RESUMO
PORPOSE: To establish a prospective cohort of kindergarten children and longitudinally study the causes of early childhood caries. METHODS: Cluster random sampling was used to select a kindergarten in the urban and suburban areas of Pudong New District of Shanghai, a total of 240 small-class children joined the study. Chi-square test, analysis of variance, binomial logistic regression model and general linear regression model was used to analyze caries of the cohort children at baseline and 1 year after follow-up with SPSS 21.0 software package. RESULTS: In the first two years of this cohort study, the follow-up rate was 88.3%, the caries rate in the first year of baseline and follow-up were 58.3% and 69.8%, and the mean dmft values were 3.1±4.2 and 4.5±4.9, respectively. 56.1% of children had new caries. Logistic regression results showed that children who lived in the suburbs (P=0.010) and ate candy more frequently (P=0.036) had higher rates of new caries. The results of general linear regression equation showed that children in the suburbs (P<0.001), those who did not use fluoridated toothpaste (P=0.003) and those who ate candy more frequently (P=0.002) had higher new mean dmft values. CONCLUSIONS: Living in the suburbs, not using fluoride toothpaste and eating candy more frequently are important risk factors for new caries in preschool children in Pudong New District of Shanghai.