Maxillary and mandibular overlay removable partial dentures for the restoration of worn teeth Mario R. Ganddini, DDS, a Majd Al-Mardini, DDS, b Gerald N. Graser, DDS, MS, c and Dov Almog, DMD d University of Rochester Eastman Dental Center, Rochester, NY This clinical report describes the fabrication of maxillary and mandibular cast overlay removable partial dentures for the restoration of severely worn teeth with accompanying loss of vertical dimension of occlusion. The frameworks supported porcelain veneers for esthetics and metal occlusal surfaces for strength and durability. (J Prosthet Dent 2004;91:210-4.) Prolonged tooth retention by the aging population increases the likelihood that clinicians may treat patients with advanced levels of wear. Tooth wear occurs as a natural physiological process; the average wear rates on occlusal contact areas were estimated to be 29 mm per year for molars and 15 mm per year for premolars. 1 Pathologic wear occurs when the normal rate of wear is accelerated by endogenous or exogenous factors. 2 Tooth wear caused by para-function is estimated to progress 3 times faster than physiological wear. 3 Tooth surface loss has been classified 4 into the following types: (1) erosion, loss of tooth surface by chemical processes not involving bacterial action, (2) attrition, tooth structure loss by wear of surface of tooth or restoration caused by tooth-to-tooth contact during mastication or para-function, and (3) abrasion, loss of tooth surface caused by abrasion with foreign substances other than tooth-to-tooth contact. Another classifica- tion divides tooth wear into 2 categories: mechanical wear caused by attrition or abrasion and chemical wear caused by erosion. 2 A differential diagnosis is not always possible because there may be a combination of these processes occurring. 5-8 Etiologic factors include bruxism, harmful oral habits, diet, gastroesophageal reflux disease, occu- pation, eating disorders, xerostomia, and congenital anomalies such as amelogenesis imperfecta and de- ntinogenesis imperfecta. 1-12 Clinical parameters have been suggested to aid in diagnosing the type of tooth wear and determining its cause. 2 Loss of vertical dimension of occlusion (VDO) caused by physiologic tooth wear is usually compensated by continuous tooth eruption and alveolar bone growth. 13 In situations where tooth wear exceeds compensatory mechanisms, loss of VDO occurs. The determination of the VDO can be achieved with several methods such as phonetics, interocclusal dis- tance, swallowing, and patient preferences. 8,14-16 In situations where loss of tooth structure has occurred and the VDO is still acceptable, treatment may include crown lengthening, orthodontic movement with limited in- trusion, surgical repositioning of a segment of teeth and supporting alveolar bone, and placement of crowns and fixed partial dentures. 8 In situations where loss of VDO has occurred, the cast overlay removable partial denture (CORPD) may be a treatment option. 17-24 This treatment option has been suggested to be efficient and cost effective, with the final outcome pleasing to the patient. 18 Potential disadvantages of CORPD prostheses include compromised esthetics when the dentures are removed, development of caries or periodontal disease as a result of poor oral hygiene, porcelain or resin veneer fracture or discoloration, and possible patient dissatisfaction with a removable pros- thesis. This clinical report describes the use of maxillary and mandibular CORPDs consisting of anterior porce- lain veneers, posterior cast overlays, and acrylic resin denture bases in the treatment of a patient with severe tooth wear caused by attrition and erosion. CLINICAL REPORT A 58-year-old white man was seen at the University of Rochester Eastman Dental Center’s prosthodontic clinic. The medical and dental histories were recorded, and a complete series of radiographs was made. History of high consumption of fruit juices and carbonated drinks and history of bruxing were reported. The clinical examination revealed severe tooth wear extending to the cervical level of the teeth in some areas. Clinical determination of the VDO was achieved with the following methods: phonetics, interocclusal distance, swallowing, patient preferences, and facial appearance. After careful assessment, it was determined that a 6-mm loss of VDO was caused by a combination of attrition and erosion (Figs. 1 and 2). The chief complaints in- cluded a desire to improve esthetics (‘‘poor appearance’’) a Graduate student, Prosthodontics. b Graduate student, Prosthodontics. c Professor, Prosthodontics. d Associate Professor, Prosthodontics. 210 THE JOURNAL OF PROSTHETIC DENTISTRY VOLUME 91 NUMBER 3
Transcript
21
Maxillary andmandibular overlay removable partial dentures for the restorationof worn teeth
Mario R. Ganddini, DDS,a Majd Al-Mardini, DDS,b Gerald N. Graser, DDS, MS,c
and Dov Almog, DMDd
University of Rochester Eastman Dental Center, Rochester, NY
This clinical report describes the fabrication of maxillary and mandibular cast overlay removable partialdentures for the restoration of severely worn teeth with accompanying loss of vertical dimension ofocclusion. The frameworks supported porcelain veneers for esthetics and metal occlusal surfaces forstrength and durability. (J Prosthet Dent 2004;91:210-4.)
