Objective To investigate dental caries in 3-year-old children in Jing′an District of Shanghai and analyze the influence of oral cleaning behavior on caries in children.

Methods Six hundread 3-year-old children from 12 kindergartens in Jing′an District, Shanghai were randomly selected by cluster sampling method for oral examination, and a self-administered questionnaire survey on children′s oral cleaning behavior was completed by parents.SPSS 22.0 software package was used for statistical analysis.

Results Among the 600 children, the prevalence of dental caries was 42.50%, and the average dmft index was 1.76±2.92.Children who did not brush their teeth had a statistically significant increase in rate of dental caries(χ²=29.995, P < 0.001).Children who brushed their teeth for more than three minutes each time had a statistically significant lower rate of caries(χ²=3.918, P=0.048).Children whose parents helped their children brush their teeth every day had a lower rate of caries than those who brushed teeth by themselves, and the difference was statistically significant (χ²=8.718, P=0.013).Logistic regression analysis showed that age of beginning brushing teeth, times of brushing teeth per day and length of brushing teeth per time were all influence factors for caries in children (P < 0.05).

Conclusion For the prevention and control of dental caries in 3-year-old, proper oral cleaning behavior is very important.We should make parents as a priority group for doing oral hygiene in children.Schools should strengthen oral health education for parents.Medical institutions should guide and monitor the effectiveness of oral hygiene in children.It is important to reduce the rate of dental caries in preschool children from three aspects:family, school and medical institutions.