Abstract: Objective: To observe the prognostic factors of periodontal-derived combined periodontal-endodontic lesions. Methods: A retrospective analysis was used to analyze the clinical trial data of 74 teeth with combined periodontal-endodontic lesions treated by the same physician in the Periodontology Department of Nanjing Stomatological Hospital in China from 2013 to 2015. The teeth were divided into two groups according to tooth retention. Age, sex, follow-up time, periodontal clinical examination index at baseline and 5-year follow-up, and other factors affecting prognosis were analyzed. The Kaplan-Meier test and log-rank method were used to evaluate the survival rate of teeth. Results: The overall survival rate of 74 teeth was 44.1%, and the 5-year survival rate was 52.5%. There was no significant difference in survival rates between gender, dental arch, and tooth position. There were significant differences between two groups in the follow-up times, mean probing depth (PD), mean attachment loss (AL), and maximum AL at baseline. The tooth survival rate between cases with average PD≤5 mm and PD>5 mm, and cases with average AL≤6 mm and AL>6 mm were statistically different. There were statistical differences regarding teeth mobility (TM), sulcus bleeding index (SBI), average PD value, maximum PD value, and maximum AL value at 5-year follow-up compared to the baseline. Conclusion: For periodontal-derived combined periodontal-endodontic lesions, the short-term effect is predictable, but the long-term prognosis is poor. The average damage of periodontal supporting tissues and patient compliance are important factors that affect the survival time of teeth.

Key words: combined periodontal-endodontic disease, periodontal treatment, prognosis, survival rate