Caries Prevalence In 9 To 12 Year Old Children From Czernobyl Lemke, A. Schult, I. Laàβson, U. Platzer* (Universitäts-Krankenhaus Eppendorf, Klinik Und Poliklinik Für ZMK-Krankheiten, Abteilung Zahnerhaltung Und Parodontologie, Martinistr. 52, 20246 Hamburg, Germany) The aim of the present study was to determine caries prevalence in children within a medically and dentaly sub-standard care infrastructure. Parallel investigation focused on potential effects of radioactive exposure on hard tooth substance in this geographic area.   Notable events in the medical histories of the 24 girls and boys aged 9 to 12 were documented; the children then underwent a detailed oral inspection as a randomized group. Tooth-brushing behaviour was also reported and a statistical evaluation of caries prevalence was carried out.   The histories revealed a compromised physical constitution in terms of concentration and physiological performance in these children.   Statistical evaluation determined that, within a framework of a relatively low socio-economic status, caries prevalence in all of the children was relatively high compared with European study data with DMF-T averaging 4.71 and DMF-S at 6.17. Epidemiological studies involving 2667 school children in Bavaria showed a DMF-T in 9-year-olds of 0.35 and in 12-year-olds of 1.07 (Reich et al. 1999); collective, group and individual prophylaxis in a Swiss study resulted in caries reduction to a DMF-S of 1.3 (Büttner et al. 1997).   There was considerable discrepancy between the DT value of 3.17 and the FT value of 1.86; also, a large percentage of the cavities in the molars and pre-molars had been treated with insufficient composite fillings.   The highly disciplined behaviour of the children during the therapeutic procedures - despite a fear of dental treatment in some cases as well as the language barrier - was notable.