

� complete filling of peri-implant defects is not fully predictable

� implant surface matters: better results were achieved with SLA (sandblasted, large grit, acid-etched) implants

� 1.5–15% of implants may be lost � 16–31% of cases may have to be re-treated � membrane exposures may reach up to 43.8%

A recent systematic review on treatment outcomes of peri-implantitis (including 18 articles for meta-analysis) found a weighted mean radiological bone level fill of 1.97mm in a 12-month follow-up (Daugela et al. 2016).

What are the key factors influencing results?One of the key factors is implant surface decontamination. This is because bone growth is not possible on an infected surface. Up to now, heterogeneous results have been obtained from the literature, suggesting that inflammation removal is possible but re-osseointegration is unlikely. No method seems to be superior (Claffey et al. 2008; Renvert et al. 2012).

The speaker described a preclinical study which he and his team performed in the dog model comparing three decontamination protocols with a non-treated control group (Figure 1). All three protocols

Figure 1

1

Ti-brush+

NaClO 0,1%+

ClHX 0,2%

Ti-brush+

ClHX 0,2%

US+

ClHX 0,2%No Treatment


performed signifi cantly better than the control: the Ti-brush method was better than ultrasound, and no differences were reported when hypochlorite solution was added to the Ti-brush method (Carral et al. 2016).

Another key factor to consider is the confi guration of the bone defect according to the classifi cation system defi ned by Schwarz and colleagues (Schwarz et al. 2010) as supracrestal (type II) or infra-bony (type I) with fi ve subtypes (a–e) (Figure 2). As in other types of regeneration: the more defect walls, the better prognosis. In narrower confi gurations, however, access to the bottom of the defect may be diffi cult and implant surface decontamination almost impossible to be performed properly.

Regarding fi ller material, the biomaterial most frequently used is bovine-derived xenograft with or without collagen membrane (Daugela et al. 2016). The speaker stated that his group is now involved in an experimental study in the dog model to explore the value of adding rhBMP-2. As yet, the results do not show signifi cant differences (Sanz-Esporrín et al. In preparation).

The immediate post-surgical complications must also be taken into account, as the studies reported membrane exposure rates between 18% and 87.6%, with fewer exposures associated with a submerged approach and decreased regeneration in the presence of such complications (Roos-Jansåker et al. 2007 and 2011; Matarasso et al. 2014).

Finally, the literature comparing submerged with non-submerged healing is rather scarce. The speaker stated that the choice between the two depends on the defect morphology.

Conclusion

Before trying to perform a regenerative procedure, a full-mouth disinfection must be carried out. Patient compliance is also an important factor, and must be determined before treatment begins. During the surgical phase, clinicians should follow the surgical rules and choose a decontamination method which is as simple as possible. When selecting a fi lling material, the morphology of the defect must be considered carefully. It is still uncertain whether a submerged or non-submerged approach is better. The suture technique must be passive. Supportive peri-implant therapy every 3–6 months is mandatory. It is also important to keep researching to stay abreast of the current literature.

References

Carral C, Muñoz F, Permuy M, Liñares A, Dard M, Blanco J. Mechanical and chemical implant decontamination in surgical peri-implantitis treatment: preclinical “in vivo” study. J Clin Periodontol. 2016 Aug;43(8):694–701. doi: 10.1111/jcpe.12566. Epub 2016 Jun 13.

Claffey N, Clarke E, Polyzois I, Renvert S. Surgical treatment of peri-implantitis. J Clin Periodontol. 2008 Sep;35(8 Suppl):316–32. doi: 10.1111/j.1600-051X.2008.01277.x.

Daugela P, Cicciù M, Saulacic N. Surgical Regenerative Treatments for Peri-Implantitis: Meta-analysis of Recent Findings in a Systematic Literature Review. J Oral Maxillofac Res. 2016 Sep 9;7(3):e15.

Froum SJ, Froum SH, Rosen PS. Successful management of peri-implantitis with a regenerative approach: a consecutive series of 51 treated implants with 3- to 7.5-year follow-up. Int J Periodontics Restorative Dent. 2012 Feb;32(1):11–20.

Froum SJ, Froum SH, Rosen PS. A Regenerative Approach to the Successful Treatment of Peri-implantitis: A Consecutive Series of 170 Implants in 100 Patients with 2- to 10-Year Follow-up. Int J Periodontics Restorative Dent. 2015 Nov-Dec;35(6):857–63. doi: 10.11607/prd.2571.

Heitz-Mayfi eld LJ, Needleman I, Salvi GE, Pjetursson BE. Consensus statements and clinical recommendations for prevention and management of biologic and technical implant complications. Int J Oral Maxillofac Implants. 2014;29 Suppl:346–50. doi: 10.11607/jomi.2013.g5.

Heitz-Mayfi eld LJ, Mombelli A. The therapy of peri-implantitis: a systematic review. Int J Oral Maxillofac Implants. 2014;29 Suppl:325–45. doi: 10.11607/jomi.2014suppl.g5.3.

Matarasso S, Iorio Siciliano V, Aglietta M, Andreuccetti G, Salvi GE. Clinical and radiographic outcomes of a combined resective and regenerative approach in the treatment of peri-implantitis: a prospective case series. Clin Oral Implants Res. 2014 Jul;25(7):761–7. doi: 10.1111/clr.12183. Epub 2013 May 8.

Renvert S, Polyzois I, Claffey N. Surgical therapy for the control of peri-implantitis. Clin Oral Implants Res. 2012 Oct;23 Suppl 6:84–94. doi: 10.1111/j.1600-0501.2012.02554.x.

Roccuzzo M, Bonino F, Bonino L, Dalmasso P. Surgical therapy of peri-implantitis lesions by means of a bovine-derived xenograft: comparative results of a prospective study on two different implant surfaces. J Clin Periodontol. 2011 Aug;38(8):738–45. doi: 10.1111/j.1600-051X.2011.01742.x. Epub 2011 Jun 2.

Roos-Jansåker AM, Persson GR, Lindahl C, Renvert S. Surgical treatment of peri-implantitis using a bone substitute with or without a resorbable membrane: a 5-year follow-up. J Clin Periodontol. 2014 Nov;41(11):1108–14. doi: 10.1111/jcpe.12308. Epub 2014 Oct 17.

Roos-Jansåker AM, Renvert H, Lindahl C, Renvert S. Submerged healing following surgical treatment of peri-implantitis: a case series. J Clin Periodontol. 2007 Aug;34(8):723–7. Epub 2007 May 29.

Figure 2

Defectstype I

a b

c d e

Defectstype II


Roos-Jansåker AM, Lindahl C, Persson GR, Renvert S. Long-term stability of surgical bone regenerative procedures of peri-implantitis lesions in a prospective case-control study over 3 years. J Clin Periodontol. 2011 Jun;38(6):590–7. doi: 10.1111/j.1600-051X.2011.01729.x. Epub 2011 Apr 13.

Roccuzzo M, Pittoni D, Roccuzzo A, Charrier L, Dalmasso P. Surgical treatment of peri-implantitis intrabony lesions by means of deproteinized bovine bone mineral with 10% collagen: 7-year-results. Clin Oral Implants Res. 2017 Dec;28(12):1577–1583. doi: 10.1111/clr.13028. Epub 2017 Jun 18.

Schwarz F, Sahm N, Schwarz K, Becker J. Impact of defect configuration on the clinical outcome following surgical regenerative therapy of peri-implantitis. J Clin Periodontol. 2010 May;37(5):449–55. doi: 10.1111/j.1600-051X.2010.01540.x. Epub 2010 Mar 24. �



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