Apexification Outcomes in the United States: A Retrospective Cohort Study

Introduction: This epidemiological analysis used procedure codes from dental insurance claims data to identify apexification cases and evaluate survival at the tooth-level. Methods: Dental insurance claims data from New York State (2006–2019) and Massachusetts (2013–2018) were used in an observational, retrospective cohort study to evaluate the provision and treatment outcomes of apexification. Statistical analyses included Kaplan–Meier survival estimates and Cox proportional hazards regression. Cox proportional hazard regression was used to evaluate the hazard of adverse event occurrence by age, gender, tooth type, placement of permanent restoration, and dental provider type. A sensitivity analysis evaluated potential bias in the survival estimates and adjusted hazard ratios (aHRs) due to differential loss to follow-up. Robust standard errors were used to account for potential dependence between teeth within an individual. Results: The analytic cohort of 575 individuals included 632 teeth, with an average follow-up time of 64 months. The survival rates of apexification procedures were 95% at 1 year; 93% at 2 years; 90% at 3 years; and 86% at 5 years. Tooth retention following apexification was 98% at 1 year; 96% at 2 years; 95% at 3 years; and 90% at 5 years. Tooth type and subsequent placement of a permanent restoration were significant predictors of survival after apexification. Conclusions: The procedural and tooth survival outcomes of apexification were high and comparable to studies that analyzed clinical data on tooth survival following apexification.