Prognostic factors and primary healing on root perforation repaired with MTA: a 14-year longitudinal study

Introduction Few data are available on the long-term efficacy of mineral trioxide aggregate (MTA) in treating root canal perforations. This prospective cohort study builds on a previously reported trial to determine the outcome for teeth with root perforations treated with orthograde MTA after longer follow-up and identify potential prognostic factors. Methods A prospective cohort study was performed, enrolling (1999-2009) patients with a single dental perforation treated with MTA. Preoperative, intra-operative, and postoperative information was evaluated, and the outcomes were dichotomized as healed or non-healing. Patients were followed-up yearly until 2018 for a maximum of 17 years post-treatment, with controls carried out until 14 years. Clinical and radiographic outcomes were evaluated using standardized follow-up protocols. Results Of the 124 enrolled patients (median age 36.5 years, 53.2% male), 115 were healed at the first (n=110, 89%) or second (n=5, 4%) annual post-treatment check-up, while 9 subjects (7%, 4 females 18 - 65 YO) did not heal. Characteristics significantly associated with non-healing were gender, positive probing, size, and perforation site. Perforations recurred in 48 teeth during the follow-up with the estimated probability of reversal at 5, 10 and 14 years of 6% (95% CI, 2-10%), 30% (95%CI, 20-38%) and 62% (95% CI,46-73%), respectively. Positive probing had a higher reversal risk (HR=3.3, p≤0.001), and perforations >3mm were more likely to have a reversal (HR=4.1, p<0.001). Conclusions The risk of reversal for healed MTA-treated root canal perforations, initially relatively low, vastly increases over time.