ABSTRACT
Objective To analyze the influence of a dental caries phototherapy device using neodymium-yttrium-aluminum-garnet (Nd:YAG) laser on the temperature of tooth pulp chamber of different sites and morphologies under different irradiation duration and power. Methods Fifty intact isolated teeth were collected and randomly divided into middle incisor group, upper right first premolar group, upper right second molar group, upper left first premolar group, and upper left second molar group. Each experimental group was irradiated according to the laser power 1.5, 1.6, 1.7, 1.8, 1.9 and 2.0 W, and the irradiation duration 30, 60, 90 s. The temperature rise of the pulp chamber was recorded with a thermocouple thermometer. Results After the laser irradiation, the temperature of the tooth pulp chamber increased, and the temperature rise was less than 5.5℃, i.e. the threshold leading to the dental pulp necrosis. Conclusions The use of laser to prevent dental caries will increase the temperature of the tooth pulp chamber, but the temperature rise in the range of 5.5 ° C is relatively safe and will not cause irreversible damage to the pulp tissue.