Pulpal space pressure and temperature changes from Nd:YAG laser irradiation of dentin

Objectives. To investigate pulpal space pressure and temperature after application of Nd:YAG laser, and high-speed diamond bur on dentin surface. Methods. One and 3 W Nd:YAG laser and high-speed diamond bur were used to remove dentine from twenty extracted premolars. The pulp chambers were monitored for pressure and temperature changes with a pressure transducer and thermocouple, respectively. Results. Regardless of the remaining dentin thickness (RDT), laser irradiation and high-speed diamond bur use generated an increase in pulpal space pressure and temperature (ANOVA and Fisherʹs LSD tests, P<0.001). Pressure and temperature increased with an increase in laser power. Three-Watt laser irradiation caused greater changes than 1 W (1.75 kPa and 1.31 °C, 0.53 kPa and 0.34 °C, respectively). Both pulpal space pressure (P<0.001) and temperature (P<0.005) increased as the RDT decreased. Conclusions. Laser irradiation and the use of a high-speed diamond bur generated an increase in pulpal space pressure and temperature. Pulpal space pressure and temperature increased with an increase in energy density of laser and a decrease in RDT.