Survival of surgical endodontic treatment performed in a dental teaching hospital: a cohort study

Aim To assess the survival function of surgical endodontic treatment performed at least 1 year before in a dental teaching hospital. Methodology A total of 194 teeth surgically treated between 1991 and 2001 were recalled and examined clinically and radiographically using a set of strict criteria. The Kaplan-Meier method and log rank test were used to evaluate the survival time. Confounding factors were examined by Cox regression analysis. Results The median survival time of the 154 first-time surgically treated teeth was 92.1 months (95% CI: 40.9-143.4) and that of the 40 resurgery cases was 39.1 months (95% CI: 6.1-72.1) up to the date of recall. There was a significant difference in the length of survival between the two groups. For those first-time surgery cases, the preoperative marginal bone loss and the operator had a significant influence on the survival time (P < 0.05). Conclusions The survival of surgical endodontic treatment declined nonlinearly with time. The preoperative marginal bone loss, operator and resurgery were important factors affecting the survival of this treatment modality.