Retrospective analysis on the repair vs. replacement of composite restorations

•Repairs are suitable to increase the survival of restorations.•Longevity of repaired and replaced restorations is comparable.•Longevity depends on various patient- and tooth-related variables. 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. 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