Restoring the Worn Dentition Robert L . lhseri. O.D., D.D.S., F.A.G.D.* Dmid F . Oitellet, 0.D .S.
Strong dental materials and dental porcelains are providing dentists with restorative opportunities that are more conservative because they require less destruction of healthy tooth structure and yield a more esthetic result. In cases of severe wear due to attrition, abrasion, and erosion, this process can be stopped, restoring the esthetics and function by using proper techniques and materials. The case report described in this article demonstrates the conservative restoration of severe wear due to attrition and erosion. Teeth were lengthened, wear was restored, and further wear was ceased by using a combination of bonded porcelain, a heat, light, and self-cureresin system, and a new glass-ionomerrestorative material. The result was a strong, durable restoration (that required no anesthesia) with high esthetics.
R
estoring and preventing tooth wear caused by attrition, abrasion, and erosion has long been a challenge to dental professionals. After the loss of protective enamel, the wear process speeds on the exposed dentin. Teeth may become sensitive, the vertical dimension is altered, and the esthetics are afTected. The primary goal for treatment is to restore the lost tooth structure to provide both function and esthetics. Traditionally, treatment choices have been limited to multiple metal or metal-ceramic crowns. The degree, location, and extent of wear each affect the treatment choice. Various methods have been proposed for the reconstructive treatment of tooth wear. Multiple metal/ metal-ceramic crowns or crowns with denture combination might be the treatment choice.'.2However,metal crowns require further destruction of remaininghealthy tooth structure and these conventional restorations can be 'bonded" to tooth structure. Dental porcelains have recently presented an interesting alternative in restorative dentistry. These porcelains are highly durable, resemble the physical properties of human enamel, and are highly esthetic. They have been used for the veneering of etched enamel surfaces; however, their use on dentin surfaces is limited.
With the development of new bonding restorative materials and a bonded porcelain technique, porcelain can be chemically and mechanically fused to tooth structure. The case report presented below describes a technique that uses bonded porcelain veneers, and Vshaped porcelain crowns to halt severe tooth wear and restore normal occlusal relation.
Case Report The patient was a 34-year-old male with a Class I occlusion. Considerable wear was observed intraorally, especially on the anterior dentition (Figs. 1.2,and 3).Milder wear was found on bicuspids and first molar occlusal
.President. Den-Mat Corporation. Santa Maria. California: Clinlcal Lecturer. Henxy M. Goldman School of Graduate Dentistry at Boston University, Boston. Massachusetts:Clinlcal Instructor.UniversityofSouthernCalifornia. Los Angeles. California: Cllnlcal Associate Professor of Operative Dentistry. New York University. New York. New York. t Private Practlce. Santa Marla, California: Dental Materials Research Consultant. Den-Mat Corporation. Santa Marla. California. AddressreprintrequeststoDr. Robertlbsen. 730East Chapelstreet.Sank Maria, CA 93454. 0 1992 Decker Periodicals Inc.
Figure 1. Patient in centric.
96
Restoring the Worn Dentition
pisUre 2. Patient closed in centric, incisal view.
Figure 4. Severe wear of bicuspids before in buccal cuspid of first molar demonstrating wear.
Figure 3. 'Qpical wear of anteriors. incisal view.
pyeare
surfaces (Fig. 4). The lingual view demonstrates the large areas of exposed dentin (Fig. 5). The first step in restoring the original appearance and function, and to stop further wear, is accomplished by bonding porcelain laminates and V-shaped crowns on the anterior teeth. The bonding agents used were Tenure (Den-Mat, Santa Maria, CA) on the dentin and enamel, CerinatePrime (Den-Mat)on the porcelain, and Ultra-Bond (Den-Mat) between the porcelain and tooth structure. Figures 6 and 7 are the mandibular and maxillary laboratory working models. The blue die relief materials show where the porcelain will be placed. No labial enamel was removed on the maxillary teeth. Figure 8 shows a laminate for a mandibular central incisor demonstrating lengthening of teeth on the model. Figure 9 shows maxillary porcelain being tested for length. At the beginning of this case, it was planned to restore the anterior dentition without opening of the patient's vertical dimension, even with the 3-4 mm severe wear. Upon installing the maxillary and mandibular porcelain restorations. however, it was suddenly apparent that centric could be obtained if the bite
''
Large
Of
exposed dentin On maxillary.
