ABSTRACT Aim This retrospective cohort study aimed to identify pretreatment prognostic factors for tooth survival in teeth with endodontic‐periodontal lesions (EPLs). Materials and Methods Teeth with EPLs treated according to a standardised clinical protocol involving periodontal and endodontic treatments were included. Clinical parameters were measured, and the EPL grade was classified according to the 2017 World Workshop criteria. Based on the radiographic characteristics, lesions were categorised as I‐shaped (unilateral intrabony defect without apparent apical radiolucency), J‐shaped (unilateral intrabony defect with apical radiolucency) and U‐shaped (bilateral intrabony defects with apical radiolucency). Survival‐time analysis was performed. Results Of the 187 teeth included, 117 survived over the mean observation period of 3.1 ± 2.1 years (maximum, 8.4 years). The estimated 1‐ and 5‐year tooth survival rates were 83.8% and 58.9%, respectively. Multivariate analysis identified age, EPL grade, probing depth (PD), periapical index, bone loss and I‐J‐U subclassification as significant prognostic factors for tooth survival. The I‐J‐U subclassification was significantly associated with tooth survival, suggesting its potential value in prognostic assessment. Conclusion This retrospective cohort study identified age, EPL grade, PD and radiographic shape of bone loss as predicting factors for tooth survival in teeth with EPLs.
Kimura et al. (Tue,) studied this question.