Association between tooth brushing habits and incident disability in community-dwelling older adults: a prospective cohort study

Background: Japan is experiencing a rapid demographic shift toward a super-aged society, making the extension of healthy life expectancy a national priority. Oral self-care, particularly tooth brushing habits, may play a critical role in preventing functional decline among older adults, yet evidence in this population remains limited. This study aimed to examine the association between specific tooth brushing behaviors—frequency, timing (especially before bedtime), and use of interdental cleaning tools—and incident disability among community-dwelling older adults in Japan.