Figure 6. Mandibular model: blue die relief on teeth restored with porcelain.
97
JOUR!AL OF ESTHETIC DEI\TISTRI’ \’OLUME 4.NUMBER 3 May/June 1992
Figure 10. Mandibular anteriors with Geristore applied on occlusal of bicuspids.
Figure 7. Maxillary model: blue die relief on porcelain.
was opened 2 mm at the first molar and bicuspid area. The second molars were contacting in centric at the beginning of the procedure and were still contacting in centric after the porcelain was in place on the six anterior mandibular and maxillary teeth. This 2-mm space is perhaps the amount of tooth structure worn away in the past 10-15 years. The next problem to be resolved was how to keep teeth from contacting in the first molar bicuspid areas. Traditionally, in order to maintain the vertical dimension, a bite plate would be made. However, since Tenure and Geristore (Den-Mat),a hydrophilic self-adhering restorative, can bond to worn surfaces on elderly patients, it was decided to restore the mandibular arch with Geristore using the core build-up technique for adding material to mandibular bicuspids and &st molar (Fig. 10). The occlusal surfaces of the maxillary bicuspids were treated first with Tenure. Next,Truevitality (DenMat), a self-cured, heat-cured, light-cured resin system, was applied as if it were a wax mush bit. A separating media was placed on the mandibular (glycerin), and the patient was instructed to close in centric. While the patient was closed, the Truevitality was lightcured. After the resin was set, the patient was instructed to open and the correct anatomic contour was installed, taking care not to touch the areas of centric contact in the fossa areas. When the contouring was complete, the patient now had a resin system that could easily be removed to maintain the vertical: however, because of the cuspid-guidance and anterior disclusion (porcelain-on-porcelain),no wear will take place on the resin of the posterior teeth because of the protection of the anterior segment. Figure 11 demonstrates the occlusal view of the teeth restored with porcelain and TrueVitality. Figures 12 and 13show the lateral occlusion on both sides, and Figure 14 shows the anterior disclusion. Figures 15 and 16 demonstrate that the
8* Labiallengthening ofmandibular tee*with ‘emate Porcelain Laminate on model.
Pyeure 9. Cerinate porcelain V-shaped crown lengthening maxillary teeth.
98
Restoring the Worn Dentition
Figure 11. Occlusal \dew of maxillary teeth with porcelain installed on anteriors and Truevitality resin on bicuspids.
Figure 14. Patient with anterior disclusion.
Figure 12. Patient in right working.
Figure 15. Patient restored vertical dimension 2.5 mm in centric.
pisnre 13. Patient in left working.
Figure 16. Close-up of restoration, in centric.
99
'The porcelain bonding technique used in this study relies on two important factors. Firstly. the porcelain must have enough strength to withstand the occlusal forces in addition to having high esthetic results. Secondly. since there is a large amount of exposed dentin, the bonding materials must bond strongly to dentin and have negligible film thickness. In addition, the luting agent must offer high strength to prevent fracturing of the porcelain. The porcelain used in this case was Cerinate porcelain (Den-Mat).This patented porcelain exhibits higher strengths, greater translucency, and demonstrates moderate thermal expansion (12x10 C Recently, Wassenaar reported the flexural strength of several porcelains.6The flexural strength (in MPa) of Cerinate is 124, Vitadur N (Vita - a n opaque aluminous porcelain) is 112, and Mirage Body (Chameleon Dental Products) is 60.6 Ultra-Bond is a n Amencan Dental Association certified Type I1 (Specification 27) composite restorative that lutes and bonds any type of porcelain restoration. The uniqueness of Ultra-Bond is that it contains a patented curing system-a photo-initiated dual cure that is light cured and chemical cured. Compared with typical dual-cure systems that start curing as soon as two parts are mixed, and cure faster upon the initiation of light, Ultra-Bond will not begin to cure when the two parts are mixed. It begins when the material is exposed to a strong light and stops curing only when all material has been polymerized. The clinical significance of this curing system is that it gives the dentist a longer working time (approximately 30 minutes) and the opportunity to do multiple laminate placement.' A recent study showed that a porcelain restoration using Cerinate porcelain and Ultra-Bond achieved 100 percent survival after thermal stressing in lab testing.8 Long-term clinical studies support the reliability of Cerinate and Ultra-bond restorations."1* The bonding materials used in this study were Tenure and Ultra-Bond. Many studies report that Tenure has the highest bond strength, l 5 . I 8 good microleakage resistance, and excellent b i ~ c o m p a t i b i l i t y .Ten~~.