Role of social capital on edentulism, social participation and cognition

OBJECTIVES: The role of social factors in the relationship between tooth loss and cognitive function remains underexplored. This cross-sectional study investigates whether social participation mediates the relationship between tooth loss and cognitive function, and whether contextual social capital moderates these associations among older Chinese adults. METHODS: Data from 7796 Chinese adults aged ≥65 was obtained from the 2017-18 Chinese Longitudinal Healthy Longevity Survey (CLHLS). Tooth loss was self-reported and cognitive function was measured using the Chinese version of the Mini-Mental State Examination. Social participation was assessed through engagement in activities and interactions with friends, while social capital included community trust, network size, and various support types. Mediation and moderation were analyzed using PROCESS and structural equation modeling, controlling for age, gender, residential area, occupation, education, economic status, and smoking. Sensitivity analyses were conducted to assess the impact of wearing dental prostheses. RESULTS: After covariate adjustment, social participation mediated the negative relationship between tooth loss and cognitive function. Social capital influenced the association between social participation and cognition, with higher social capital potentially weakening the negative indirect relationship between tooth loss and cognitive function. For individuals without dental prostheses, social capital moderated the relationships between social participation and cognition, as well as tooth loss and cognition, but not for those with prostheses. CONCLUSIONS: Social factors appear to influence the relationship between tooth loss and cognitive function. Further longitudinal studies are needed to confirm these findings, which could inform health promotion strategies targeting the psychosocial aspects of health in edentulous older adults. CLINICAL SIGNIFICANCE: Oral health may be linked to systemic health, not just biologically, but also in the social and psychological domains. Dental professionals and policy makers should consider patients' broader social contexts when evaluating oral health, particularly among vulnerable populations such as older adults and individuals with limited social support.