[Comparative analysis of two methods of the CRT test in children with high and low DMF value].

The study of enamel microdemineralization by the CRT test was done in 40 children of either sex aged 12 years with low and high DMF index value. Two methods of carrying out the CRT test were analysed: the method of one drop of HCl 1 n placed on a filter paper disc put directly onto enamel surface (CRT I) and the method of soaking the paper disc with 1 n HCl for 30 seconds with later placing of the disc on enamel surface (CRT II). A difference was found between CRT I and CRT II in the time of enamel microdemineralization. The enamel microdemineralization time by the CRT I was significantly longer than with the CRT II method, in the whole group of children and in groups with low and high DMF value. A statistically significant correlation was demonstrated also between the mean DMF value in the tested children and the mean time of enamel demineralization on the one hand, and the method of CRT performing, on the other hand. Of the analysed methods of CRT performing the method with 1 n HCl drooping onto the paper disc on a slide (CRT II) seems to be superior in view of its simplicity and safety.