Aim: The aim of this study was to evaluate the status of occlusal surfaces of first permanent molars in 6- to 8-year-old children using the Caries Assessment Spectrum and Treatment (CAST) index and to assess how it correlates with DMF in the surveyed population.
Materials and methods: A total of 1931 occlusal surfaces of first permanent molars in 6-8-year-old children from Bialystok District, Poland, were assessed using the DMF and the CAST indices. The prevalence and experience of different caries stages were evaluated. Data were statistically analysed with the Kruskal-Wallis test, the Dwass-Steele-Critchow-Fligner post-hoc test and the cross-tabulation. The intra-examiner reliability was evaluated. Results Caries prevalence on occlusal surfaces of the first permanent molars measured by DMF was 13.3% and by CAST -37.6%. The mean DMF was 0.33 and the mean D -0.07. For CAST, the mean values of early (codes 3-4) and advanced caries stages (codes 5-6) were 0.55 and 0.05, respectively. The DMF index statistically significantly increased with age. In the whole population the mean number of filled teeth was higher than the decayed ones. With reference to the CAST index, children showed increase in enamel lesions with age. The intra-examiner reliability was 0.94 for DMF and 0.88 for CAST. Conclusion The surveyed subjects showed a low prevalence of dental caries measured with DMF and a moderate prevalence when the CAST was used. The CAST index is a promising tool for epidemiological studies on caries. It provides more information on the disease prevalence, experience and severity compared to the DMF index.