Scanning electron microscopic study of dentin lased with argon, CO2, and Nd:YAG laser.

The purpose of this study was to compare morphological changes on the dentin surface induced by laser light delivered perpendicular or parallel to the dentin surface. The surface of the dentin slices and the root canal walls were lased with argon, CO2, and Nd:YAG lasers. When the laser beam was parallel to the dentin, the effects of the laser energy ranged from no effect to eroding and melting of the smear layer and dentin in the samples. When the laser beam was perpendicular to the surface, all three lasers produced well-shaped craters. From this, it was concluded that the angle of the laser beam in relation to the target surface can be a deciding factor of how much energy will be absorbed by the dentin and consequently of the morphological changes induced by the laser.