[Effects of Nd:YAG laser irradiation on acid resistance of defective rat enamel].

As Colchicine is an inhibitor of the function of microtubles, administration of it causes abnormal amelogenesis in the teeth of experimental animals. The purposes of this study were to characterize the defective rat enamel which was formed after a single administration of colchicine, and to examine the effects of Nd:YAG laser with continuous wave on the acid resistance of the defective enamel. The following results were obtained: 1) On about the 10th day after a single subcutaneous injection of colchicine with a dose of 1.5 mg/kg of body weight, the defective enamel was found on the incisor as white bands with rough surface. 2) The defective enamel had less resistance to the acid demineralization than that of normal enamel. 3) After irradiation of Nd:YAG laser with continuous wave, the defective enamel surface became smooth and the small defects on the enamel surface disappeared. 4) After irradiation of Nd:YAG laser, the resistant level of the defective enamel to the acid demineralization increased up to that of normal enamel. The results suggest that Nd:YAG laser irradiation on human teeth with hypomineralized enamel may be effective for the prevention of dental caries.