Long-term Success and Survival of Endodontic Microsurgery.

Introduction: Healed rates of endodontic microsurgery (EMS) may decrease over time, but research on the long-term outcomes is scarce. The aims of this retrospective cohort study were to evaluate the 5- to 9-year healed and survival rates of EMS, to identify associations between prognostic factors and healing status, and to compare the short-term (1- to 2-year) with long-term (5- to 9-year) outcomes.

Methods: One hundred fifty-one eligible patients (166 teeth) who underwent EMS in 2007-2010 were invited for a follow-up examination. Eighty-three patients (94 teeth) participated in the study. Survival status and reasons for extraction of all teeth were determined, and survival rates were calculated by Kaplan-Meier analyses. Outcomes were determined on the basis of clinical and radiographic findings and associated with potential prognostic variables via multivariate Cox regression analyses.

Results: Thirty-two teeth were extracted: 6 because of endodontic failure, 20 for unrelated reasons, and 6 for unknown reasons. Outcomes were categorized as healed and not healed. Multivariate analysis revealed that adjusted hazard ratio for failure was 5.95 times higher (95% confidence interval, 1.54-22.91) for teeth treated with intermediate restorative material than with mineral trioxide aggregate and 3.38 times higher (95% confidence interval, 1.05-10.9) for teeth with no known history of nonsurgical retreatment. Teeth classified as healed in the 1- to 2-year review mostly remained healed at 5- to 9-year review (45/48 teeth); those with uncertain healing had varied outcomes at long-term review.

Conclusions: EMS results in high long-term healed (78.3%, 72/92 teeth) and survival (95.2%) rates. Root-end filling material and nonsurgical retreatment before EMS may influence the long-term outcome.