Abstract
Demineralized enamel grooves were exposed to an acid gel at pH=5 for 3 weeks after irradiation with a KrF excimer laser with a wavelength of 248 nm (total energy dose = 172 J/cm^2) or with the second harmonic wave of a Q-switched Nd : YAG laser with a wavelength of 532 nm (total energy dose=100 J/cm^2). The mineral distributions were assessed quantitatively by transversal microradiography. Compared with unlased controls, the mineral parameters, i.e., the lesion depth (l_d, μm) and the mineral loss value (ΔZ, vol%・μm) at the bottom of the grooves were not really different in the samples irradiated by either the pulsed excimer or the Nd : YAG laser, and a similar result was observed in the outer enamel surfaces near the grooves. This suggest that progression of demineralization in enamel lesions is not inhibited effectively by laser irradiation.
