The authors decide to evaluate the results of measuring by laser fluorescence apparatus DIAGNOdent (KaVo) in the in vitro experiment. 100 occlusal surfaces of extracted lower and upper third molars, which communicated with oral cavity before extractions, were examined with using laser fluorescence apparatus and were marked for the place of the highest reading. The teeth were cut longways in the place of the highest reading. Caries detector by Fussayama was applied on the cut surfaces. They made digital photos with using a tripod of all teeth cut surfaces and measured coloured caries depths with using computer program Adobe Photoshop. Statistical examination was possible to confirm or exclude a corellation between measure readings. Statistical examination did not confirm the hypothesis that the higher number acquired by DIAGNOdent meant the bigger dentinal caries depth. Sensitivity for dentinal caries was 80.7%, specifity 35.6%.

        Key words: laser fluorescence – DIAGNOdent – caries detector – tooth decay