Ceramics in fixed prosthodontics considerations for use in dental practice

Karl Lyons!Department of Oral Rehabilitation!

Faculty of Dentistry

Ceramics in Fixed Prosthodon2cs Considera2ons for use in Dental Prac2ce

1

Karl Lyons

2

Presentation Outline•  Ceramics in dentistry •  Types of ceramics •  Clinical indications and uses •  Case considerations

•  Preparation designs •  Fitting and adjusting •  Cementation

•  Longevity and causes of failure •  Alternatives •  Summary

3

Ceramics in Dentistry

Why?

All Ceramic Crowns

Zirconium Vs

Leucite Reinforced

Vs

Metal-ceramic

Light Dynamics in Natural Teeth

Tooth colours are produced by the colour of the dentine and pulp reflecting through the enamel layer which is influenced by the amount of demineralisation

Raptis et al. 2006

The Effect of Light Transmission Four crowns placed on tooth 11 Which two are PFM and which two are All-ceramic crowns?

In-Ceram Spinell IPS Empress

PFM PFM (with porcelain shoulder)

Note how light is blocked by the metal copings

Raptis et al. 2006

Light Transmission

Charles Land •  Invented dental porcelain in 1886 •  Granted Patent 1887 •  Platinum foil matrix

Land CH (1903) Porcelain dental art: No II. Dental Cosmos 45:615-620 John McLean & TJ Hughes •  Replaced metal reinforcement with Alumina (Al2O3) to develop first all-ceramic core The reinforcement of dental porcelain with ceramic oxides. (1965) BDJ 119(6):251-267

Evolution of Ceramic Crowns

Types of All-ceramic Monolithic crowns (1 layer)

Bilayered crowns (2 layers - core & veneer)

Eg: •  Feldspathic –CAD/CAM

blocks •  Leucite reinforced –

Empress I •  Lithium Disilicate – emax

Press or CAD •  Zirconia (recently introduced)

Eg: •  Lithium Disilicate •  Glass-infiltrated – In-Ceram Spinell •  Alumina •  Zirconia

Three main types of ceramics in dentistry 11.  Predominantly glass

•  Veneering porcelains for PFM and all-ceramics

•  Most translucent – high aesthetics

2.  Particle-filled glass (Glass-ceramics) i.  High glass content

•  Lost wax system (Dicor) [no longer available]

•  Machinable feldspar-based ceramic (Vita Mark II blocks)

•  Heat-pressed Leucite reinforced (Empress I)

(Kelly 2008)

Three main types of ceramics in dentistry 2

2.  Particle-filled glass (Glass-ceramics)

ii.  Low glass content •  Heat-pressed or CAD/CAM Lithium

Disilicate (IPS emax) •  Slip-cast or CAD/CAM Glass-infiltrated

alumina (In-Ceram)

3.  Polycrystalline (Ceramic oxides) i.  Alumina Oxide (Procera Alumina)

ii.  Zirconia (3mol%Y-TZP) (Procera

Zirconia)

Commercially Available Dental Ceramics

Flexural Strength of CeramicsFr

actu

re To

ughn

ess

[KIC

(MPa

.m1/

2 )]

Flexural Strength (MPa)

Methods for Reinforcing Porcelain

Metal-Oxides •  Aluminium Oxide •  Magnesium-Alumina Spinel •  Zirconium Oxide

Leucite Lithium Disilicate •  Dispersion strengthening •  Phase transformation toughening

VITABLOCS® Materials

VITABLOCS Block Restoration Indication

Mark II Inlays, onlays,

anterior/posterior crown and

veneer

TriLuxe Anterior/posterior

crown and veneer

TriLuxe forte Anterior/posterior

crown and veneer

RealLife

Anterior/posterior crown/ veneer

for natural aesthetics

Structural Ceramics•  Lithium disilicate

•  Excellent translucency and aesthetics •  Inlays, onlays, veneers, crowns

•  In-Ceram Spinel •  Excellent translucency and aesthetics •  Anterior crown substructure

Structural Ceramics•  In-Ceram Alumina

•  Good combination of strength and aesthetics

•  Substructure for anterior crowns and 3-unit bridges

•  In-Ceram Zirconia •  Very good strength •  Substructure for anterior and posterior

crowns and 3-unit bridges

Structural Ceramics

•  In-Ceram AL •  Very good strength •  Substructure for anterior and 3-unit

bridges and posterior crowns

•  In-Ceram YZ •  Excellent strength •  Substructure for anterior and

posterior crowns and multi-unit bridges

Alumina and Zirconia

•  The increase in crystalline content in alumina and zirconia has: •  Improved the mechanical properties allowing

all-ceramic crowns and bridges •  Is hard to machine and resistant to etching

so resin bonding is a challenge

Zirconia

Zirconia

Note the difference in shrinkage between pre-sintered and sintered substructure.

