A longitudinal study of self-report tooth loss impacting functional status among Chinese older adults: Moderated mediation of social relationships and psychological resilience

Objectives: This study aimed to discern the longitudinal association between tooth loss and subsequent functional status, specifically investigating the moderated mediation effects of social relationships and psychological resilience.Methods: Data from the 2011, 2014, and 2018 waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) were analyzed, we included 2834 older adults aged 65 and over in the study. The longitudinal relationship between tooth loss and functional status was analyzed using the generalized estimating equation. Hayes' PROCESS macro for SPSS was utilized to study the mediating and moderating effects.Results: In the fully adjusted model, the number of natural teeth at T1 was positively associated with instrumental activities of daily living (IADL) score at T3, but not activities of daily living (ADL) score. Compared with 20+ teeth, participants with complete tooth loss at T1 had a higher risk of developing ADL and IADL disability. Participants with 1-9 teeth at T1 had a 38 % risk of developing IADL disability at T3 (OR = 1.38, 95 % CI = 1.07-1.76, p = 0.012). Social relationships mediated the association between tooth loss and IADL only among participants whose psychological resilience was average (B = 0.0006, 95 % CI = 0.0001-0.0014) or high (B = 0.0013, 95 % CI = 0.0003-0.0026).Conclusion: Psychological resilience moderated the mediating effects of social relationships on the association between tooth loss and functional ability. Clinical significance: This longitudinal study contributes to elucidating parts of social-psychological mechanisms underlying tooth loss and functional disability. It suggests that by cultivating positive social relationships and enhancing psychological resilience, the adverse impacts of tooth loss on functional disability may be mitigated.