Prognostic Factors and Primary Healing on Root Perforation Repaired with MTA: A 14-year Longitudinal Study

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.

A prospective cohort study was performed, enrolling (1999-2009) patients with a single dental perforation treated with MTA. Preoperative, intraoperative, and postoperative information was evaluated, and the outcomes were dichotomized as healed or nonhealing. Patients were followed up yearly until 2018 for a maximum of 17 years after treatment, with controls carried out until 14 years. Clinical and radiographic outcomes were evaluated using standardized follow-up protocols.

Of the 124 entrolled patients (median age = 36.5 years, 53.2% male), 115 were healed at the first (n = 110, 89%) or second (n = 5, 4%) annual posttreatment checkup, while 9 subjects (7%, 4 females, 18-65 years old) did not heal. Characteristics significantly associated with nonhealing 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% confidence interval [CI], 2%-10%), 30% (95% CI, 20%-38%), and 62% (95% CI, 46%-73%), respectively. Positive probing had a higher reversal risk (hazard ratio = 3.3, P ≤ .001), and perforations >3 mm were more likely to have a reversal (hazard ratio = 4.1, P < .001).

The risk of reversal for healed MTA-treated root canal perforations, initially relatively low, vastly increases over time.