Unveiling the true burden of endodontic adverse events in academic settings: A five-year multivariate risk analysis.

BACKGROUND: Adverse events in endodontics remain an underexplored aspect of patient safety, with limited research employing robust multivariate methodologies to identify contributing risk factors. MATERIAL AND METHODS: Retrospective cohort study conducted in the postgraduate endodontics clinics at the University of Cartagena. All included records required a minimum six-month post-treatment follow-up, tracking the same patients from treatment to outcome, which supports the cohort design classification. From a total of 2,852 clinical records, a representative sample of 384 was selected. Variables analyzed included patient demographics, treatment type, case complexity, and provider training level. Statistical analyses comprised descriptive statistics, chi-square testing, stepwise multivariate logistic regression, Kaplan-Meier survival curves, Cox regression, and model validation through bootstrap resampling and cross-validation. RESULTS: Among the 384 records reviewed, the incidence of adverse events was 15.1% (95%CI: 11.8-19.0%; n=58). The most frequent event was instrument fracture (62.1%, n=36), followed by over-obturation (20.7%, n = 12) and perforation (17.2%, n = 10). Multivariate analysis identified four independent risk factors: third-semester versus first-semester students (OR = 2.84; 95%CI: 1.52-5.31; p = 0.001), patient age 30-39 versus <30 years (OR = 2.12; 95%CI: 1.18-3.81; p = 0.012), retreatment versus initial treatment (OR = 3.67; 95%CI: 1.94-6.95; p < 0.001), and molar versus anterior teeth (OR = 2.45; 95%CI: 1.28-4.69; p = 0.007). The predictive model demonstrated strong discriminatory power (C-statistic = 0.782; 95%CI: 0.731-0.833) and good calibration (Hosmer-Lemeshow p = 0.622). CONCLUSIONS: The true incidence of adverse events in academic endodontics is notably higher than previously reported. The identified risk factors support the implementation of targeted preventive strategies and inform educational supervision and patient safety protocols.