Prolonged tooth retention by the aging populationincreases the likelihood that clinicians may treat patientswith advanced levels of wear. Tooth wear occurs asa natural physiological process; the average wear rates onocclusal contact areas were estimated to be 29 mm peryear for molars and 15 mm per year for premolars.1
Pathologic wear occurs when the normal rate of wear isaccelerated by endogenous or exogenous factors.2
Tooth wear caused by para-function is estimated toprogress 3 times faster than physiological wear.3
Tooth surface loss has been classified4 into thefollowing types: (1) erosion, loss of tooth surface bychemical processes not involving bacterial action, (2)attrition, tooth structure loss by wear of surface of toothor restoration caused by tooth-to-tooth contact duringmastication or para-function, and (3) abrasion, loss oftooth surface caused by abrasionwith foreign substancesother than tooth-to-tooth contact. Another classifica-tion divides tooth wear into 2 categories: mechanicalwear caused by attrition or abrasion and chemical wearcaused by erosion.2
A differential diagnosis is not always possible becausethere may be a combination of these processesoccurring.5-8 Etiologic factors include bruxism, harmfuloral habits, diet, gastroesophageal reflux disease, occu-pation, eating disorders, xerostomia, and congenitalanomalies such as amelogenesis imperfecta and de-ntinogenesis imperfecta.1-12 Clinical parameters havebeen suggested to aid in diagnosing the type of toothwear and determining its cause.2
Loss of vertical dimension of occlusion (VDO)caused by physiologic tooth wear is usually compensatedby continuous tooth eruption and alveolar bonegrowth.13 In situations where tooth wear exceedscompensatory mechanisms, loss of VDO occurs.
aGraduate student, Prosthodontics.bGraduate student, Prosthodontics.cProfessor, Prosthodontics.dAssociate Professor, Prosthodontics.
0 THE JOURNAL OF PROSTHETIC DENTISTRY
The determination of the VDO can be achieved withseveral methods such as phonetics, interocclusal dis-tance, swallowing, and patient preferences.8,14-16 Insituations where loss of tooth structure has occurred andtheVDO is still acceptable, treatmentmay include crownlengthening, orthodontic movement with limited in-trusion, surgical repositioning of a segment of teeth andsupporting alveolar bone, and placement of crowns andfixed partial dentures.8 In situations where loss of VDOhas occurred, the cast overlay removable partial denture(CORPD) may be a treatment option.17-24
This treatment option has been suggested to beefficient and cost effective, with the final outcomepleasing to the patient.18 Potential disadvantages ofCORPD prostheses include compromised estheticswhen the dentures are removed, development of cariesor periodontal disease as a result of poor oral hygiene,porcelain or resin veneer fracture or discoloration, andpossible patient dissatisfaction with a removable pros-thesis. This clinical report describes the use of maxillaryand mandibular CORPDs consisting of anterior porce-lain veneers, posterior cast overlays, and acrylic resindenture bases in the treatment of a patient with severetooth wear caused by attrition and erosion.
