The aim of the study was determination of the microsolubility of permanent teeth enamel by the CRT test depending on the degree of caries intensity. Indirectly, it was tried to obtain an answer to the question whether the test could be used for the assessment of caries susceptibility. Forty-six patients of either sex aged 18 to 30 years were studied. The state of caries was determined by the CDF index. Enamel solubility was determined by the CRT test on the surface of permanent teeth--incisors, canine teeth, second premolars and first molars. In all, 460 surface were examined. After the test 75% fluoride paste was rubbed into the surface. The obtained results of the CRT test were collected in two groups depending on the increasing value of the CDF index. The statistical analysis was done using the correlation coefficient and Student's t test. No statistically significant correlation was found between enamel microsolubility expressed by the CRT test and the degree of caries intensity determined by the CDF index. The results obtained by this method could not confirm the view that the CRT test is useful for determination of enamel susceptibility to caries development.