Survival of crowns and bridges related to luting cements.

The longevity of 782 items of crown and bridgework was investigated in a retrospective study. The effect of different cement lutes was assessed for periods varying from 70 to 89 months using a survival analysis technique. The analysis of all types of restoration showed slightly better survival figures for restorations cemented with polycarboxylate but were not statistically significant when compared with those cemented with glass-ionomer. However, those cemented with polycarboxylate were significantly more successful than zinc phosphate. The restorations cemented with glass-ionomer showed no statistically significant improvement in survival rate compared with those cemented with zinc phosphate. Restorations cemented with zinc/oxide eugenol reinforced EBA cement had the lowest survival rate of the four cement types. Analysis of the survival of crowns alone showed the same ranking of the cements compared with all restorations. Comparison of bridges, ranked those cemented with glass-ionomer above those cemented with polycarboxylate, but not statistically different. Posts cemented with phosphate were ranked first and lasted significantly longer than those cemented with glass-ionomer.