A RETROSPECTIVE CLINICAL-EVALUATION OF RESIN-BONDED BRIDGES INSERTED AT THE ADELAIDE-DENTAL-HOSPITAL

The clinical performance of resin-bonded Rochette and Maryland bridges inserted by various operators at the Adelaide Dental Hospital is repo rted. Thirty--four Rochette bridges (30 anterior, 4 posterior) and 228 Maryland bridges (150 anterior, 78 posterior) were assessed. Clinical data were compiled on types of bridge failure, factors influencing br idge retention, and the effects of the prostheses on abutment teeth an d supporting tissues. The failure rate for Rochette bridges over 6 yea rs was 75 per cent with a median survival of 2.14 years. Debonding occ urred in 70 per cent of bridge failures. The failure rate for Maryland bridges over 5 years was 42 per cent with a median survival of 2.60 y ears. Pontic fracture (29 per cent) and debonding (20 per cent) were t he main failures observed. Porcelain pontics performed significantly b etter than the processed hybrid resin pontics (P < 0.01). The main rea sons for debonding included occlusal stresses, non-retentive bridge de signs and resin cement failure. A life-table analysis showed no signif icant difference in the overall cumulative survival rates between Roch ette and Maryland bridges. Bridge design and the choice of pontic mate rial and resin cement emerged as significant factors influencing the s uccess rate of the bridges examined.