Pulp Temperature Increases following Caries Removal by CO2Laser

Abstract

Previous papers have described a number of beneficial effects of the CO2 laser on teeth in vitro. The aim of the present investigation is to define optimal CO2 laser irradiation parameters when the laser is used for caries removal. MOD cavities were drilled on extracted teeth. Their root canals furthermore were prepared for insertion of a thermocouple probe into the pulp chamber. Different conditions of laser firing were applied on the bottom of the cavity and induced temperature increase in the chamber space was recorded. In the case of serially firings, the energy density was unvaryingly settled at 280 J/cm2/pulse. Secondary temperature increases (below 2.2°C) were found to be tolerable for the pulp, under the following conditions: pulse width ≤1000 msec, pulse periodicity ≤1 Hz, volley firing ≤10 successive shots, and intervals between successive volley firings, 30 to 60 sec. Moreover, a dentin wall of ≥1.5 mm between the cavity and chamber provides good protection against heating when using single shots up to 1275 J/cm2 energy density. The optimal parameters set forth in this study should facilitate further animal and in vivo experimentation.