Resin-bonded bridges by dental undergraduates: three-year follow-up

This study was conducted to evaluate performance and longevity of resin-bonded bridges in patients treated by undergraduate dental students. A total of 62 bridges had been constructed for 53 patients by the students at the School of Dentistry, Karolinska Institute, between 1989 and 1997. After a mean observation period of 35.3 months retention had been lost in 13.6% of 59 bridges examined (4.6% per year). The debonding rate was greater in the mandible (8.3 %/year) than in the maxilla (2.7 %/year), and greatest in the mandibular anterior region (13.4%). Thirty-nine patients with 46 bridges (27 maxillary and 19 mandibular bridges), underwent more detailed clinical examination. No significant differences in bleeding and pocket depth were found between abutment teeth and controls. Bleeding was more frequent at the approximal than the lingual surfaces of the abutment teeth. A questionnaire revealed high patient satisfaction, the resin-bonded bridges meeting their expectations. The study suggests that resin-bonded bridges are an acceptable alternative to conventional bridges. Successful outcome is dependent on stringent case selection, an abutment preparation designed to establish retention form, and meticulous bonding procedures.

Patients' satisfaction in two long-term clinical studies on resin-bonded bridges

This study aimed to evaluate patients' satisfaction with resin-bonded bridges and the effect of failures on the degree of satisfaction. In two clinical trials, 358 patients completed guided questionnaires at regular recalls (n=1484). In this way, data regarding 'overall function', 'colour', 'shape', 'functional changes', 'complaints' and 'recommendation to other patients' were obtained. The scores of each criterion were evaluated for the variables 'trial', 'gender', 'time after placement' and 'failure', using 4-way ANOVA. Encountered failures were rated using a 'failure severity scale'. For all combinations of measurement periods, the changes in patient's opinions were calculated and the differences tested using the paired t-test. Overall satisfaction was correlated with 'colour', 'shape' and inversely correlated with 'complaints' (r>0.34; all P<0.005). No statistical differences were found between males and females. No significant changes were observed in patient satisfaction over time. Failures influenced the failure sensitive variables 'functional changes' and 'avoidance of load'. The z-scores were independent of the severity of the failures (r<0.13; all P>0. 10). The degree of patient satisfaction with resin-bonded bridges appeared to be high and did not seem to be influenced by the occurrence of failure.

Comparison of resin-bonded prosthesis groove parallelism with the use of four tooth preparation methods

STATEMENT OF PROBLEM

A precise preparation is required to develop resistance form resulting in mechanical stability of the framework for resin-bonded prostheses (RBPs).

PURPOSE

The effects of 4 methods of tooth preparation (freehand, guiding pin, extraoral parallelometer, and intraoral parallelometer) on the deviation of proximal grooves from a preestablished path of insertion (guide planes) were investigated under clinical conditions.

MATERIAL AND METHODS

Tooth preparation of proximal grooves was performed by 32 dentists on resin substitutes of posterior segments intraorally with a single test patient. A Latin-square randomized cross-over design was selected as the experimental design.

RESULTS

The significant least angular deviation of proximal grooves from path of insertion was achieved with an intraoral parallelometer (mean +/- SD 3.15 +/- 1.67 degrees). Compared with freehand tooth preparations (4.37 +/- 2. 11 degrees), neither use of a guiding pin (4.10 +/- 1.62 degrees) nor an extraoral parallelometer (5.06 +/- 2.33 degrees) improved the results.

CONCLUSION

Divergence of guiding grooves from path of insertion was reduced with the use of an intra-oral parallelometer. This should improve mechanical stability of posterior RBPs.

The provision of resin-bonded bridgework within the General Dental Services 1987-1997

The purpose of this study was to investigate the performance of resin-bonded bridgework provided within the General Dental Services of the National Health Service. The basic procedure involved analysis of data collected from the administering authorities in England, Wales and Scotland between 1987 and 1997. These figures included the cost of the provision of such bridgework and the incidence and cost of refitting bridges which had become debonded in service. The investigation found that while the number of resin-bonded bridges provided had peaked in the early 1990s the number of claims for rebonding was still increasing at a high rate. In the most recent year of the study (1996/97) the number of claims for rebonding bridges was 50% more than the number of bridges actually fitted during that year. It was concluded that resin-bonded bridgework provided under the General Dental Services of the National Health Service was experiencing a high failure rate and that this problem was worthy of further investigation.

