Survival of Endodontically Treated Roots/Teeth Based on Periapical Health and Retention: A 10-year Retrospective Cohort Study

Introduction: The purpose of this retrospective longitudinal cohort study was to evaluate the outcome of nonsurgical root canal treatment (NSRCT), expressed as survival for both periapical health and retention of roots/teeth, as determined by clinical evaluation, periapical film/digital radiography (PFR/DPR), and cone-beam computed tomography (CBCT) over 10 years, to determine the prognostic factors that influenced successful treatment outcomes. Methods: A total of 132 teeth (208 roots) with vital pulp received NSRCT at a university clinic. Eighteen factors (preoperative, intraoperative, and postoperative) were documented from the dental records and radiographs. Periapical indices with scores >= 2 (PFR/DPR) and >= 1 (CBCT) indicated the presence of a periapical lesion. Data were analyzed using the Kaplan-Meier test and the Cox proportional hazards regression model (P < .05). Results: The estimated 10-year overall survival rates for periapical health of roots/teeth were 89.4%/88.6% with PFR, 89.4%/89.3% with DPR, and 72.6%/69.7% with CBCT; the survival rate for root/tooth retention was 90.4%/91.6%. Conclusions: The long-term outcome of NSRCT expressed as survival for periapical health was different with each radiographic method. Approximately more than 90% of the roots/teeth were retained for up to 10 years. The prognostic factors for periapical health were the disinfection of gutta-percha, missed canals, age, treatment sessions, and density of root filling (voids); the age and presence of a post were for root/tooth retention.