Longevity of fixed partial dentures

Statement of problem. The anticipated length of service and reasons for replacement of fixed partial dentures (FPDs) are a frequent inquiry by patients. Previous reports have provided limited information on material and techniques used in restoration or standards in evaluations of restorations at delivery. Purpose. This study determined the reasons for failure and length of service for FPDs delivered with specific clinical, radiographic, and laboratory procedures. Methods. A clinical and retrospective chart review was conducted on all patients with FPDs who were treated in the prosthodontic clinic at the University of Iowa Hospital for routine dental hygiene recalls during a 6-month period. Fifty patients were examined with a total of 89 FPDs. Of the 89 FPDs, 13, or 15%, were identified as failures or had been replaced because of failure. Dental caries was the most frequent cause of failure (38%), followed by periapical involvements (15%), perforated occlusal surfaces (15%), fractured post and cores (8%), defective margins (8%), fractured teeth (7%), and porcelain failures (8%). The mean length of service for failed FPDs ranged from 16.0 years, because of failure from dental caries, to 4.1 years, because of a fractured post and core. Results. A linear regression model of years in service against number of failed FPDs indicated that the number of years in service provided no information on predictability of failure for FPDs. Conclusions. This study supported previous reports of dental caries as the primary cause for failure of FPDs, but specific radiographic, clinical, and laboratory procedures can increase the length of service of these restorations. (J Prosthet Dent 1997;78:127-31.)