~~ ure is a n all liquid chemical-cure system and has a very thin film thickness.25 Unlike some resin-based lightcuring systems (e.g., Scotchbond 2[3Ml, or Prisma 2 and Prisma 3 [L.D. Caulk/Dentsply]), which could not be used under porcelain bonded restorations because they are light cured, the porcelain is quite thick in some areas thereby reducing the light energy available to polymerize the Ultra-bond, and have thick film thicknesses. Ultra-Bond also has better matched coefficient of thermal expansion than typical low viscosity luting agents. Tenure is an ideal bonding agent for use with bonded porcelain restorations because it is a self-cured, all liquid system. The wear on posterior occlusal surfaces was restored by using Geristore and TrueVitality. Geristore was applied directly to the worn dentition instead of a prepared cavity. Geristore is a cross product of glass-
patient occludes in centric. Comparing the original photograph nith the finished result. the porcelain restoration increased the length of the teeth and improved the overall esthetics. The patient has been observed monthly for 12 months, has had no failures, and has noTMJ problems. At a later time, the posterior segment will be restored uith a combination ofcast gold and bonded porcelain on the occlusal surface.
DISCUSSION The primary causes of tooth loss are caries, periodontal disease, and wear. Increasing dental awareness among the population has significantly reduced caries and periodontal problems, resulting in a greater proportion of the population retaining their teeth well into adult life. This increasing aged population has borne increasing clinical cases of tooth wear caused by attrition, abrasion. and erosion. Attrition is the wearing away of the tooth surface by tooth-to-tooth contact; abrasion is tooth surface loss caused by the introduction of abrasive substances, materials, or habits into the mouth. Erosion is the loss of tooth substance due to acid. The severe wear in this case was caused by a combination of attrition and abrasion. it was interesting to learn that the patient's cousin, who is about the same age, had the same type of worn dentition. The treatment. however, was complete teeth extraction and complete denture restoration. The anterior worn dentition was restored with a porcelain bonding technique that required very minor tooth reduction and no shoulder preparations. Porcelain laminates, V-shaped porcelain crowns, and porcelain pieces were fused to the tooth structure with Tenure bonding agent and Ultra-Bond restorative. Cuspid-guided occlusion was also established. Ibsen first reported a technique utilizing bonded porcelain restorations to achieve cuspid-guided o c c l ~ s i o nIt. ~is well accepted that cuspid-guided occlusion can protect teeth from wearing.4 Cuspid-guided occlusion with bonded porcelain functions by bonding porcelain pieces to the lingual maxillary cuspids, and porcelain laminates were bonded to the labial mandibular cuspids. At this time. when the patient closes in centric, the only contacts are on cuspids. Then selective grinding is used to achieve a uniform contact on all dentition in centric. The bonded porcelain pieces to the lingual maxillary cuspids provides a porcelain slide that contacts the porcelain laminates bonded to the labial incisal of the mandibular cuspids. This slide path technique provides a constant porcelain-to-porcelain contact. When the teeth move to lateral, the posterior teeth separate, which means that further wear will no longer occur as the teeth separate and they slide out of centric due to the eccentric contact of porcelain on maxillary and mandibular cuspids. 100
Restoring the Worn Dentition
ionomer and composite resin. It adheres to all intraoral surfaces without a separate bonding agent.26It also releases fluoride, which could be helpful to prevent caries, and it is visually translucent.
