Abstract
A peliminary experiments were carried out on the caries prevention with Nd-YAG laser using hamster molar teeth and intact human permanent teeth in vitro. Molar teeth of conventional hamsters were obtained from 9-14 weeks age.
Human and hamster teeth were irradiated with AO Q-sw pulse and normal pulse of Nd-YAG laser at the various energy density.
The results were as follows.
1) There were the correlations between the value of energy density and the degree of the acquired acid-resistance of the dental enamel with AO Q-sw pulse and normal pulse of Nd-YAG laser. The pattern of acid-resistance with the two different kinds of pulses on the hamster teeth were similar to those of the human teeth.
2) The lased enamel of hamster teeth indicated a grazing of surface enamel with scanning electron microscopic observation, and the morphological changes were also obtained from the human teeth. However, the degree of the morphological changes of the hamster teeth were harder than those of human teeth at the same energy density.
3) The hamster teeth indicated the less variation in regard to the level of acquired acid-resistance with laser irradiatuin compared with the human teeth.
These results suggested that the hamster is a good model for the experiment of acid-resistance with laser irradiation.
