[How does the rate of participation in epidemiologic research affect oral health data?]

The question to which extent an unintended selection is linked with incorrect estimations of oral disease indicators by the readiness of subjects to participate is looked into within the framework of an epidemiological study. 896 primarily cooperative subjects and 70 originally noncooperative subjects aged from 25 to 64 years were examined. According to statistics, non-cooperative subjects were found to have more caries-infected teeth and less teeth filled. Generally, a smaller degree of dental care could be detected in these subjects, which should cause a critical discussion of the hitherto published parameters of oral diseases.