Intrapulpal temperature during preparation with the Er:YAG laser compared to the conventional burr: an in vitro study.

OBJECTIVE The authors explored whether the preparation with the Er:YAG laser showed a difference in increase of intrapulpal temperature in comparison to the conventional burr. SUMMARY BACKGROUND DATA The effect of preparation with the Er:YAG laser on the temperature in the pulp is probably the biggest problem in using the laser for preparation of dental hard tissue. METHODS The effect on the temperature in the pulp was studied on extracted human incisors and canines in vitro in palatinal class I cavities. The temperature during preparation with the Er:YAG laser was compared to that recorded during conventional tactile preparation with a diamond burr. The study was designed so that the pulpal cavity and the measuring probe were kept at a constant temperature of 37 degrees C from the root upward while the crown, which was thermally isolated, was exposed to preparation and cooling agents. RESULTS During preparation with the laser, there was a temperature drop after a few seconds from 37 degrees C to 25 degrees C to 30 degrees C due to cooling with water and air. Even with trepanation, there was only an increase in temperature in the pulp when the temperature measuring probe was hit directly by the laser beam. With conventional preparation in comparison, even before trepanation there was a rise in temperature to more than 60 degrees C. CONCLUSIONS The reduction in pain with clinical use of the Er:YAG laser for class V cavities has already been mentioned in publications and could, in addition to the nontactile preparation, be due to the lesser increase in intrapulpal temperature during the laser preparation in comparison to the conventional burr.