Background: Many background variables, such as socioeconomic status (SES), may be measured at the level of the individual or using some ecological indicators. Objectives: This study aimed to examine, in 5- and 10-year-olds in Clermont-Ferrand, the relationship between household SES indicators, SES measured as an area-based ecological variable and dental status. Methods: All 5- and 10-year-olds attending public schools in deprived and semi-deprived zones (n = 15) and six other randomly selected schools in Clermont-Ferrand were invited to participate. All children were examined clinically. On a questionnaire, parents provided sociodemographic information. Results: Of the children invited, 84% (880 children) were examined. Mean dft of 5-year-olds was 0.93 (SD 2.27); 26.5% had at least one tooth affected. The caries experience (DMFT) of 10-year-olds was 0.85 (SD 1.14) and 37.2% had permanent tooth caries experience. Caries experience varied significantly with school deprivation status: the greater the deprivation score, the more likely was poor dental health. Country of birth, parents' employment status, family size and health insurance type were significantly related to dental status. Logistic analyses estimated the importance of SES and ecological variables; deprivation influenced dental status in 5-year-olds even when household SES indicators were considered. In 10-year-olds, caries experience was influenced by household SES, immigrant background, father's employment and family size. Conclusion: The use of school deprivation as an ecological measure status was useful for identyfing population subgroups with different levels of oral health, particularly in young children. This indicator of social deprivation could be used for targeting preventive programmes to high caries risk communities defined geographically.