Zirconia

Images compliments Vita Zahnfabrik

Procera

Overview of VITA In-Ceram® Ceramics

Vita EnamicCAD/CAM Hybrid Ceramic

product description from Vita•  For the first time, this innovative hybrid materials

combines enormous strength with exceptional elasticity •  As a result, the material is perfectly suited for crown

restorations and moreover allows to achieve reduced wall thicknesses for minimally invasive restorations

•  Additionally, VITA ENAMIC excels by utmost reliability and precise and accurate milled restorations featuring high edge stability

•  This tooth-colored hybrid material also exhibits tooth-like material properties and produces highly esthetic results thanks to its excellent translucency

Ceramic network + Polymer network = Hybrid ceramic

VITA ENAMIC: Dental hybrid ceramic!

=!polymer-reinforced ceramic network

Reinforced materials: (e.g. carbon, reinforced concrete)!

= steel reinforced cement

Common Ceramic Core MaterialsAmorphous glass - Veneering porcelains Glass ceramics (reinforced by crystalline phases)

• Leucite reinforced - Empress I • Lithium disilicate - Empress II • Magnesium aluminium oxide - In-Ceram Spinnell

• Feldspathic Glass - Vita Mark II Blocks Glass infiltrated mixtures

• In-Ceram alumina

• In-Ceram zirconia Polycrystalline

• Alumina - Procera • Zirconia - Lava, Everest, Cercon, Procera, Zeno, Ivoclar etc

1.  Amorphous glass – Vita Mark II 2.  Crystalline glass ceramics

(reinforced by crystalline phases) 1.  Leucite reinforced - Empress I 2.  Lithium disilicate - Empress II

3.  Glass infiltrated mixture 1.  Magnesium Aluminium Oxide -

Spinell 2.  InCeram alumina 3.  InCeram zirconia

4.  Polycrystalline 1.  Alumina - Procera 2.  Zirconia – Lava

All-Ceramic Material Type! Aesthetic Properties! Applications!

Feldspathic Glass (predominantly glass)

Intrinsically tooth coloured

Anterior veneers & crowns

Can be stained & glazed

Crystalline Ceramics (particle-filled glass - high

glass content)

Intrinsically tooth coloured

Anterior veneers & crowns

Can be stained & glazed

Glass Infiltrated Mixtures (particle-filled glass – low

glass content)

Core material Core can be pigmented

Anterior and posterior crowns

Are veneered with porcelain

Polycrystalline Ceramics (no glass content)

Core material Core can be pigmented

Anterior and posterior crowns & bridges Are veneered with

porcelain

10!

8!

6!

4!

2!

0!200! 400! 600! 800! 1000!0!

Frac

ture

Toug

hnes

s (M

Pa m

1/2 )

Bending Strength (MPa) Filser et al., Quintessenz Zahntechnik 28, 1, 48-60 (2002)

Empress 1

Dicor MGC In-Ceram Spinell

In-Ceram Zirconia

In-Ceram Alumina

Zirconium oxide e.g. Zeno ZR

IPS Empress 2 Glass Ceramics

Crystalline Glass Ceramics

Aluminium Oxide

Zirconia

Vita Mark II

Aluminium Oxide Procera

Anterior Crown Anterior Bridge All Restorations

Types of Ceramic Crowns Sintered porcelain •  Feldspathic, Alumina or Leucite-reinforced Slip cast glass infused ceramic •  In-Ceram - Alumina, Spinell or Zirconia Heat pressed ceramic - Leucite or Lithium disilicate •  IPS Empress, IPS Empress 2 •  Pentron OPC, Pentron OPC 3G •  Finesse All-Ceramic Machined glass ceramic (eg CEREC 3, CEREC inLab) •  Chair-side - VitaBlocs Mark II, ProCAD •  Lab-milled - In-Ceram 2000, IPS e.max CAD, IPS Empress CAD Machined densely sintered ceramic - Alumina, Zirconia •  Procera, Lava, Everest, e.max ZirCAD

