Tooth Survival after Surgical or Nonsurgical Endodontic Retreatment : Long-term Follow-up of a Randomized Clinical Trial

Introduction: The aim of the study was to determine long-term tooth survival after endodontic retreatment and whether the presence of intraradicular posts influences the outcome. Methods: Ninety-five teeth were randomly assigned to surgical or nonsurgical endodontic retreatment. Forty-seven teeth in 45 patients were treated by conventional endodontic surgery and 48 teeth (47 patients) by nonsurgical retreatment, including the removal of intraradicular posts in 37 (77%). The outcome was tooth survival; follow-up continued until the tooth had been extracted, at least 10 years had elapsed since retreatment, the patient declined further follow-up, or the patient died. The Fisher exact test was used to analyze differences between the groups. Results: The median follow-up time was 10.1 years (range, 0.0–15.6 years). The overall survival rate was 76%, with no significant differences in long-term tooth survival between retreatment methods or the presence of an intraradicular post. The reasons for tooth extraction were related to the retreatment method. Vertical root fractures were significantly more frequent in the nonsurgical group when retreatment included post removal (P =.036). Conclusions: There was no significant difference in long-term tooth survival after surgical or nonsurgical retreatment. The presence of intraradicular posts did not affect long-term tooth survival, but for teeth with posts, those retreated nonsurgically were more frequently extracted because of vertical root fractures than those retreated surgically (P =.036). The major limitations of the study were a smaller sample size and the use of outmoded retreatment techniques.