[From epidemiology to social epidemiology in dentistry. The example of caries]

Today, we know the caries aetiology and prevention rather well. We also know that caries-related levels of dental health are inequitably distributed among social classes: on the average, disadvantaged people experience higher DMFS then privileged people. This difference can be explained by a differential access to health care, which can be shown by the study of components of the DMFS index: proportion of filled surfaces (F/DMFS), proportion of missing surfaces (M/DMFS), and proportion of recurrent caries (secondary caries/filled surfaces). Though we are able to describe the social distribution of levels of dental care, we cannot "explain" the differences we observe. The explanation of those differences defines the field of social epidemiology. This consists in determining the social aetiology of diseases, starting from social determinants of attitudes and behaviors influencing health.