Photoelastic stress analysis in a pier retainer of an anterior resin-bonded fixed partial denture

STATEMENT OF PROBLEM

A clinical situation may arise with 2 edentulous spaces and a single intact pier tooth. A dentist may restore these edentulous spaces with a long span resin-bonded fixed partial denture using the pier and the 2 terminal abutments for bonding.

PURPOSE

This study analyzed the stresses induced in a pier retainer of an anterior resin-bonded fixed partial denture and determined the effect on a pier abutment.

MATERIAL AND METHODS

Photoelastic materials were selected to represent the relative stiffness of 3- and 5-unit resin-bonded fixed partial dentures. The models were scaled to x2.5 to enhance visual analysis of the stress pattern.

RESULTS

Isochromatic fringes indicated a stress magnitude at the proximolingual areas of the pontic in the 3-unit resin-bonded fixed partial denture. In the 5-unit resin-bonded prosthesis, the stress pattern appeared to involve the entire surface of the pier retainer.

CONCLUSION

The use of pier abutments should be avoided and it is more favorable to use 3-unit resin-bonded fixed partial dentures.

Risk factors and multiple failures in posterior resin-bonded bridges in a 5-year multi-practice clinical trial

OBJECTIVES

A randomized controlled clinical trial was undertaken, to study the influence of some patient- and operator-dependent variables on the survival of posterior resin-bonded bridges (PRBBs) and to assess the survival of replacement' PRBBs. This report contains some of the results of the 5-year analysis.

METHODS

Survival was defined at three levels: (1) complete survival (without any debonding), (2) functional survival (i.e. survival after one loss of retention) and (3) replacement survival (survival of 'replacement' PRBBs, inserted after rebonded bridges suffered a second dislodgement). Potential risk factors were analysed with Cox's proportional hazards model and differences were tested for significance with the Breslow test. Observed effects are expressed as conditional-relative-risk (CRR). Survival of 'replacement' PRBBs was assessed with the Kaplan-Meier method.

RESULTS

Factors showing significant influences on complete survival were: 'location' (highest risk for mandibular PRBBs: CRR = 2.2), 'aetiology' (higher risk in treatment of aplasia: CRR = 2.9), and 'time of existence' (open spaces existing less than 2 years before insertion of PRBB: CRR: 2.0). The factor 'large open spaces in the mandible' was a risk for both complete and functional survival (CCR values 3.1 and 3.5, respectively). The survival of mandibular and maxillary 'replacement' PRBBs after 5 years was 19 +/- 7% and 31 +/- 18%, respectively.

CONCLUSIONS

Risk factors for PRBBs were: 'location', 'aetiology', 'time of existence', 'isolation method' and 'large open spaces in the mandible'. Mandibular 'replacement' PRBBs showed such an unacceptably low survival rate that fabrication is not recommended.

Ten-year clinical and microscopic evaluation of resin-bonded restorations

A clinical recall was conducted for 103 patients who were functioning with resin-bonded restorations for approximately 10 years. The purpose of this study was to evaluate marginal adaptation of the cast metal retainers. Following clinical evaluations, replicas of incisal and occlusal margins were examined in the scanning electron microscope to determine marginal separation and microscopic patterns of the resin composite interface between metal and tooth. Anterior abutments exhibited better clinical adaptation and fewer voids and debonds than did posterior abutments. Larger microscopic marginal separations were associated with those retainers that had clinically detectable voids or defects.

Panavia/sandblasted resin bonded prostheses: a five year retrospective study

The authors feel that this study suggests that the Panavia/sandblasted retention method, with its low debond rate, is a viable method for luting resin bonded prostheses. The authors wish to acknowledge the services of Ms. Jane Jakobsen (statistician) and Ms. Connie Norton (secretary) who made significant contributions to the completion of this article. Their help was much appreciated.