Sintered Porcelain Crowns

•  Feldspathic, Alumina & Leucite-Reinforced

•  Flexural Strengths •  55 – 75MPa (feldspar) •  90 – 120MPa (alumina) •  105 – 160MPa (leucite)

•  Clinical Survival Rates •  Aluminous 73% over 5 years •  Leucite

•  Anteriors 97% over 3 years •  Posteriors 76% over 5 years

Hankinson & Cappetta 1994; Etemadi & Smales 2006

Sintered Porcelain Crowns

Slip-Cast Glass Infused Ceramics

•  In-Ceram: Alumina, Spinell & Zirconia

•  Flexural strengths • ~400MPa (Spinell) • ~500MPa (Alumina) • ~600MPa (Zirconia)

•  Clinical survival rates • In-Ceram Alumina & Spinell = 92% to 100% over 5 yrs • In-Ceram Zirconia = 3-unit FPD 95% over 3 yrs

Wasserman et al. 2006

Slip-Cast Glass Infused Ceramics

Slip Casting Technique


Heat-Pressed Ceramic Crowns

IPS Empress, IPS Empress 2, Pentron OPC, Pentron OPC 3G, Finesse All-Ceramic •  Flexural strengths - Leucite, Lithium disilicate • 140 – 200MPa (Leucite) • 350 – 450MPa (Li2O•2SiO2)

•  Clinical survival rates

•  Leucite 92% to 99% for anteriors over 3.5 years •  Lithium disilicate 100% over 50 months (n=27)

Chadwick 2004; Marquadt 2006

Heat-Pressed Ceramic Crowns

IPS Empress

Machined Glass-Ceramic Crowns

eg CEREC 3, CEREC inLab

•  Chair-side - VitaBlocs Mark II, ProCAD:

•  Lab-milled - In-Ceram 2000, IPS e.max CAD, IPS Empress CAD:

• Industrially fabricated - stronger and more reliable • Clinical survival rates • Feldspathic-milled = 94% over 5 years (n=17, anterior)

Bindl & Mormann 2004

Machined Glass-Ceramic Crowns

Machined Densely Sintered Crowns

Machined Densely Sintered Crowns •  Alumina, Zirconia, Zircon •  Procera, Lava, Everest, e.max ZirCAD

•  Flexural strengths •  600MPa (Alumina) •  700 - 820MPa (Zircon) •  850 - 1050MPa (Zirconia)

•  Clinical survival rates •  Procera Alumina 92% at 10 years •  Zirconia FPDs 100% of frameworks at 3 years

Odman & Andersson 2001; Sailer et al. 2006

In-Ceram AluminaEmpress2

Empress

Summary of Ceramics

Systematic Review Goodacre et al 2003!

Mean fracture rate for all-ceramic crowns increases as you move posteriorly

Anteriors 3% Premolars 7% Molars 21%

This review did not distinguish between: •  fracture modes (core or veneer chipping) •  or types of ceramic systems

Systematic ReviewPjetursson et al 2007 - All-ceramic vs PFM crowns 5yr survival rates:

PFM 95.6% All-ceramic 93.3%

85% of all-ceramic crowns failures due to core fracture Chipping usually repairable Anteriors: All-ceramics = PFM Posteriors: Material dependent

ü  Alumina oxide 95% ü  Reinforced glass ceramics (Empress) 94% ²  In-Ceram 90% ²  Glass-ceramics (Dicor) 85%

Systematic ReviewWang et al 2012 - All-ceramic single crowns

5 yr Fracture rate: (veneer + core) all systems Overall 7.7% Posteriors 10% Anterior teeth 4.4%

