AN IN-VITRO EVALUATION OF FLUORESCEIN PENETRATION INTO NATURAL ROOT SURFACE CARIOUS LESIONS

In order to develop a method for detection and quantification of initi al root surface carious lesions, the use of fluorescein sodium as a fl uorescent dye is evaluated. The penetration depth of fluorescein sodiu m into human roots containing natural carious lesions was measured on approximately 130-mum-thick slices, cut in a direction perpendicular t o the pulp. This depth was compared to the lesion depth that was measu red on the same slice with transversal microradiography. The results i ndicate that fluorescein sodium in water penetrates into demineralized layers of root dentine even if a surface layer with a high mineral co ntent is present. The penetation depth is about 1.1 times the microrad iographically determined lesion depth.