Application of DIAGNOdent® as a guide for removing carious dentin with Er:YAG laser

Objectives The purpose of this study was to investigate the DIAGNOdent® values applicable as a guide for removal of outer layer of carious dentin with Er:YAG laser. Methods Carious dentin of human extracted molars was removed by bur with Caries Detector® (Group 1: red stained dentin was left, Group 2: light pink stained dentin was left) and by Er:YAG laser with DIAGNOdent® value as a guide (30>Group 3>21, 20>Group 4>11, 10>Group 5). The cavity floor dentin after removing carious dentin was examined using microradiograms, EPMA and SEM. Results The cavity floor dentin of group 1,3 showed the decreases in the degree of X-ray absorption. In group 2,4 and 5, decrease of Ca, P were not observed. The decrease of Mg was observed on the more superficial part of the cavity floor for group 3 than for group 4. Conclusions When carious dentin was removed using Er:YAG laser, the carious dentin outer layer was ideally removed with DIAGNOdent® values: 11–20. DIAGNOdent® values: 11–20, could indicate the completion of outer layer removal of carious dentin with Er:YAG laser, but there are some problems that must be addressed before the clinical application.