9. Jordan R. Suzuki M, Senda A. Clinical evaluation of porcelain laminate veneers: a four year recall report. J Esthet Dent 1989: 1:12&-132. 10. Strassler HF. Nathanson D. Clinical evaluation of etched porcelainveneersoveraperiodof 18to 42 months. J Esthet Dent 1989: 1:21-28. 11. Christensen GR, Christensen RP. Porcelain veneers-two years of clinical sendce. J Dent Res 1990; 69:303. Abstract 1553. 12. Griswold W. Gunderson R, Strassler H. Thompson VP. One to two year clinical evaluation of porcelain veneers. J Dent Res 1991: 70:386. Abstract 960. 13. Ibsen RL, Strassler H. A n innovative method for fixed anterior tooth replacement utilizing porcelain veneers. Quintessence Int 1986: 17:455-459. 14. Jenkins C. Aboush Y. Clinical durability of porcelain laminates over 8 years. J Dent Res 1981: 60: 1081. 15. Barkmeier WW, Cooley RL. Resin adhesive systems: in vitro evaluation of dentin bond strength and marginal microleakage. J Esthet Dent 1989: 1:67-72. 16. Wieczkowski G, Yu X Y , Joynt RB. Davis EL. Dentin bonding strength in a three dimensional cavity preparation. J Dent Res 1990: 69: 116. Abstract 62. 17. Stewart BL. Harcourt J K , Tyas MJ. Comparison of dentine bond strength to dentine in cavities restored before and after extraction. J Dent Res 1990; 69:945. Abstract 99. 18. Golub-Evans J . Battle of the bonds: dentists compare dentin bonding agents. Dentist 1990: July/August: 1-3. 19. White SN. Sorensen JA, Kang SK, Caputo AA. Microleakage of new luting agents. J Dent Res 1990: 69:173. Abstract 514. 20. Lynch E. Samarawickrama D. Auger D. Artificial lesion formation around restorations in tooth roots. J Dent Res 1989: 68:573. Abstract 119. 21. Yu X Y , Wieczkowsld G. Davis EL, Joynt RB. The influence of finishing technique on microleakage. J Esthet Dent 1990: 2~142-145. 22. Yu X Y , Davis EL, Joynt RB.Wieczkowski G Jr. Evaluation of microleakage in Tenure-based restorations. J Esthet Dent 1990: 2:145-147. 23. Li Y, Noblitt TW. Dunipace AJ,Stookey GK. Evaluation of mutagenicity ofrestorative dental materialsusingtheAmes salmonella/microsome test. J Dent Res 1990: 69: 1 1881192. 24. Waknine S. Gable P, Schulman A. Physicomechanical, adhesion and cytotoxicity characterization of eleven commercial dentin adhesives. J Dent Res 1989; 68:375. Abstract 1546. 25. Ibsen RL. Glace WR.Bond strength of a low film thickness oxalate resin cement. J Dent Res (in press). Presented a t the San Francisco AADR 1989. 26. Pacropis DR, Ibsen RL. Studies on a fluoride releasing adhesive to various substrates. J Dent Res 1991: 70:479. Abstract 1701.
CONCLUSIONS Using a combination of bonded porcelain and specialized resin bonded systems, a practical, simplified method of restoring wear, preventing wear. strengthening tooth structure, and improving esthetics has been presented. This method could also be used to eliminate the need for mouthguards as the posterior teeth will not be able to contact any more except in centric. The average practitioner who uses proper materials and understands occlusion can offer this treatment to their patients who have varying degrees of wear.* High strength porcelains are traditionally opaque and made from aluminum oxide. Cerinate Porcelain was selected because, in the study by Wassenaar, it has flexural strengths of opaque porcelains but is translucent. This eliminates the necessity for excessive reduction of tooth structure required by aluminous opaque porcelains. *A video tape demonstrattng this technique is available by contacting the author.
REFERENCES 1. Shillingburg HT, Hobo S , Whitsett LD. Fundamentals of flxedprosthodontics. 2ndEd. Chicago: Quintessence, 1981. 2. Rawlinson A. Winstanley RB. The management of severe dental erosion using posterior occlusal porcelain veneers and an anterior overdenture. Restor Dent 1989: 4:1O-16. 3. Ibsen RL, Yu XY. Establishing cuspid-guided occlusion with bonded porcelain. J Esthet Dent 1989; 1:8O-85. 4. Goldstein GR. The relationship of canine-protected occlusion to a periodontal index. J Prosthet Dent 1979: 41: 277-283. 5. Chadwick TC. Ibsen RL. Properties of a new porcelain for veneers, inlays and crowns. J Dent Res 1989; 68:956. Abstract 712. 6. Wassenaar P. The new porcelains--Are they any better? Aust Dent J 1990; 4(Suppl):19-25. 7. Putter H. Ibsen RL. Simultaneous placement of multiple porcelain veneers. J Esthet Dent 1990; 2:67-69. 8. Sorenson J, Kang SK, Avera SP. Porcelain composite interface microleakage withvarious porcelain surface treatments. J Dent Res 1990; 69:359. Abstract 2008.
