Long-term survival of Cerec restorations: a 10-year study

This clinical retrospective study assessed the longevity of CAD-CAM ceramic restorations (Cerec) inserted into the cavities of 95 patients in a private practice in Berlin, Germany. Three hundred and eight ceramic restorations were inserted into cavities in the posterior teeth of 95 patients between 1992 and 1994. One operator placed all restorations in a single sitting. Seventy-four patients, including 226 restorations, returned to the practice for a final examination at the end of 10 years. Reasons for non-attendance include relocation (15), death (2) and personal reasons (4). Again, all examinations were performed by a single examiner, however, not the same dentist who initially treated the patients. Out of the 226 restorations, 39 had been inserted in Class I cavities and 187 in Class II cavities (84 two-surfaces, 103 three or more surfaces). In the latter group, one cusp was replaced in 20 cases and two cusps in three cases. All the restorations were fabricated using Cerec 1 (46 Dicor, 180 Vita Mark II) and cemented adhesively with Vita Cerec Duo Cement in combination with Syntac Classic under a rubber dam. Kaplan-Meier survival analysis was calculated under the following failure-criteria: (1) secondary decay, (2) any kind of loss of the restoration, (3) fracture of the restoration, (4) tooth fracture and (5) marginal gap reaching dentin or base material. For statistical analysis, SPSS 12.0 was used. The survival rate was 94.7% (12 failures) after five years and 85.7% (23 failures) after 10 years. The results of the current study show that the survival rate of Cerec 1 restorations, as applied in this study, are comparable with the survival rates of cast gold restorations.