Core fracture: Overall 7.2% Posteriors 9.5% Anteriors 3.9%

Veneer chipping: Overall 3% Molars 3% Premolars 1.5% Canines 2.5% Incisors 2%

No clear difference found

Statistically significant

Statistically significant

Systematic ReviewSailer et al 2007 - fixed partial dentures

5yr survival rates: Metal-ceramic FPDs 94.4% All-ceramic FPDs 88.6%

Frequency of: core # veneer # Metal-ceramic FPDs 1.6% 2.9% All-ceramic FPDs 6.5% 13.6%

Mainly Lithium disilicate and In-Ceram Rare in zirconia FPD

Annual rate: Zirconia 1.98 – 12.2 Empress/emaxP 0.83 – 1.55 In-Ceram no chipping reported

Recommended IndicationsClass 1 Ceramics

•  Aesthetic ceramic for coverage of a metal or ceramic subsurface

and/or •  Aesthetic ceramic for single-unit anterior,

veneers, inlays, or onlays

Example IPS Empress, IPS e.max Ceram (Ivoclar) Della Bona, 2009


•  Aesthetic ceramic for adhesively cemented, single unit, anterior or posterior prostheses

and/or •  Adhesively cemented, substructure ceramic

for single-unit anterior or posterior prostheses

Example IPS Empress (Ivoclar), Cerec MkII (Vita) Della Bona, 2009


•  Aesthetic ceramic for non-adhesively cemented, single-unit, anterior or posterior prostheses

Example IPS e.max Press or CAD (Ivoclar) Della Bona, 2009


•  Substructure ceramic for non-adhesively cemented, single-unit, anterior or posterior prostheses

and/or •  Substructure ceramic for three-unit

prostheses not including molar restoration •  Example IPS Empress 2, (Ivoclar), Cerec MkII (Vita)

Della Bona, 2009

Factors that Influence Ceramics

•  Ceramics are susceptible to chemical corrosion and fatigue mechanisms

•  This reduces their lifetime •  Unfavourable oral conditions include:

•  Chewing forces from 100-700 N •  Moist environment at 37ºC •  Small contact area; stresses generated 3.5-890

MPa Della Bona, 2009

Survival of CeramicsTo improve mechanical behaviour of ceramics •  Select the ceramic considering location

•  Consider substructure similar to metal for PFM •  Minimise surface roughness

•  Rougher surfaces have more cracks so need fewer cycles of stress to fail

•  Chemical interaction between ceramic (crack tips) and environment (water) results in accelerated crack growth due to stress corrosion

Della Bona, 2009

Considerations in Fixed Prosthodontics

Considerations in Fixed Prosthodontics 3

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Crown MarginThe image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.

Length of Edentulous Span 1The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.

Length of Edentulous Span 2


Minimum occlusogingival and buccolingual connector dimensions as a function of position of the bridge

connector and occlusal forces!

Ceramic Crown Form


Ceramic Crown Form


Minimum 9mm3 Tooth Preparation

Summary

Bonding Ceramic Crowns•  The crystalline content in alumina and zirconia

is resistant to etching so bonding is a challenge •  Silica coating systems (eg Rocatec and Cojet,

3M ESPE) creates a silica layer •  High-speed surface impact of silica-modified

alumina particles promotes resin bonding by: •  Rough surface allowing micromechanical bonding

to resin •  Promotes a chemical bond between the silanated

silica coated ceramic and the resin bond material

Bonding Strategies to Teeth and Restorative Materials

Commercially Available Dental Ceramics

Material properties: StrengthStrength is probably the most advertised property in the dental literature.

0 200 400 600 800 1000 1200

Zirconia

Aluminium Oxide

Lithium Disilicate - Hot Press

Lithium Disilicate - CAD/CAM

Magnesium Alliminium Oxide - Spinell

Leucite Reinforced

Feldspathic Glass

Zirconia Aluminium Oxide

Lithium Disilicate - Hot Press

Lithium Disilicate - CAD/CAM

Magnesium Alliminium

Oxide - Spinell

Leucite Reinforced

Feldspathic Glass

Series1 1100 620 470 350 400 175 80

Flexural Strength of All-Ceramic Materials in MPa

Series1

Shinogaya et al, 2001, Clin Oral Invest 5:63-68

Failure Classifica2onBiological failures

•  Secondary caries Aesthetic failure

•  Restoration contours, value, hue, chroma Mechanical failures

•  Cracking •  Chipping fracture (veneering porcelain fracture) •  Bulk fracture (core substructure fracture) •  Debonding of the prosthesis

Mechanical Failures •  Cracking

•  Chipping of veneering porcelain •  Cohesive chipping •  Adhesive delamination

•  Bulk fracture (core substructure fracture)

Transilumination !

