Dental Visits and Changes in Oral Health over Time among Australian Adults

OBJECTIVE: To evaluate the causal relationship between dental visiting patterns and changes in oral health outcomes among Australian adults aged 18 and older. METHODS: Longitudinal analyses were conducted using data from the Australian National Study of Adult Oral Health, collected in 2004 to 2006 and 2017 to 2018 (n = 1,707). Routine attendance (RA) was defined as dental checkups within the past 12 months, primarily for preventive reasons. Three exposure groups were identified: those with (1) routine visits at both times, (2) one routine visit, and (3) nonroutine visits at both times. Three oral health outcomes were evaluated: changes in self-rated oral health, self-rated toothache, and pathology-related tooth loss. Confounders included sex and country of birth as baseline variables. Household income, age, education, employment status, general health rating, smoking status, and dental visit sites were treated as time-varying confounders. Marginal structural models with inverse-probability weighting were used to evaluate causal effects. Propensity scores were calculated using logistic regression, incorporating all confounders listed above. RESULTS: Descriptive analysis indicated that individuals with two-time RA had better oral health than those with one-time or no RA did. After accounting for selected confounders using propensity score weighting, compared to two-time RA, one-time RA had higher probabilities of poor self-rated dental health (risk ratio RR (95% confidence interval CI): 2.07 1.32, 3.23) and more frequent self-rated toothache (RR 95% CI: 1.69 1.31, 2.17). No RA had even higher risks (RR 95% CI: 3.74 2.46, 5.69 for poor dental health; RR 95% CI: 1.76 1.37, 2.26 for toothache). The RR demonstrated more pathology-related tooth loss (RR 95% CI: 1.21 0.96, 1.54) among the one-time or no RA than the two-time RA. CONCLUSION: This study demonstrated that routine dental visits improved self-rated oral health, reduced frequency of toothache, and were associated with less pathology-related tooth loss.Knowledge Transfer Statement:These findings highlight the importance of routine dental checkups in maintaining long-term oral health. Clinicians and policymakers can use this evidence to support preventive care strategies and promote regular dental attendance, which may lead to improved self-rated oral health, reduced toothache, and lower risk of tooth loss among adults.