Terry R Walton1. 1. University of Sydney, Faculty of Dentistry, Australia. twalton@mail.usyd.edu.au
Abstract
PURPOSE: This study reports on the outcome of 515 metal-ceramic fixed partial dentures (FPD) involving 1,209 abutments and 885 pontics placed by one operator in a specialist prosthodontic practice between January 1984 and December 1997. MATERIALS AND METHODS: Clinical and laboratory protocol was kept constant as much as was practical. Each FPD and abutment was given a subjective prognostic rating at the time of cementation. Patients were recalled in 1993 (review 1) and 1998 (review 2). Clinical examination by the author covered 85% of 342 FPDs at review 1 and 82% of 515 FPDs at review 2. At review 2, 37% had been in clinical service for 5 to 10 years (group b), and 34% had been in service for 10 to 15 years (group c). An objective classification protocol was used to assess outcome. RESULTS: At review 2, the FPDs had failure rates of 2%, 7%, and 11% in groups a, b, and c, respectively. There was a significant increase in the failure rate of group c at review 2 (11%) compared with review 1 (5%). Cumulative survival analysis indicated that FPDs have an expected survival rate of 96%, 87%, and 85% at 5, 10, and 15 years, respectively. The applied prognostic rating proved more accurate as clinical service time increased. Outcome was not related to number of units. Cantilevered FPDs, nonvital abutments, and anterior abutments had significantly greater failure rates. Of initially vital abutments, 2% were subsequently endodontically treated. CONCLUSION: Tooth-supported FPDs have an expected survival rate of 85% at 15 years when the described clinical and laboratory protocol is applied.
PURPOSE: This study reports on the outcome of 515 metal-ceramic fixed partial dentures (FPD) involving 1,209 abutments and 885 pontics placed by one operator in a specialist prosthodontic practice between January 1984 and December 1997. MATERIALS AND METHODS: Clinical and laboratory protocol was kept constant as much as was practical. Each FPD and abutment was given a subjective prognostic rating at the time of cementation. Patients were recalled in 1993 (review 1) and 1998 (review 2). Clinical examination by the author covered 85% of 342 FPDs at review 1 and 82% of 515 FPDs at review 2. At review 2, 37% had been in clinical service for 5 to 10 years (group b), and 34% had been in service for 10 to 15 years (group c). An objective classification protocol was used to assess outcome. RESULTS: At review 2, the FPDs had failure rates of 2%, 7%, and 11% in groups a, b, and c, respectively. There was a significant increase in the failure rate of group c at review 2 (11%) compared with review 1 (5%). Cumulative survival analysis indicated that FPDs have an expected survival rate of 96%, 87%, and 85% at 5, 10, and 15 years, respectively. The applied prognostic rating proved more accurate as clinical service time increased. Outcome was not related to number of units. Cantilevered FPDs, nonvital abutments, and anterior abutments had significantly greater failure rates. Of initially vital abutments, 2% were subsequently endodontically treated. CONCLUSION: Tooth-supported FPDs have an expected survival rate of 85% at 15 years when the described clinical and laboratory protocol is applied.