Veneer porcelain chipping !

Delamination !

Core fracture!

Use Transillumination for Quality Control

Custom Fabrication•  All-ceramic restorations are custom-fabricated

increasing susceptibility to fabrication defects •  Variety of techniques

•  Sintering •  Heat-pressing •  Slip-casting •  CAD/CAM •  Combined with staining or veneering step

Each technique produces fabrication defects

[from Janine Tiu]

Diamond grinding is a major source of failure-inducing flaws in dense ceramics. (Rice 2002) Zirconia CAD/CAM machining creates damage that is not fully healed by sintering process. (Kim et al 2010)

Effects of Abrasive Grinding

Thermal shock

Characteristic Trace Lines After CAD/CAM Machining!

Lava!

Procera Zr!Everest (KaVo)!

DCS Zirkon!

Veneer Chipping in Zirconia-based RestorationsSystematic reviews confirm chipping of veneering ceramic is the most frequent complication More common than with metal-ceramic or other all-ceramic restorations (Al-Amleh et al 2010, Hientz et al 2010, Schley et al 2010, Raigrodski et al 2012)

Al-Amleh et al 2010 “Clinical trials in zirconia: A systematic review Summary:

•  17 clinical trials based on 3Y-TZP •  Posterior FPD 13 studies •  Single crowns 2 studies •  Implant abutments 2 studies

•  8 brands of zirconia •  Longest trial 5yrs (only 2 studies)

Chipping of veneering porcelain •  Two of 15 studies did not report chipping •  Was common for all brands •  Incidence ranged from 0 – 54% •  Not always noticed by patients – incidental finding •  Also found at non-load bearing areas

8 17

Difference between thermal conductivity between metal substructure and YZr substructure

Reasons for Zirconia Veneer ChippingHigh tensile residual stresses locked within the veneering porcelain (Swain 2009) Zirconia is a very poor thermal conductor: •  Gold: 315 W/m-K •  Alumina: 40 W/m-K •  Zirconia: 2 W/m-K

Substructure core design •  Cap-like core do not support veneering

porcelain •  Suggested “PFM-style” cut back method

[Tholey, Swain & Thiel 2011]

PFMs cool from the inside to the outside producing systematic compression bonding from the inside to the outside. YZr crowns cool from both the inside and the outside at a similar rate resulting in a compression layer in the outer veneer and YZr coping, and an inner zone of tension within the porcelain veneer.

W/(m.K), of a gold coping = 315

W/(m.K), of a zirconia coping = 2

Thermal conductivity, W/(m.K), of porcelain = 1.4

Zone of tension

Loading Zirconia Crowns to Failure fast cooled v slow cooled

Procera Zirconia IPS e.max ZirPress

Al-Amleh 2011

Fast Cooled Samples Common features: •  Midline fissure crack •  Cracking on mesial non-loaded side •  Average 902 N

Fracture after 2 days

Courtesy: Dr. L. Gruetter (University of Geneva)

Courtesy : Dr. L. Grütter (University of Geneva)

Occlusal contact point responsible for shearing off veneering ceramic

1. Clean (cotton pellet with alcohol), rinse & dry

2. Inject siloxane impression material (light body)

3. Cover the whole crown with silicon material

Procera Alumina AllCeram (veneering ceramic failure after 4 years)

Zirconia Abutment Fracture Case description:

1. The zirconia implant abutment was screwed in tightly

2. Contact points M, D, were adjusted in situ

3. On the first bite for occlusal adjustment the crown fractured

Zirconia abutment CARES (Straumann)

Zirconia Abutment Try-in Failure

The first bite to check the occlusion created a stress concentration at the distal margin (white arrow). The crack path is marked by the red arrows and result in the crown splitting in half.

origin Ø  Fabrication defect

Cercon 6-unit bridge failure after 24 hours

FPD Bulk (core) Fracture

Poor framework design •  Not enough palatal clearance •  Thin tip zirconia framework Both cause high stress concentrations Take home message:

