Trends and determinants of dental care utilization among Korean adults: a 10-year analysis of the Korea National Health and Nutrition Examination

Objectives: This study examined trends in dental care utilization among Korean adults over the past decade and investigated differences in sociodemographic and behavioral factors, with a particular focus on income level.Methods: Data from the 6th (2013-2015) to 9th (2022-2023) waves of the Korea National Health and Nutrition Examination Survey were analyzed for adults aged 19 years.Independent variables included sex, age, education, income, residential area, hypertension, diabetes, high-risk drinking, smoking, and toothbrushing frequency (2 times per day).Complex sample frequency analysis and chi-square tests were performed to examine differences in dental care utilization, and complex sample logistic regression was employed to identify factors associated with utilization in Wave 9, after adjusting for all covariates.Results: Dental care utilization increased from 48.8% in 2013-2015 to 60.7% in 2022-2023.Utilization improved across most subgroups; however, income-related disparities persisted.In Wave 9, higher income levels were associated with a greater likelihood of utilization compared with level I: level II (odds ratio [OR]=1.20,95% confidence interval [CI]=1.04-1.40),level III (OR=1.22,95% CI=1.05-1.43),level IV (OR=1.31,95% CI=1.13-1.52),and level V (OR=1.67,95% CI=1.44-1.94).These associations remained significant after adjustment (Nagelkerke's R 2 =0.032).Conclusions: Dental-care utilization among Korean adults has increased over the past decade; however, disparities related to income level persist.Policies aimed at improving access and reducing socioeconomic barriers are needed to promote equitable utilization of dental services in Korea.