101
Strong dental materials and dental porcelains are providing dentists with restorative opportunities that are more conservative because they require less destruction of healthy tooth structure and yield a more esthetic result. In cases of severe wear due to attrition, abrasion, and erosion, this process can be stopped, restoring the esthetics and function by using proper techniques and materials. The case report described in this article demonstrates the conservative restoration of severe wear due to attrition and erosion. Teeth were lengthened, wear was restored, and further wear was ceased by using a combination of bonded porcelain, a heat, light, and self-cureresin system, and a new glass-ionomerrestorative material. The result was a strong, durable restoration (that required no anesthesia) with high esthetics.
R
estoring and preventing tooth wear caused by attrition, abrasion, and erosion has long been a challenge to dental professionals. After the loss of protective enamel, the wear process speeds on the exposed dentin. Teeth may become sensitive, the vertical dimension is altered, and the esthetics are afTected. The primary goal for treatment is to restore the lost tooth structure to provide both function and esthetics. Traditionally, treatment choices have been limited to multiple metal or metal-ceramic crowns. The degree, location, and extent of wear each affect the treatment choice. Various methods have been proposed for the reconstructive treatment of tooth wear. Multiple metal/ metal-ceramic crowns or crowns with denture combination might be the treatment choice.'.2However,metal crowns require further destruction of remaininghealthy tooth structure and these conventional restorations can be 'bonded" to tooth structure. Dental porcelains have recently presented an interesting alternative in restorative dentistry. These porcelains are highly durable, resemble the physical properties of human enamel, and are highly esthetic. They have been used for the veneering of etched enamel surfaces; however, their use on dentin surfaces is limited.
With the development of new bonding restorative materials and a bonded porcelain technique, porcelain can be chemically and mechanically fused to tooth structure. The case report presented below describes a technique that uses bonded porcelain veneers, and Vshaped porcelain crowns to halt severe tooth wear and restore normal occlusal relation.
Case Report The patient was a 34-year-old male with a Class I occlusion. Considerable wear was observed intraorally, especially on the anterior dentition (Figs. 1.2,and 3).Milder wear was found on bicuspids and first molar occlusal
.President. Den-Mat Corporation. Santa Maria. California: Clinlcal Lecturer. Henxy M. Goldman School of Graduate Dentistry at Boston University, Boston. Massachusetts:Clinlcal Instructor.UniversityofSouthernCalifornia. Los Angeles. California: Cllnlcal Associate Professor of Operative Dentistry. New York University. New York. New York. t Private Practlce. Santa Marla, California: Dental Materials Research Consultant. Den-Mat Corporation. Santa Marla. California. AddressreprintrequeststoDr. Robertlbsen. 730East Chapelstreet.Sank Maria, CA 93454. 0 1992 Decker Periodicals Inc.
Figure 1. Patient in centric.
96
Restoring the Worn Dentition
pisUre 2. Patient closed in centric, incisal view.
Figure 4. Severe wear of bicuspids before in buccal cuspid of first molar demonstrating wear.
Figure 3. 'Qpical wear of anteriors. incisal view.
pyeare
surfaces (Fig. 4). The lingual view demonstrates the large areas of exposed dentin (Fig. 5). The first step in restoring the original appearance and function, and to stop further wear, is accomplished by bonding porcelain laminates and V-shaped crowns on the anterior teeth. The bonding agents used were Tenure (Den-Mat, Santa Maria, CA) on the dentin and enamel, CerinatePrime (Den-Mat)on the porcelain, and Ultra-Bond (Den-Mat) between the porcelain and tooth structure. Figures 6 and 7 are the mandibular and maxillary laboratory working models. The blue die relief materials show where the porcelain will be placed. No labial enamel was removed on the maxillary teeth. Figure 8 shows a laminate for a mandibular central incisor demonstrating lengthening of teeth on the model. Figure 9 shows maxillary porcelain being tested for length. At the beginning of this case, it was planned to restore the anterior dentition without opening of the patient's vertical dimension, even with the 3-4 mm severe wear. Upon installing the maxillary and mandibular porcelain restorations. however, it was suddenly apparent that centric could be obtained if the bite
''
Large
Of
exposed dentin On maxillary.
Figure 6. Mandibular model: blue die relief on teeth restored with porcelain.