Always try-in zirconia frameworks before veneering

All zirconia copings were rejected

No substructure support

Adequate substructure support allows for natural occlusal morphology

Procera Alumina All-Ceram (veneering ceramic failure after 4 years)

origin

Conclusion from the replica SEM analysis: The origin of the failure was located on the occlusal-palatal cusp (wear facette). The crack continued along the arrows downwards (interproximally) to the gingiva without reaching the margins. The veneering porcelain was unsufficiently supported by the alumina core

Guidelines for Restoring Chipped !All-ceramic Restorations

Grade 1: Fracture surface can be polished Grade 2: Fracture surface can be repaired with composite resin Grade 3: Severe fracture requires restoration replacement

1.  Fracture extends into a functional area and repair is not feasible

2. Re-contouring will result in a significant unacceptable alteration of the anatomic form from the original anatomy

3. Re-contouring will significantly increase the risk of pulp trauma by the generation of heat

4. Repair with resin composite will result in unacceptable aesthetic result

(Heintze & Rousson 2010, Anusavice 2012)

Success or Failure? •  Is a chipped all-ceramic restoration a failed

restoration? •  Restoration success is defined as the

demonstrated ability of a restoration to perform as expected

•  Acceptable surface quality •  Anatomic contour •  Function •  Aesthetics (where applicable)

•  When should we repair or replace the entire restoration?

•  Restoration failure may be defined as any condition that leads to replacement of a prosthesis

•  Why do all-ceramic fracture? •  How can we minimise this problem?

Origins of Fracture•  Fabrication flaws of various shapes

and sizes includes: •  Pores Micro-cracks •  Macro-cracks •  Machining grooves •  Air-abrasion surface defects •  Grinding adjustments surface

defects •  Location of the defect under tensile

stresses is important •  Thermal residual stresses •  Subcritical crack growth (SCCG)

•  In humid environment, cracks grow slowly but continuously Weakest link

Early v Late Fractures•  Immediate failure or within a few hours or

days of cementation is likely to originate from a major processing flaw

(Schmitter et al 2009, Lohbauer et al 2010)

•  Failure after a few years is likely to involve subcritical crack growth and/or cyclic fatigue SCCG and/or cyclic fatigue

Most important factor affecting fracture rates:

Position of restoration in the mouth

Ferrario et al 2004 Greatest forces Molars > premolars > incisors (1/3-1/4 of molars load)

Surface area of incisal edge of anteriors and occlusal table of posteriors?

AF

=σ

Occlusal contacts on natural teeth are point contacts

Causes of Ceramic Substructure Failure•  Fracture initiating in the connector area

•  Connector high stress area •  Chipping of the veneering material

•  Residual stresses at the core-veneer interface

•  Differences in thermal conduction between the core and veneer

•  Thick veneer layer •  Poor bonding between the core and veneer

ceramic •  Sliding occlusal contacts more damaging

than axial contacts

Summary•  Stronger ceramics are more opaque than

aesthetic ceramics •  Aesthetic restorations without much structural

need – use single layer (monolithic) ceramics •  High strength needed, less aesthetic ceramics

veneers with tooth coloured porcelain •  Any ceramic system suitable for veneers and

anterior crowns •  Only a few ceramics successful for restoring

molars •  Need to consider other clinical factors such as

adequate preparation depth and cementation

Summary•  No equivalent long-term data as for PFMs

•  ~75% at 15 years •  Many ceramics >90% after 5 years

•  Reasonable evidence available for anterior 3-unit FPDs in lithium disilicate, In-Ceram Alumina and Zirconia

•  Posterior 3-unit FPDs only zirconia indicated •  Chipping and fracture a problem •  Higher success when ceramics bonded to teeth

using resin cement rather than GIC •  Use a silica coating system or primers for acid resistant

ceramics such as zirconia

Ceramics in dentistry

Summary of Ceramics Recommendations Based on Peer Review Literature

Ceramics

Aluminous Core Slip Cast - In-Ceram

Hot Pressed - Empress Machined - Cerec , Procera

CeramicsSlip Cast

•  Build-up with core particles and fired •  High Strength •  Highly Abrasive •  Fair Marginal Fit

–  In-Ceram: crowns –  In-Ceram Spinell: crowns (more translucent) –  In-Ceram Zirconia: 3 unit FPD’s

In CeramThe image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.

