This study examines the association between denture use and all-cause mortality risk among Chinese edentulous elderly, using data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS, 2008–2014 waves). A cohort of 8444 adults aged \(\ge 60\) with complete tooth loss was analyzed, with denture use recorded as a binary variable (yes/no) and mortality verified via follow-up linkages. Missing data were handled via multiple imputation (MICE), and propensity score matching (PSM) balanced covariates between denture users and non-users. Kaplan-Meier survival analysis demonstrated significantly improved survival probabilities among denture users compared to non-users (log-rank p = 0.0033). Multivariate Cox proportional hazards models, after full adjustment for potential confounders, consistently revealed that denture non-users faced a 15.8% higher mortality risk (HR = 1.158, 95% CI 1.082–1.239, P < 0.001). Mediation analyses elucidated potential pathways, identifying BMI as a significant partial mediator (indirect effect = − 0.010, P < 0.001) in the denture-mortality relationship. In contrast, neither dietary diversity (DDS: p = 0.105) nor daily staple food intake (DSFA: p = 0.190) demonstrated significant mediating effects. The robustness of these findings was confirmed through comprehensive sensitivity analyses, including complete-case analysis and evaluation of pre-propensity score matched cohorts, with all approaches yielding consistent results. This study provides robust evidence that denture use is significantly associated with reduced all-cause mortality among edentulous elderly adults, with BMI serving as a key mediating factor in this protective relationship.