CLINICAL REPORT
A58-year-old whitemanwas seen at theUniversity ofRochester Eastman Dental Center’s prosthodonticclinic. The medical and dental histories were recorded,and a complete series of radiographs was made. Historyof high consumption of fruit juices and carbonateddrinks and history of bruxing were reported. The clinicalexamination revealed severe tooth wear extending to thecervical level of the teeth in some areas. Clinicaldetermination of the VDO was achieved with thefollowing methods: phonetics, interocclusal distance,swallowing, patient preferences, and facial appearance.After careful assessment, it was determined that a 6-mmloss of VDO was caused by a combination of attritionand erosion (Figs. 1 and 2). The chief complaints in-cluded a desire to improve esthetics (‘‘poor appearance’’)
VOLUME 91 NUMBER 3
THE JOURNAL OF PROSTHETIC DENTISTRYGANDDINI ET AL
and function (‘‘would like to chew better’’), andeliminate tooth sensitivity (‘‘my teeth are sensitive’’).
Impressions were made of both arches using stocktrays and irreversible hydrocolloid (Jeltrate Plus;Dentsply Caulk, Inc, Milford, Del) and poured in stone(Quickstone; Whip Mix, Louisville, Ky). The diagnosticcasts were articulated in a semiadjustable articulator(Hanau H2; Hanau Teledyne, Buffalo, NY), usinga centric relation record and a face-bow transfer.
During the following visit, treatment options werediscussed with the patient, including crown lengthen-ing, endodontic therapy, and fixed restorations. Afterconsidering the life expectancy of fixed partial de-ntures,25 invasiveness, amount of time, and financialaspects, the patient elected to have CORPDs withanterior porcelain veneers, posterior cast overlays, andacrylic bases. Porcelain veneers were used in the anteriorarea because they are more durable and color stable thancomposite.26,27 Moreover, composite veneers are moreexpensive than porcelain, while resin laminates are theleast expensive. Metal coverage was used on the occlusalsurface of the posterior teeth to maintain the newlyestablished VDO. Once sufficient occlusal support wasestablished, resin teeth were used for the edentulousareas as a matter of laboratory convenience and ease offabrication.
After extractions of nonrestorable teeth because ofextensive decay or wear, and restoration of carious teeth,the patient was re-evaluated and referred to a dental hy-gienist for oral hygiene instructions and a maintenanceprogram (once every 6 months). After approximately 6weeks of healing, prosthetic treatment commenced. Thenew diagnostic casts were articulated with a new centricrelation record and a face-bow transfer.
Diagnostic tooth arrangements were made to estab-lish the new VDO and the plane of occlusion, on thebasis of anatomic landmarks and averaged values.15 Thediagnostic arrangements were duplicated using irrevers-ible hydrocolloid (Jeltrate Plus; Dentsply Caulk, Inc)and then poured in dental stone (Quickstone,WhipMixCorp). Thermal forming material, 1.0-mm thick,(Splint; Henry Shein, Melvile, NY) was then appliedover the new casts. The occlusal aspects of the thermoforming material were lubricated and then filled withautopolymerizing acrylic resin (Jet Tooth Shade Acrylic;Lang Dental, Wheeling, Ill). After polymerization, theocclusal aspects of the thermal formingmaterial were cutaway to expose the underlying acrylic resin teeth, andthen positioned back on a duplicate of the diagnosticcasts. These served as a transitional VDO device, whichwas then transferred to the patient. These devices fittightly over the teeth and soft tissues, enablingevaluation and adjustment for phonetics, esthetics, andocclusion.14-16
On the basis of the newly established VDO, thetransitional maxillary and mandibular VDO devices
MARCH 2004
were given to the patient. The transitional VDO deviceswere worn for approximately 6 weeks, during whichocclusal adjustments were made on a weekly basis, andocclusion was modified on the basis of phonetic andesthetic principles, as well as patient comfort and ease offunction.