The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again. The image cannot be displayed. Your

computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.

What is Slip Casting?

CeramicsHot-Pressed

•  Medium to High Strength •  Low to Medium Abrasive •  Medium Translucency •  Fair Marginal Fit

– Empress & Finesse (leucite) ✦  veneers, inlays, onlays, crowns

– Empress 2 (lithium disilicate) ✦ crowns, 3-unit FPD’s

What is Hot Pressed?Lost wax casting via pressed ceramic.

CeramicsMachined (CAD/CAM)

•  Medium to Very High Strength •  Low to Medium Abrasive •  Fair Marginal Fit •  Industrial CAD/CAM

– Procera: crowns, FPDs •  In-office CAD/CAM

– Cerec: inlays – Cerec 2 & 3: inlays, onlays, crowns

IPS e.max

KIc= 2.75 MPa√m KIc= 2.25 MPa√m

LiO2 - SiO2 (lithium disilicate)

S = 450 MPa S = 360 MPa T° = 850°C T° = 915-920°C


VITA In-Ceram® SPINELL

VITA In-Ceram® ALUMINA


VITA In-Ceram® ZIRCONIA


What is CAD/CAM ?

Computer Aided Design / Computer Aided Manufacture

CEREC® 3

inLab von Sirona

inEos von Sirona

CAD/CAM ?

CAD/CAM

CAD/CAM

CAD/CAM

© Praxisfall Dr. Gunpei Koike (Japan)

CAD/CAM


CAD/CAM

CAD/CAM


CAD/CAM

E4D HenrySchein

Cerec Sirona

Ivoclar Procera

NobelBiocare

CAD/CAM

All Ceramic Crowns

•  Indications –  High cosmetic demand –  Incisal edge reasonably intact –  Favourable occlusion

•  Advantages –  Cosmetics –  Good tissue response –  More conservative on labial

All Ceramic Crowns

•  Contraindications –  High strength required –  Insufficient tooth structure for support –  Unfavourable occlusion

•  Disadvantages –  Reduced strength –  Not conservative –  Brittle –  Single crowns only

Types of crowns

Full gold crown (FGC)

Porcelain fused to metal (PFM)

All ceramic

Affect of the Metal CopingThe image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.


Ceramic Crown Form 1The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.

Occlusal ConsiderationsThe image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.

Ceramic Crown Form

Tooth Preparation 1The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.


Tooth Preparation 2The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.




All-ceramics and Metal-ceramics

•  The need to simulate in dental porcelains the light behaviour and appearance of the natural tooth

•  Create the illusion of

nature within limited space constraints and light blocking effect of the metal substructure or ceramic substructure

Yamamoto 1985

Yamamoto 1985

Think Cosmetics

BleachingVeneers

Ceramic Crowns

Metal Ceramic Crowns

◆  Indications –  Heavily restored / endodontically treated tooth –  Cosmetics –  When ceramic crowns not possible

◆ Advantages –  Appearance compared with FGC –  Retentive

Metal Ceramic Crowns◆ Contraindications

–  Large pulp chamber –  Intact buccal wall –  More conservative restoration possible

◆ Disadvantages –  Amount tissue removal –  Occlusion difficult with glazed porcelain –  Appearance compared with ceramic

Gold Crowns

◆  Indications –  Heavily restored / endo treated tooth –  Correct occlusal plane –  Provide contours for RPD

◆ Advantages –  Strong –  Retentive

Gold Crowns

◆ Contraindications –  < Maximum retention required –  Cosmetics

◆ Disadvantages –  Amount tissue removal –  Metal display –  Vitality testing

Dimensions of the PreparationThe image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.

Light TransmissionThe image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.

Gold Crowns

◆  Indications –  Heavily restored / endo treated tooth –  Correct occlusal plane –  Provide contours for RPD

◆ Advantages –  Strong –  Retentive

Gold Crowns

◆ Contraindications –  < Maximum retention required –  Cosmetics

◆ Disadvantages –  Amount tissue removal –  Metal display –  Vitality testing

Preparation



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Date post:	15-Aug-2015
Category:	Health & Medicine
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Ceramics in fixed prosthodontics considerations for use in dental practice

Health & Medicine