Rafael FERNÁNDEZ-GRISALES, Jorge Mario GUTIÉRREZ-GUZMÁN, Diego TOBÓN-CALLE, Luis Gonzalo ÁLVAREZ, Néstor RÍOS-OSORIO
European Endodontic Journal - 2026;11(9):438-447
Objective: To investigate the long-term maintenance of periapical health in healthy teeth after root canal treatment for restorative indications (RCT-FRIs) and to identify factors associated with loss of periapical health over time. Methods: In this prospective cohort study, 206 teeth (406 roots) with normal pulp and periapical status at baseline underwent standardised RCT-FRI. Follow-up included annual clinical and periapical radiographic (PR) assessment; cone-beam computed tomography (CBCT) was performed at baseline and at the corresponding follow-up assessment using standardised limited-field protocols, with follow-up duration varying according to recall attendance and endpoint status. Periapical radiolucency (PARL) was defined as PAI >= 2 on PR and CBCTPAI >= 1 on CBCT. Maintenance of periapical health was analysed using Kaplan-Meier estimates, and study variables were assessed using multivariable Cox proportional hazards models with robust variance estimation to account for clustering. Results: All teeth remained in situ throughout follow-up. Periapical radiolucencies developed in a subset of cases and were consistently associated with clinical symptoms. CBCT identified significantly more PARLs than PR (40/406 roots, 9.8% vs 18/406 roots, 4.4%; exact McNemar test, P < .001). Inter-examiner agreement was excellent for both imaging modalities (Fleiss' kappa = 0.90 for PR; Fleiss' kappa = 0.96 for CBCT). Increasing age, missed canals, inadequate definitive coronal restoration and the presence of an intraradicular post were independently associated with reduced maintenance of periapical health. Kaplan-Meier estimates at 10 years showed that maintenance of periapical health was 95.5% and 92.5% by PR, and 90.1% and 89.0% by CBCT, at the root and tooth levels, respectively. Conclusion: Root canal treatment for restorative indications in healthy teeth was associated with high long-term maintenance of periapical health. Standardized limited-field CBCT provided a more stringent characterisation of periapical status than PR. Long-term outcomes were associated with restorative and anatomical factors.
