Determining the impact of risk factors is fundamental in developing efficient methods for preventing the occurrence of caries both in children and adults. Aim. To evaluate the relationship between the presence of caries in milk teeth and the development of caries in the first permanent molar teeth of 7 year old children. Material and methods. The study was performed on the teeth of 2138 children, including 1033 girls and 1105 boys, aged 7 and living in the city of Poznań. In the clinical study the presence and intensity of caries in milk teeth was evaluated and then compared with the caries that appeared in the first molar permanent teeth. On the basis of the data collected, the frequency and intensity (dmft, DMFT(6)) of caries in milk teeth and later in the first permanent molar teeth were calculated. To detect a correlation between dmft and DMFT(6) a statistical analysis of the results was performed and the Pearson coefficient of linear correlation was calculated. Results. The frequency of caries in milk teeth in the studied population was 81.20%, while in the first molar teeth it was 9.21%. The average puw‑z for milk teeth was 3.89 ± 3.09, while the average DMFT(6) for permanent molars was 0.14 ± 0.52. A positive correlation was found between the presence of caries in milk teeth and the first permanent molars. Conclusions. The presence of caries in milk teeth (dmft) is a factor conducive to its appearance in the first permanent molars DMFT(6), this correlation is statistically significant. The number of milk teeth with caries (dmft) is positively correlated with the level of risk of this disease in permanent teeth.

Key words: intensity and frequency of caries, 7-year old children, the first permanent molars.