The aim of this study is to assess the influence (i.e. type and timing) of post-endodontic restorations on the survival of root canal-treated teeth and to determine the influence of patient-, tooth-, treatment-, and restoration-specific parameters on longevity.

Patients who received a root-canal treatment between 1998 and 1999 with subsequent placement of an indirect restoration (e.g. crown, partial crown) will be retrospectively analyzed. Patient-, tooth-, treatment-, and restoration-specific parameters will be obtained from digital and paper-based dental records.

Survival and success of the root-canal treatments will be assessed using Kaplan-Meier statistics. Mean annual failure rates (mAFR) and median survival time will be calculated (Kaplan-Meier statistics). Potential predictive factors will be tested using log-rank tests and multi-variate Cox-regression analysis.

Inclusion Criteria:

• Patients who received a root-canal treatment followed by the placement of an indirect post-endodontic restoration (e.g. partial crowns, crowns) within the Department of Preventive Dentistry, Periodontology and Cariology between 1998 and 1999.

Exclusion Criteria:

• None.

Patients who received a root-canal treatment followed by the placement of an indirect post-endodontic restoration (e.g. partial crowns, crowns) within the Department of Preventive Dentistry, Periodontology and Cariology between 1998 and 1999.