Surface temperature during cavity preparation on human tooth by Er:YAG laser irradiation

This study deals with temperature measurement of enamel surface of the human tooth during cavity preparation by the irradiation of Er:YAG laser beam. Surface temperature is measured using a three-color pyrometer and the influence of laser condition is investigated. In addition, prepared cavity is measured with a three-dimensional surface profiling system. As a result, the surface temperature during Er:YAG laser irradiation ranges from 220 to 410 °C depending on the laser energy density and it is considerably lower than the melting point of human enamel (1614 °C). The increase in cavity volume is small at a temperature of irradiated area lower than T = 320 °C, but it increases rapidly at a higher temperature. Therefore it is possible to control the cavity volume by measuring the surface temperature without physically damaging the enamel surface.