97
JOUR!AL OF ESTHETIC DEI\TISTRI’ \’OLUME 4.NUMBER 3 May/June 1992
Figure 10. Mandibular anteriors with Geristore applied on occlusal of bicuspids.
Figure 7. Maxillary model: blue die relief on porcelain.
was opened 2 mm at the first molar and bicuspid area. The second molars were contacting in centric at the beginning of the procedure and were still contacting in centric after the porcelain was in place on the six anterior mandibular and maxillary teeth. This 2-mm space is perhaps the amount of tooth structure worn away in the past 10-15 years. The next problem to be resolved was how to keep teeth from contacting in the first molar bicuspid areas. Traditionally, in order to maintain the vertical dimension, a bite plate would be made. However, since Tenure and Geristore (Den-Mat),a hydrophilic self-adhering restorative, can bond to worn surfaces on elderly patients, it was decided to restore the mandibular arch with Geristore using the core build-up technique for adding material to mandibular bicuspids and &st molar (Fig. 10). The occlusal surfaces of the maxillary bicuspids were treated first with Tenure. Next,Truevitality (DenMat), a self-cured, heat-cured, light-cured resin system, was applied as if it were a wax mush bit. A separating media was placed on the mandibular (glycerin), and the patient was instructed to close in centric. While the patient was closed, the Truevitality was lightcured. After the resin was set, the patient was instructed to open and the correct anatomic contour was installed, taking care not to touch the areas of centric contact in the fossa areas. When the contouring was complete, the patient now had a resin system that could easily be removed to maintain the vertical: however, because of the cuspid-guidance and anterior disclusion (porcelain-on-porcelain),no wear will take place on the resin of the posterior teeth because of the protection of the anterior segment. Figure 11 demonstrates the occlusal view of the teeth restored with porcelain and TrueVitality. Figures 12 and 13show the lateral occlusion on both sides, and Figure 14 shows the anterior disclusion. Figures 15 and 16 demonstrate that the
8* Labiallengthening ofmandibular tee*with ‘emate Porcelain Laminate on model.
Pyeure 9. Cerinate porcelain V-shaped crown lengthening maxillary teeth.
98
Restoring the Worn Dentition
Figure 11. Occlusal \dew of maxillary teeth with porcelain installed on anteriors and Truevitality resin on bicuspids.
Figure 14. Patient with anterior disclusion.
Figure 12. Patient in right working.
Figure 15. Patient restored vertical dimension 2.5 mm in centric.
pisnre 13. Patient in left working.
Figure 16. Close-up of restoration, in centric.
99
'The porcelain bonding technique used in this study relies on two important factors. Firstly. the porcelain must have enough strength to withstand the occlusal forces in addition to having high esthetic results. Secondly. since there is a large amount of exposed dentin, the bonding materials must bond strongly to dentin and have negligible film thickness. In addition, the luting agent must offer high strength to prevent fracturing of the porcelain. The porcelain used in this case was Cerinate porcelain (Den-Mat).This patented porcelain exhibits higher strengths, greater translucency, and demonstrates moderate thermal expansion (12x10 C Recently, Wassenaar reported the flexural strength of several porcelains.6The flexural strength (in MPa) of Cerinate is 124, Vitadur N (Vita - a n opaque aluminous porcelain) is 112, and Mirage Body (Chameleon Dental Products) is 60.6 Ultra-Bond is a n Amencan Dental Association certified Type I1 (Specification 27) composite restorative that lutes and bonds any type of porcelain restoration. The uniqueness of Ultra-Bond is that it contains a patented curing system-a photo-initiated dual cure that is light cured and chemical cured. Compared with typical dual-cure systems that start curing as soon as two parts are mixed, and cure faster upon the initiation of light, Ultra-Bond will not begin to cure when the two parts are mixed. It begins when the material is exposed to a strong light and stops curing only when all material has been polymerized. The clinical significance of this curing system is that it gives the dentist a longer working time (approximately 30 minutes) and the opportunity to do multiple laminate placement.' A recent study showed that a porcelain restoration using Cerinate porcelain and Ultra-Bond achieved 100 percent survival after thermal stressing in lab testing.8 Long-term clinical studies support the reliability of Cerinate and Ultra-bond restorations."1* The bonding materials used in this study were Tenure and Ultra-Bond. Many studies report that Tenure has the highest bond strength, l 5 . I 8 good microleakage resistance, and excellent b i ~ c o m p a t i b i l i t y .Ten~~.