Trends in Pre-bedtime Toothbrushing Rate and Associated Factors among Korean Adults: A Time-series Analysis Using KNHANES 2010–2023

Objective: This study aimed to investigate longitudinal trends and sociodemographic determinants of pre-bedtime toothbrushing practices among Korean adults aged 19 years and older between 2010 and 2023. Methods: Data were obtained from the 5th(2010–2012) to the 9th(2022–2023) waves of the Korea National Health and Nutrition Examination Survey (KNHANES). Temporal trends were assessed across survey cycles, and complex sample logistic regression was employed using the most recent data to examine the association between age, education attainment, and pre-bedtime toothbrushing practice. Results: While the overall prevalence of pre-bedtime toothbrushing increased over the study period, disparities based on age and education level persisted and, in some cases, widened. Notably, older adults and individuals with lower educational attainment consistently demonstrated significantly lower rates and odds of practicing pre-bedtime toothbrushing. Conclusions: Pre-bedtime toothbrushing, a fundamental practices for maintaining oral health, remains unevenly practiced across demographic groups. These findings underscore the need for targeted behavioral interventions and supportive policy frameworks aimed at reducing oral health disparities among socioeconomically disadvantaged populations, particularly older adults and those with limited educational backgrounds.