[Study of histostructure of fused human enamel by laser irradiation]

By applying the heat effect of laser, it was attempted to fuse artificial materials to tooth enamel with laser irradiation for direct bonding tooth restoration. At first the fusing methods of enamel were studied, and then the fused enamel was analized by polarized microscope, contact microradiogram, vickers hardness, electron probe microanalysis and X-ray diffraction. Furthermore the methods of fusing artificial materials to tooth enamel. Through these studies, the following results were obtained. 1. Among the pigments that were placed on the enamel surface, Fe2O3- particulate- dispersed agents solution was most suitable for the fusion of enamel, and the best irradiation condition was the focused beam of 20 J energy (20 W X 1.0 sec.). 2. Fused enamel, which is proved to be composed of not only hydroxyapatite but also alpha-tricalcium phosphate, is more radiopaoue than non-fused enamel and the birefringence is dissimilar also, but the hardness is the same. 3. It was possible to fuse artificial alpha-tricalcium phosphate to fused enamel, and the results of the analysis were the same as those mentioned before.