Effect of sleep on development of early childhood caries: a systematic review

PURPOSE: To investigate the impact of sleep on the development of early childhood caries (ECC). METHODS: Seven electronic databases and grey literature were searched with various keyword combinations. Two reviewers independently selected studies, extracted data, and assessed the risk of bias using the Newcastle–Ottawa Scale. The studies were included if they evaluated the impact of sleep parameters on the caries experience or severity of ECC in children under 6 years of age. RESULTS: Four cross-sectional studies and two longitudinal studies were included. Children who had irregular bedtimes had a 66–71% higher chance of developing ECC. Children who slept after 11 pm might have a 74–85% higher chance of developing ECC. Children who slept less than 8 h during the night had a 30% increased risk of caries than children who slept more than 11 h. CONCLUSION: Irregular or late bedtime and fewer sleeping hours could be an independent risk factor for ECC. The risk of ECC might be related inversely in a dose–response manner to the number of sleep hours.