Association between Insufficient Sleep and Dental Caries among Preschoolers in Japan: A Cross-Sectional Multicentre Study

Recently, sleeping status has attracted attention for its relationship with oral health. In the present study, we have investigated the association between early childhood caries and sleeping status. A multicentre observational cross-sectional study was conducted among 332 preschoolers (aged 3–6 years) and their parents in Chitose, Japan. Dental caries and sleeping status were assessed in the children and the sleep quality and health literacy of the parents were also assessed. Univariate and multivariate regression analyses were used in order to investigate the effect of the sleeping status of the parents and their children on dental caries. Among the children, the prevalence of dental caries experience was 12.7%. The children without caries slept significantly longer and their parents had a better Pittsburgh Sleep Quality Index (PSQI) score than those with caries experience. The sleeping status and the numbers of caries in the children were significantly correlated. Health literacy was better in those without caries experience. Parents’ PSQI was significantly positively correlated with the numbers of caries in the children (r = 0.19, p = 0.0004). The children’s sleep durations, screen time, and parental smoking status were independently associated with early childhood caries. Poor sleeping status of children and their parents is related to dental caries among preschoolers.