Prognostic Factors after Endodontic Microsurgery: A Retrospective Study of 111 Cases with 5 to 9 Years of Follow-up.

[INTRODUCTION] A study was performed of the healing rate of teeth subjected to endodontic microsurgery after a minimum follow-up of 5 years with an analysis of the influence of different pre- and postoperative factors on the outcome.

[METHODS] This was a retrospective study of patients subjected to endodontic microsurgery with the use of mineral trioxide aggregate (MTA) for retrograde filling between January 2011 and December 2015. In patients with multiple treated teeth, only 1 random tooth was selected for the statistical analysis. Clinical and radiographic parameters were used to assess healing. Simple binary logistic regression models were used to analyze the influence of patient age and sex, the type of tooth, prior radiographic lesion size, the presence of a post, the type of restoration, and the apical extent of prior filling of the root canal on the endodontic microsurgery success rate. Two calibrated observers evaluated the periapical radiographs on an independent basis.

[RESULTS] A total of 111 patients (63.1% women and 36.9% men) were included in the study. Of the 111 teeth analyzed, 90 were classified as healed (mean healing rate = 81.1%). Patient age and sex, the presence of a post, the type of tooth, the type of restoration, and the apical extent of prior filling of the root canal had no significant impact on the outcome. Large lesions (>5 mm) were associated with a lower healing rate than smaller lesions, although the difference was not significant. Anterior teeth had a significantly higher healing rate (93.8% maxillary and 100% mandibular) than molars (70.8% maxillary and 57.1% mandibular) (P < .05). The differences between the anterior teeth and the molars were statistically significant.

[CONCLUSIONS] The mean healing rate of teeth subjected to endodontic microsurgery was 81% after 5-9 years of follow-up. The success rate was lower for upper and lower molars than for teeth in the anterior zone, although the sample was small and further studies are needed to establish whether the type of tooth influences the treatment outcome.