BackgroundDental attendance is important for the prevention, diagnosis, and treatment of oral diseases. In this study, we aimed to assess the extent of the association between dental visits, inadequate oral health, and multimorbidity (MM), and whether this association differs by age and sex.MethodsWe conducted a cross-sectional analysis of the first follow-up wave (2018) of the Canadian Longitudinal Study on Aging (CLSA). Poor self-reported oral health (SROH), oral health problems, and edentulism were used to indicate inadequate oral health. MM was defined as having 2 or more chronic conditions out of cancer, cardiovascular diseases, chronic respiratory diseases, diabetes, and mental illnesses. Dental visiting was determined as the number of visits to a dental professional within the past 12 months. Covariates included socioeconomic, behavioural factors, and the availability of dental insurance. We constructed multivariable Poisson and logistic regression models with interactions terms and estimated the relative excess risk due to interaction prevalence ratio (RERIPR) to assess the effect measure modification of age and sex on the associations of interest. We conducted sensitivity analyses and estimated E-values for unmeasured confounding.ResultsIn this sample (n = 44,815), dental visiting was inversely associated with inadequate oral health and MM in adjusted models, reducing the odds/prevalence of poor SROH (OR 0.41, 95% CI 0.34, 0.51), oral health problems (PR 0.89, 95% CI 0.79, 0.94), edentulism (OR 0.10, 95% CI 0.06, 0.15), and MM (PR 0.86, 95% CI 0.79, 0.92). These associations were stronger in older age and females.ConclusionDental visiting may contribute to better oral health and reduced chronic diseases in the middle-aged and older population. Our findings suggest the need for age and sex-specific targeted interventions to optimize oral and overall health.