A longitudinal study of resin-bonded prostheses

Resin-bonded fixed partial dentures, without definitive tooth preparation and current resinous cements and perceptive treatment, have had an inordinate number of dislodgments in initial restorative efforts. A longitudinal examination of resin-bonded prostheses was performed after a mean observation time exceeding 6 years. To prevent stress fatigue fractures of the cement bondings, one proximal groove was prepared in dentin for each anterior abutment and the inner surfaces of the frameworks were silicoated. Five of 34 prostheses debonded, and the bond strength between resin and high gold alloys was too low to resist fatigue fractures during this study. The results of this study and other reports suggested a need for increased retention and resistance form of the frameworks to improve longevity of resin-bonded prostheses.

The clinical performance of cantilevered resin-bonded bridgework

OBJECTIVES

The technique of resin-bonded bridgework is a well-accepted clinical technique to replace missing teeth. This study assesses the clinical performance of cantilevered resin-bonded bridgework provided in a university teaching hospital environment.

METHODS

One-hundred and twelve patients who had a total of 142 cantilevered bridges were either examined or completed a questionnaire regarding their bridgework. The following data were recorded for each resin-bonded bridge: gender of patient, age at bridge cementation, date of initial cementation, tooth replaced, abutment(s) involved, and grade of clinician responsible for the provision of the bridge. Details of the incidence of debonding with date(s) and the subsequent treatment in relation to the debonded resin-bonded bridge were recorded. The subjects examined indicated their degree of satisfaction with their bridgework on a visual analogue scale.

RESULTS

There were 112 patients with a total of 142 bridges, 116 (82%) maxillary and 26 (18%) mandibular. The mean length of clinical service was 36.2 months (s.d. 17.2 months). Only single pontics were included in the bridges, with almost half (49%) replacing a lateral incisor. Of the cantilever resin-bonded bridges studied, 88% remained bonded over the period of the study. A success rate of 94% is reported.

CONCLUSION

This study confirms the clinical success of cantilever resin-bonded bridges particularly in the replacement of maxillary lateral incisors, maxillary premolar and permanent mandibular teeth.

Risk of debonding in three-unit resin-bonded fixed partial dentures

Resin-bonded fixed partial dentures are considered practical and conservative but have not always enjoyed longitudinal success. The long-term survival of 1637 three-unit resin-bonded fixed partial dentures was analyzed. A multistate analysis that included parameters such as debonding, rebonding, or renewal of the restoration was used. Five years after insertion 66.1% (+/- 3.7%) of the originally inserted prostheses remained in place. If additional rebonding was computed, the probability of survival was 82.0% (+/- 3.0%). Reconstruction of the metal frame after one or more dislodgements raised the success rate to 87.1% (+/- 2.6%). Rebonded resin-bonded fixed partial dentures developed a greater risk of debonding. The risk of failure for refabricated fixed partial dentures was similar to that of the originally inserted resin-bonded fixed partial dentures. There were no signs of greater caries incidence after multiple recementation procedures.

Fixed bonded prosthodontics: a 10-year follow-up report. Part II. Clinical assessment

The survival rates of resin-bonded fixed partial dentures, bonded splints, and bonded combination splints and fixed partial dentures (splints with pontics replacing one or two missing teeth) were determined. For statistical analysis, the splints and splint-prostheses were combined into one group. The average age of all devices combined was 5.7 years. Eleven of 145 resin-bonded fixed partial dentures failed; the survival rate was 83.0%. There was no statistically significant difference between the survival rates of prostheses, whether bonded to prepared teeth or unprepared teeth. Fifteen of 98 splints and splint-prostheses failed. The survival rate of splints and splint-prostheses bonded to prepared teeth (71.6%) was higher than that of splints and splint-prostheses bonded to unprepared teeth (53.6%). To determine the continuing relevance of resin-bonded prostheses, the number of instances in which implant dentures could have been used was calculated. Implant treatment would have been possible in only 14 or 98 cases.

Failure rates of restorations for single-tooth replacement

Failure rates of traditional fixed partial dentures, resin-bonded prostheses, and implant restorations for the replacement of a single missing tooth are compared in this literature review. A lack of documented longevity studies involving conventional fixed partial dentures makes failure rates difficult to determine. Reported failures ranged from only 3% over 23 years to 20% over 3 years. The major causes of loss were caries and endodontically and periodontally related complications. Research concerning resin-bonded fixed partial dentures was more prevalent, but indicated that overall retention of these prostheses may be unpredictable. Failure rates were quite divergent, ranging from 10% over 11 years to 54% over 11 months. Debonding was the usual cause of failure. Clinical reports of single-tooth implant replacements have followed stricter protocols than the other two alternatives. Short-term studies indicated favorable success rates for these restorations, but these must be confirmed by long-term evaluations. Failures ranged from 9% over 3 years to 0% over 6.6 years. These comparisons should be considered in treatment planning a restoration for the replacement of a single missing tooth.

