Retrospective analysis on the repair vs. replacement of composite restorations.

OBJECTIVE: Our retrospective study aimed to assess the impact of repairs on the longevity of anterior and posterior direct composite restorations and to compare longevity of repaired and replacement restorations. METHODS: Patient records were retrospectively screened for anterior and/or posterior composite restorations with 2+ surfaces placed in permanent teeth between 2000 and 2015. During follow-up, repaired and replaced restorations were assessed and mean annual failure rates (mAFR) calculated. Outcome was considered in three levels: Success (no further intervention), survival 1 (first repair=survival, second repair=failure) and survival 2 (more than one repair=survival, all surfaces repaired=failure). Statistical analysis was performed using Kaplan-Meier statistics, log-rank tests, and multi-variate Cox-regression analyses with shared frailty (p<0.05). RESULTS: 8542 initial restorations placed in 3239 patients were included (4.7+/-4.4 years follow-up, 2.5+/-0.7 surfaces). Longevity of initial restorations was prolonged by repair(s) (after 10 years: success: 68.3%, mAFR: 3.7%; survival 1: 77.3%, mAFR: 2.5%; survival 2: 80.4%, mAFR: 2.2%; p<0.001). 616 repaired restorations (4.9+/-4.2 years follow-up, 3.5+/-1.0 surfaces) and 264 replacement restorations (5.6+/-4.1 years follow-up, 3.0+/-0.8 surfaces) were analyzed. Success of repaired restorations amounted to 43.4% after 10 years (mAFR: 8.0%), further repair(s) prolonged survival (survival 1: 65.7%, mAFR: 4.1%; survival 2: 74.8%, mAFR: 2.9%; p<0.001). Success of replacement restorations amounted to 48.6% after 10 years (mAFR: 7.0%), repair(s) prolonged survival (survival 1: 67.4%, mAFR: 3.9%, p=0.044; survival 2: 74.1%, mAFR: 3.0%, p=0.003). SIGNIFICANCE: Repairs are suitable to increase the survival of restorations; repaired restorations last as long as replacements.