Periodontal Disease and Endo-Periodontal Lesion Subtypes: A Retrospective Study

Background/Objectives: Endo-periodontal lesions (EPLs) represent complex pathological entities involving both periodontal and pulpal tissues, often implying diagnostic and therapeutic challenges. Limited evidence exists regarding the relationship between periodontal disease staging and grading and EPL subtype. The aim is to evaluate the clinical and statistical distribution of endo-periodontal lesions and investigate their association with periodontal stage and grade according to the European Federation of Periodontology (EFP) classification. Methods: An observational retrospective study was conducted in the Department of Periodontology, Faculty of Dental Medicine, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania. Among 884 examined patients, 31 of them were diagnosed with EPLs and included in the analysis. Demographic variables, systemic conditions, affected tooth type, EFP stage and grade, and EPL type according to the Foce classification were recorded. Statistical analysis included Fisher’s exact test and univariable and multivariable binomial logistic regression models. Results: The mean age of the patients was 53.55 ± 9.42 years, with a nearly equal gender distribution. Most patients presented Stage III periodontitis (54.8%), Grade B periodontitis (71%), and EPL 3 (58.1%). Pluriradicular teeth were the most frequently affected (64.5%). The only statistically significant association identified was between EFP grading and EPL classification (p = 0.001). Grade B patients were significantly more likely to present EPL 3 than Grade C patients. Logistic regression analysis demonstrated that Grade B was a strong predictor of EPL 3 both in the univariable model (OR = 27.2; 95% CI: 2.712–272.828) and after adjustment for age and gender (OR = 32.676; 95% CI: 2.832–376.984). Neither age nor gender showed a significant association with EPL 3 occurrence. Conclusions: EPL 3 was the predominant lesion subtype in the study. EFP grading was significantly associated with EPL distribution, with Grade B emerging as an independent predictor of EPL 3. These findings suggest that periodontal disease progression may play a key role in the development and characterization of combined endo-periodontal lesions and highlight the importance of integrated periodontal–endodontic assessment in clinical practice.