Related Experiment Video
Updated: Aug 13, 2026
Guided Endodontics: Three-Dimensional Planning and Template-Aided Preparation of Endodontic Access Cavities
Published on: May 24, 2022
Periapical Healing, Event-Free Survival, and Associated Factors Following Non-Surgical Endodontic Retreatment: An
Adam Sgro1, Maziar Ebrahimi Dastgurdi1, Mahshid Sheikhnezami1
1Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.
Introduction:
Despite favourable outcomes of non-surgical endodontic retreatment (NS-ReTx), treatment decisions for previously treated posterior teeth with apical periodontitis remain inconsistent. This ambispective cohort study evaluated NS-ReTx outcomes in posterior teeth.
Methodology:
Permanent posterior teeth undergoing NS-ReTx in a residency program (2010-2023) with ≥24-month follow-up or an untoward event were included; otherwise, recall was attempted. Teeth were classified as healed, healing, or diseased. Periapical healing was defined using strict and loose criteria, and event-free survival as time to reintervention or last event-free follow-up. Analyses used logistic regression and Kaplan-Meier methods (α = 0.05).
Results:
Periapical healing analyses included 423 teeth (367 patients; median follow-up 3.7 years), comprising retrospectively (n=276; median follow-up 3.4 years) and prospectively (n=147; median follow-up 4.3 years) ascertained subgroups. Overall strict/loose periapical healing rates were 82.7%/89.8%, compared with 80.8%/87.0% and 86.4%/95.2% in the retrospective and prospective subgroups, respectively. Periapical healing rates were higher among teeth with longer follow-up. Absent or smaller preoperative periapical radiolucency (PARL) and adequate-quality final restorations were associated with improved strict periapical healing. Survival analyses included 480 teeth (417 patients). Kaplan-Meier estimated event-free survival was 96.5%, 94.5%, and 92.7% at 2, 4, and 6 years, respectively. The overall crude event-free survival rate was 93.3% with a median follow-up of 3.3 years.
Conclusions:
Contemporary NS-ReTx in posterior teeth showed high periapical healing and event-free survival. Absent or smaller PARL and adequate-quality final restorations were associated with improved periapical healing. These findings should be interpreted considering potential selection bias from incomplete long-term follow-up.