~~ ure is a n all liquid chemical-cure system and has a very thin film thickness.25 Unlike some resin-based lightcuring systems (e.g., Scotchbond 2[3Ml, or Prisma 2 and Prisma 3 [L.D. Caulk/Dentsply]), which could not be used under porcelain bonded restorations because they are light cured, the porcelain is quite thick in some areas thereby reducing the light energy available to polymerize the Ultra-bond, and have thick film thicknesses. Ultra-Bond also has better matched coefficient of thermal expansion than typical low viscosity luting agents. Tenure is an ideal bonding agent for use with bonded porcelain restorations because it is a self-cured, all liquid system. The wear on posterior occlusal surfaces was restored by using Geristore and TrueVitality. Geristore was applied directly to the worn dentition instead of a prepared cavity. Geristore is a cross product of glass-
patient occludes in centric. Comparing the original photograph nith the finished result. the porcelain restoration increased the length of the teeth and improved the overall esthetics. The patient has been observed monthly for 12 months, has had no failures, and has noTMJ problems. At a later time, the posterior segment will be restored uith a combination ofcast gold and bonded porcelain on the occlusal surface.
DISCUSSION The primary causes of tooth loss are caries, periodontal disease, and wear. Increasing dental awareness among the population has significantly reduced caries and periodontal problems, resulting in a greater proportion of the population retaining their teeth well into adult life. This increasing aged population has borne increasing clinical cases of tooth wear caused by attrition, abrasion. and erosion. Attrition is the wearing away of the tooth surface by tooth-to-tooth contact; abrasion is tooth surface loss caused by the introduction of abrasive substances, materials, or habits into the mouth. Erosion is the loss of tooth substance due to acid. The severe wear in this case was caused by a combination of attrition and abrasion. it was interesting to learn that the patient's cousin, who is about the same age, had the same type of worn dentition. The treatment. however, was complete teeth extraction and complete denture restoration. The anterior worn dentition was restored with a porcelain bonding technique that required very minor tooth reduction and no shoulder preparations. Porcelain laminates, V-shaped porcelain crowns, and porcelain pieces were fused to the tooth structure with Tenure bonding agent and Ultra-Bond restorative. Cuspid-guided occlusion was also established. Ibsen first reported a technique utilizing bonded porcelain restorations to achieve cuspid-guided o c c l ~ s i o nIt. ~is well accepted that cuspid-guided occlusion can protect teeth from wearing.4 Cuspid-guided occlusion with bonded porcelain functions by bonding porcelain pieces to the lingual maxillary cuspids, and porcelain laminates were bonded to the labial mandibular cuspids. At this time. when the patient closes in centric, the only contacts are on cuspids. Then selective grinding is used to achieve a uniform contact on all dentition in centric. The bonded porcelain pieces to the lingual maxillary cuspids provides a porcelain slide that contacts the porcelain laminates bonded to the labial incisal of the mandibular cuspids. This slide path technique provides a constant porcelain-to-porcelain contact. When the teeth move to lateral, the posterior teeth separate, which means that further wear will no longer occur as the teeth separate and they slide out of centric due to the eccentric contact of porcelain on maxillary and mandibular cuspids. 100
Restoring the Worn Dentition
ionomer and composite resin. It adheres to all intraoral surfaces without a separate bonding agent.26It also releases fluoride, which could be helpful to prevent caries, and it is visually translucent.
