Role of social class in caries occurrence in 12 year olds in Turin, Italy

Background: The objective of the study was to evaluate the social distribution of dental caries and its determinants in the province of Turin, an area of 2,300,000 inhabitants in the north of Italy. Methods: A cross- sectional study was carried out among a representative school-based sample of 11-12 year olds. A total of 734 (84.0% of the starting sample) students were involved. Two questionnaires were submitted (to students and parents) and the children received a dental examination. Dietary and hygiene indicators were calculated and the DMFT index (the number of decayed, missing and filled teeth) was measured using methods recommended by the World Health Organisation (WHO). The education level of the head of family was used as a proxy of social class indicator. Univariate and multivariate analyses were applied to obtain results. Results: Students from disadvantaged families showed: i) a higher tendency to belong to the higher risk group for oral hygiene (RR primary school/university = 2.78); ii) a lower use of dental prevention (RR=0.40 for use of fluoride tablets and RR=0.43 for local applications of fluoride) and iii) a higher consumption of sucrose-sweetened foods (RR=1.17%, ns) when compared with children of graduate parents. The DMFT index was more than double among children whose parents only had a primary school education, compared with those of graduate parents (3.2 versus 1.5). In addition, the percentage of caries-free children increased from 16.4 to 59.1% from the lowest to the highest social group. Conclusions: Large social differences are found in caries experience and in determinants of dental decay. Nevertheless, determinants of caries occurrence seem to explain only a small fraction of inequalities.