The diagnostic casts were surveyed to determine themost suitable path of insertion of the definitiveprostheses. Each cast was placed in a horizontal positionand slowly lowered posteriorly on the surveyor untilundercuts at the distobuccal of the first and secondmolarregions were of sufficient depth (0.25 mm). As theseteeth were not present in all quadrants, undercutconsiderations were applied to the most posterior teeth.A slight undercut in the anterior region allowed for theuse of a rotational path of insertion.
The information from the diagnostic cast was nowreplicated intraorally. Unsupported enamel was recon-toured and polished. In some instances, facial reductionof enamel surface in the esthetic zone was required toaccommodate the porcelain veneers which would befused to the CORPD framework. Guide planes wereplaced on proximal tooth surfaces. Because of the wearon many of the remaining teeth, a natural undercut foradequate retention could not be located. Therefore,existingenamel surfacesweremodified to create anunder-cut of 0.25 mm, for the use of cast half-round circum-ferential clasps. Dentin exposure occurred, but this wasmanaged with a thorough maintenance program. Restseat preparations were not needed because the entireocclusal surface of all the teeth served as rests under thecast framework.
Definitive impressions were made using a polyetherimpression material (Permadyne Penta H and Perma-dyne Garant 2:1, 3M ESPE, St Paul, Minn) and customtrays (Triad VLC Materials; Denstsply International,
Fig. 1. Intraoral anterior view of patient presenting severelyworn maxillary and mandibular dentition and loss of VDO.
211
THE JOURNAL OF PROSTHETIC DENTISTRY GANDDINI ET AL
Fig. 2. Intraoral occlusal view of maxillary (A) and mandibular (B) dentition.
Fig. 3. Intraoral occlusal view of maxillary (A) and mandibular (B) CORPD frame try-in. Note alloy copings in esthetic zone.
York, Pa). Casts were made and mounted in centricrelation. The incisal guiding pin was then adjusted fora 6-mm increase in VDO.Once the path of insertion wasestablished for both casts, the undesirable undercutswere blocked out with wax and the casts were duplicatedand poured in a refractory investment (Hi-Temp; WhipMix Corp). The refractory casts were also mounted inthe articulator using a cross-cast mounting procedurebetween the definitive casts and the refractory casts.
The frameworks were waxed, using a thin layer of wax(Flexseal Patterns; Dentsply Trubyte/Austenal, York,Pa) over the teeth to be included in the prosthesis,except for the surfaces to be clasped. The posteriorocclusal surfaces were waxed to occlusion and patternsfor clasps andmesh to retain the acrylic resin were added.A butt joint was placed on the lingual surfaces of the
212
anterior portion of the frameworks to support porcelainveneers. The wax patterns were cast in a chrome-cobaltalloy (Vitallium; Dentsply Austenal). The cast frame-works were then finished.
The frameworks were evaluated intraorally for fit,occlusion, retention, and stability (Fig 3). A newmaxillomandibular relationship record was made withthe frameworks in position, and the definitive casts weremounted in the articulator. The frameworks werereturned to the laboratory for the application of por-celain veneers in the esthetic zone, and artificial acrylicresin teeth (Dentsply Trubyte, York , Pa) and heat-poly-merizing acrylic resin (Lucitone 199; Dentsply Trubyte)in the edentulous posterior regions. A bilaterally bal-anced occlusal scheme was developed using a 20-degreeplane. Although the esthetic zone in the CORPD can be
VOLUME 91 NUMBER 3
THE JOURNAL OF PROSTHETIC DENTISTRYGANDDINI ET AL
fabricated either with composite28 or porcelain veneers,in this patient, microcrystal porcelain veneers (Avante;Pentron Laboratory Technology, Wallingford, Conn)were applied directly to the framework.29 Chromecobalt bonding agent (CKB; Bredent, Miami, Fla)enabled bonding of the veneers directly onto thecasting. CKB is a ceramic material used to form a layerbetween metals and ceramic and is purported tocompensate for different expansion coefficients betweenmetal and ceramic and blocks escaping metal oxides.After processing, the casts were remounted, and theocclusion was adjusted to remove any processing errors.
