Association Between Periodontal Status and Oral Health-Related Quality of Life: A Cross-Sectional Study

Background and Objectives: Periodontal diseases are highly prevalent worldwide and have been associated with impaired oral health-related quality of life (OHRQoL). However, the strength and direction of this association remain inconsistent, particularly when sociodemographic and behavioural factors are considered. The aim of this study was to evaluate the independent association between periodontal status and OHRQoL in Bulgarian adults attending a university dental clinic, while accounting for sociodemographic factors and sleep quality, which was included as a clinically relevant behavioural determinant of oral health-related quality of life. Materials and Methods: This cross-sectional study included 504 adult participants (≥18 years) who underwent comprehensive periodontal examination and completed validated questionnaires. OHRQoL was assessed using the culturally adapted Bulgarian version of the Oral Health Impact Profile (OHIP-14), and sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). Due to the skewed distribution of OHIP-14 scores, the outcome was dichotomized at the sample median. Multivariable logistic regression analysis was performed to assess independent associations, adjusting for age, sex, education, financial status, place of residence, and sleep quality. Results: Periodontal status, sex, and sleep quality were independently associated with impaired OHRQoL. Females demonstrated lower odds of impaired OHRQoL compared to males (OR = 0.636; 95% CI: 0.428–0.924; p = 0.025). Poor sleep quality was associated with increased odds of impaired OHRQoL (OR = 1.554; 95% CI: 1.041–2.321; p = 0.031). Periodontitis was significantly associated with impaired OHRQoL (OR = 3.526; 95% CI: 2.073–5.998; p < 0.001), reflecting a complex relationship between clinical periodontal status and subjective health perception. Conclusions: OHRQoL is influenced by a multifactorial framework integrating periodontal status, behavioural factors, and sociodemographic characteristics. These findings highlight the importance of incorporating patient-reported outcomes into periodontal assessment and support a biopsychosocial approach to oral health research.