Frequency of daily tooth brushing and subsequent cardiovascular events

OBJECTIVE: Although previous studies have shown an inverse association between the frequency of daily tooth brushing and cardiovascular risk factors, research on cardiovascular events is limited. This study aimed to evaluate the association between the frequency of daily tooth brushing and subsequent cardiovascular events. METHODS AND RESULTS: A retrospective longitudinal study was conducted at a hospital in Tokyo, Japan. We included all participants who underwent health check-ups from 2005 to 2011 and followed up to 2018. Our outcomes were the development of cardiovascular events. Outcomes were compared by the frequency of daily tooth brushing with a generalized estimating equation, adjusting for potential confounders. A total of 71 221 participants were included. The mean age was 45.6 years and 50.3% were male. During a median follow-up of 2061 (interquartile range: 933-3311) days, 1905 participants developed cardiovascular events. The adjusted odds ratios (ORs) of cardiovascular events increased in a dose-dependent manner as the frequency of tooth brushing decreased. Even those who brushed their teeth once in a day had a higher adjusted OR of stroke (1.22; 95% confidence interval, 1.01-1.48) than did those who brushed after every meal. CONCLUSIONS: Frequent tooth brushing was inversely associated with subsequent cardiovascular events in a dose-dependent manner. Even brushing one's teeth once a day may be related to an increased likelihood of stroke than brushing one's teeth after every meal. Less frequent tooth brushing may be considered to be a marker for subsequent cardiovascular disease and coronary heart disease, rather than a risk factor.