Retrospective clinical study and survival analysis on partial ceramic crowns: results up to 7 years

The purpose of the present study was to determine retrospectively the clinical performance of 42 all-ceramic partial crowns (PCCs) placed during the past 7 years. All patients (n = 25) with partial ceramic crowns (n = 49) placed by one experienced dentist between 1992 and 1999 were asked to take part in a clinical study, and 22 patients with 42 restorations agreed to do so. All partial ceramic crowns studied were fabricated using the IPS-Empress I all-ceramic system (Vivadent). The following luting composites were used for placing the restorations: 20 (47.6%) Variolink high viscosity (Vivadent), 3 (7.1%) Variolink ultra (Vivadent), 17 (40.5%) Dual Zement (Vivadent), and 2 (4.8%) Compolute (Espe). The partial ceramic crowns were examined clinically using the modified USPHS criteria. Of the 42 restorations, 40 (95.2%) were still in function without any need of replacement. One restoration (2.4%) had failed before starting the clinical study, and another one (2.4%) fractured during the study. Twenty-eight (66.7%) of the partial ceramic crowns evaluated were rated Alpha with respect to marginal adaptation. Twelve (28.6%) restorations were rated Bravo, no Charlie ratings were found and 2 (4.7%) restorations were rated Delta. The Kaplan-Meier analysis was used to calculate the survival rate. The probability of survival (95% confidence interval) for 7 years was 81% (66-96%). These data indicate that partial ceramic crowns may provide successful esthetic restorations in posterior teeth.