9. Jordan R. Suzuki M, Senda A. Clinical evaluation of porcelain laminate veneers: a four year recall report. J Esthet Dent 1989: 1:12&-132. 10. Strassler HF. Nathanson D. Clinical evaluation of etched porcelainveneersoveraperiodof 18to 42 months. J Esthet Dent 1989: 1:21-28. 11. Christensen GR, Christensen RP. Porcelain veneers-two years of clinical sendce. J Dent Res 1990; 69:303. Abstract 1553. 12. Griswold W. Gunderson R, Strassler H. Thompson VP. One to two year clinical evaluation of porcelain veneers. J Dent Res 1991: 70:386. Abstract 960. 13. Ibsen RL, Strassler H. A n innovative method for fixed anterior tooth replacement utilizing porcelain veneers. Quintessence Int 1986: 17:455-459. 14. Jenkins C. Aboush Y. Clinical durability of porcelain laminates over 8 years. J Dent Res 1981: 60: 1081. 15. Barkmeier WW, Cooley RL. Resin adhesive systems: in vitro evaluation of dentin bond strength and marginal microleakage. J Esthet Dent 1989: 1:67-72. 16. Wieczkowski G, Yu X Y , Joynt RB. Davis EL. Dentin bonding strength in a three dimensional cavity preparation. J Dent Res 1990: 69: 116. Abstract 62. 17. Stewart BL. Harcourt J K , Tyas MJ. Comparison of dentine bond strength to dentine in cavities restored before and after extraction. J Dent Res 1990; 69:945. Abstract 99. 18. Golub-Evans J . Battle of the bonds: dentists compare dentin bonding agents. Dentist 1990: July/August: 1-3. 19. White SN. Sorensen JA, Kang SK, Caputo AA. Microleakage of new luting agents. J Dent Res 1990: 69:173. Abstract 514. 20. Lynch E. Samarawickrama D. Auger D. Artificial lesion formation around restorations in tooth roots. J Dent Res 1989: 68:573. Abstract 119. 21. Yu X Y , Wieczkowsld G. Davis EL, Joynt RB. The influence of finishing technique on microleakage. J Esthet Dent 1990: 2~142-145. 22. Yu X Y , Davis EL, Joynt RB.Wieczkowski G Jr. Evaluation of microleakage in Tenure-based restorations. J Esthet Dent 1990: 2:145-147. 23. Li Y, Noblitt TW. Dunipace AJ,Stookey GK. Evaluation of mutagenicity ofrestorative dental materialsusingtheAmes salmonella/microsome test. J Dent Res 1990: 69: 1 1881192. 24. Waknine S. Gable P, Schulman A. Physicomechanical, adhesion and cytotoxicity characterization of eleven commercial dentin adhesives. J Dent Res 1989; 68:375. Abstract 1546. 25. Ibsen RL. Glace WR.Bond strength of a low film thickness oxalate resin cement. J Dent Res (in press). Presented a t the San Francisco AADR 1989. 26. Pacropis DR, Ibsen RL. Studies on a fluoride releasing adhesive to various substrates. J Dent Res 1991: 70:479. Abstract 1701.
CONCLUSIONS Using a combination of bonded porcelain and specialized resin bonded systems, a practical, simplified method of restoring wear, preventing wear. strengthening tooth structure, and improving esthetics has been presented. This method could also be used to eliminate the need for mouthguards as the posterior teeth will not be able to contact any more except in centric. The average practitioner who uses proper materials and understands occlusion can offer this treatment to their patients who have varying degrees of wear.* High strength porcelains are traditionally opaque and made from aluminum oxide. Cerinate Porcelain was selected because, in the study by Wassenaar, it has flexural strengths of opaque porcelains but is translucent. This eliminates the necessity for excessive reduction of tooth structure required by aluminous opaque porcelains. *A video tape demonstrattng this technique is available by contacting the author.
REFERENCES 1. Shillingburg HT, Hobo S , Whitsett LD. Fundamentals of flxedprosthodontics. 2ndEd. Chicago: Quintessence, 1981. 2. Rawlinson A. Winstanley RB. The management of severe dental erosion using posterior occlusal porcelain veneers and an anterior overdenture. Restor Dent 1989: 4:1O-16. 3. Ibsen RL, Yu XY. Establishing cuspid-guided occlusion with bonded porcelain. J Esthet Dent 1989; 1:8O-85. 4. Goldstein GR. The relationship of canine-protected occlusion to a periodontal index. J Prosthet Dent 1979: 41: 277-283. 5. Chadwick TC. Ibsen RL. Properties of a new porcelain for veneers, inlays and crowns. J Dent Res 1989; 68:956. Abstract 712. 6. Wassenaar P. The new porcelains--Are they any better? Aust Dent J 1990; 4(Suppl):19-25. 7. Putter H. Ibsen RL. Simultaneous placement of multiple porcelain veneers. J Esthet Dent 1990; 2:67-69. 8. Sorenson J, Kang SK, Avera SP. Porcelain composite interface microleakage withvarious porcelain surface treatments. J Dent Res 1990; 69:359. Abstract 2008.
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