Analysis of debond rates of resin-bonded prostheses

Debonding rates of 164 resin-bonded prostheses (RBP) placed from 1974 to 1985 were examined at recall. The yearly debond rates were calculated, the cumulative probability of failure was determined for the debonded RBPs, and Weibull distribution parameters were determined. For perforated prostheses, there was a high initial debond rate, followed by slowly decreasing rates for about 5 years. Increasing rates after 5 years indicated the beginning of wear-out. The Weibull parameters for the wear-out period of the perforated prostheses were: characteristic life = 128 (SE = 2) months, modulus = 1.27 (0.06), and threshold parameter = 0. Data were available for etched frameworks for 6 years and showed decreasing debond rates during this time. The characteristic life of the etched bridges was 318 (84) months. The cumulative failure data were also modeled with a cubic polynomial distribution that resulted in a U-shaped hazard function.

Predictions of resin-bonded bridge survivals, comparing two statistical models

The purpose of this study was to compare the predictive accuracy of the standard Weibull distribution model with that of a modification, or mixture model, for resin-bonded etched-metal bridge survivals. A total of 189 bridges placed in adult patients treated by students and staff at a teaching hospital was evaluated over periods of up to 8 years. Survival predictions based on the actual survival data accumulated in 1989 were compared with the later survival data updated in 1992. Comparison of the two fitted Weibull predictive curves with the life table survival estimates from the 1992 updated data demonstrated clearly the improved accuracy of the mixture model for predicting survivals of the resin-bonded bridges in this study.

A longitudinal clinical study of bonded fixed partial dentures: the first 5 years

Etched-metal, composite resin-bonded, fixed partial dentures, as described in the early 1980s, gained an immediate application and popularity in restorative dentistry. This initial report presents the results of the first 5 years of a 10-year longitudinal study of these restorations. A total of 71 fixed partial dentures, ranging in use from 13 to 65 months, that were placed at the University of California, Los Angeles, School of Dentistry using consistent design parameters and restorative techniques have been analyzed. The results of this initial report indicate: (1) bonded fixed partial dentures are technique-sensitive; (2) optimal success requires meticulous attention to procedural detail; (3) anterior bonded fixed partial dentures do not appear to need routine 180-degree-plus circumferential retainer preparation for predictable success; (4) posterior bonded fixed partial dentures appear to require 180-degree-plus circumferential preparation for predictable success; (5) for single-tooth posterior replacements or single-to-double tooth anterior replacements, bonded fixed partial dentures are a viable alternative to conventional fixed partial dentures when intact abutments exist; and (6) most failures occurred within the first year.

Performance of 400 adhesive bridges fitted in a restorative dentistry department

The purpose was to present a descriptive report of the clinical performance of adhesive bridges fitted in a university department of restorative dentistry. The case records of 400 consecutive adhesive bridges fitted between November 1984 and June 1989 in the School of Clinical Dentistry, Queen's University, Belfast were reviewed. The majority of the bridges (66 per cent) were of a fixed-fixed Maryland design; the remainder were Maryland cantilevers (18 per cent), hybrids, i.e. Maryland cantilevers which slotted into conventional units (8 per cent), and Rochette bridges (6 per cent). The mean duration of clinical service at review was 2.7 years. One hundred (25 per cent) of the bridges debonded on at least one occasion. Of the bridges which debonded the average number of debonds was 1.7, with the first debond happening on average 10.7 months after placement (range 1-42 months). Fifty-seven (14 per cent) debonded on one occasion only; 25 (6 per cent) debonded twice and 18 (5 per cent) debonded on three or four occasions. The length of clinical service was a significant factor in relation to debonding. A lower proportion of posterior than anterior bridges debonded and cantilevered and hybrid designs performed well. It is concluded that this investigation confirms the efficacy of resin-bonded bridgework used to replace both anterior and posterior teeth.