Patient-reported outcomes following nonsurgical treatment of endo-perio lesions: oral health–related quality of life and sleep quality in a retrospective observational study

Endo-perio lesions (EPLs), arising from the close anatomical and pathophysiological relationship between pulpal and periodontal tissues, may markedly impair oral health–related quality of life (OHRQoL) and sleep quality. Although the individual effects of endodontic and periodontal diseases on patient-reported outcomes have been widely documented, evidence evaluating their combined impact following nonsurgical therapy, particularly across lesion types and severity stages, remains limited. This single-center retrospective observational study included 97 systemically healthy, non-smoking adults allocated to three diagnostic groups: periodontitis (P), non-periodontitis EPL (N-EPL), and periodontitis-associated EPL (P-EPL). Disease-severity subgroups were defined according to the 2017 World Workshop classification. All patients underwent standardized nonsurgical endodontic and/or periodontal treatment protocols. OHRQoL and sleep quality were assessed at baseline and at least six months post-treatment using the Oral Health Impact Profile-14 (OHIP-14) and the Pittsburgh Sleep Quality Index (PSQI). The primary outcomes were defined as the changes (Δ = T₀–T₁) in total OHIP-14 and total PSQI scores. The main comparison of interest was the difference in these change scores among diagnostic groups and disease severity stages. Treatment-related changes (Δ = T₀–T₁) were compared among groups and severity stages using appropriate non-parametric and post-hoc analyses. At baseline, OHRQoL and sleep quality were significantly poorer in the P and P-EPL groups than in the N-EPL group. Following treatment, significant improvements were observed in most OHIP-14 domains and global PSQI scores across all groups, with the largest observed change scores occurring in patients with more advanced disease severity and higher baseline burden. Intergroup comparisons revealed greater ΔOHIP and ΔPSQI scores in the P and P-EPL cohorts than in the N-EPL cohort. These patterns remained generally consistent after additional analyses, although the strength of some associations was attenuated. Several PSQI components related to sleep medication use and daytime dysfunction showed limited change. Nonsurgical endodontic and periodontal therapy was associated with improvements in both OHRQoL and sleep quality across all groups, with greater observed changes in patients with higher baseline disease burden. These findings highlight the importance of incorporating patient-reported outcome measures into routine endo-perio care and may inform multidisciplinary, patient-centered management strategies. Not applicable. This retrospective observational study did not require prospective registration.