At the next visit, the CORPDs were inserted (Figs. 4and 5). After postoperative instructions on how toproperly insert the prostheses, the patient was provided
Fig. 4. Intraoral anterior view of restored maxillary andmandibular dentition.
Fig. 5. Facial view of restored maxillary and mandibulardentition.
MARCH 2004
with instructions on adequate oral hygiene, and cariesand erosion prevention. These included the applicationof sodium fluoride neutral mineral (PreviDent 5000Plus; Colgate Oral Pharmaceuticals, Canton, Mass) inthe intaglio of the CORPDs, and dietary counseling.The patient was also instructed to remove the CORPDsat night and wear a maxillary soft night guard made of3.0-mm thermal forming material (Mouthguard; GreatLakes Orthodontics, Ltd, Tonawanda, NY). After 2postinsertion visits that includedminor adjustments, thepatient was placed on a 6-month recall.
SUMMARY
This clinical report demonstrated that the use ofCORPDs can be a viable, relatively inexpensive, andnoninvasive choice of treatment for a patient witha severely worn dentition who expresses concerns overtreatment longevity, invasiveness, cost, and long-termmaintenance.
The authors thank Mike Hagan from Hagan Prosthetic Services,
Inc, Rochester, NY, who provided the laboratory work presented by
the authors in this clinical report.
REFERENCES
1. Lambrechts P, Braem M, Vuylsteke-Wauters M, Vanherle G. Quantitative
in vivo wear of human enamel. J Dent Res 1989;68:1752-4.
2. Verrett RG. Analyzing the etiology of an extremely worn dentition.
J Prosthodont 2001;10:224-33.
3. Xhonga FA. Bruxism and its effect on the teeth. J Oral Rehabil 1997;4:
65-76.
4. Glossary of Prosthodontic Terms. J Prosthet Dent 1999;81:39-110.
5. Smith BG, Bartlett DW, Robb ND. The prevalence, etiology and
management of tooth wear in the United Kingdom. J Prosthet Dent
1997;78:367-72.
6. Smith BG, Knight JK. A comparison of patterns of tooth wear with
aetiological factors. Br Dent J 1984;157:16-9.
7. Lewis KJ, Smith BG. The relationship of erosion and attrition in extensive
tooth tissue loss. Case reports. Br Dent J 1973;135:400-4.
8. Turner KA, Missirlian DM. Restoration of the extremely worn dentition.
J Prosthet Dent 1984;52:467-74.
9. Gregory-Head BL, Curtis DA, Kim L, Cello J. Evaluation of dental erosion
in patients with gastroesophageal reflux disease. J Prosthet Dent 2000;
83:675-80.
10. Smith BG, Knight JK. A comparison of patterns of tooth wear with
aetiological factors. Br Dent J 1984;157:16-9.
11. Johansson A, Omar R. Identification and management of tooth wear. Int J
Prosthodont 1994;7:506-16.
12. Dahl BL, Carlsson GE, Ekfeldt A. Occlusal wear of teeth and restorative
materials. A review of classification, etiology, mechanism of wear, and
some aspects of restorative procedures. Acta Odontol Scand 1993;
51:299-311.
13. Murphy T. Compensatory mechanisms in facial height adjustment to
functional tooth attrition. Aust Dent J 1959;4:312-23.
14. Tjan AHL, Miller GD, The JG. Some esthetic factors in a smile. J Prosthet
Dent 1984;51:24-8.
15. Halperin AR, Graser GN, Rogoff GS, Plekavich EJ. Mastering the art of
