Social differences in tooth decay occurrence in a sample of children aged 3 to 5 in north-east Italy.

To correlate the occurrence of tooth decay with a social class indicator (occupational level) and the immigrant status in a sample of pre-school children in Veneto region. Cross-sectional survey. Twenty nursery schools in the area of Health District n.15. A total of 1,410 children aged 3 to 5 years old visited between September 2005-May 2006. Occurrence of dental caries into dentine threshold was made visually and confirmed with a probe when necessary by two calibrated examiners. Information on immigrant status and occupational level of parents was obtained by a questionnaire. Children were categorized as immigrant or non-immigrant on the basis of their mother's country of origin. Means and standard deviation were calculated for continuous variables; for categorical variables the results were provided as proportions. Comparisons between groups were made using Pearson chi-square test. The association between caries occurrence and the independent variables gender, age, immigrant status and family social class was evaluated by means of a logistic regression model. Caries occurrence was higher among children from lower social class families (1.7 +/- 3.2) than among children from higher social class (0.8 +/- 2.1). The prevalence of dental caries in immigrant preschool children was significantly higher than in indigenous ones (15% vs 40%; p = 0.000) while the severity in immigrants was almost 4 times higher (2.2 +/- 3.6 vs 0.6 +/- 1.8). Our data on preschoolers confirm the worldwide literature shared statement that social class as well as immigration status are determinants of oral health.