BACKGROUND AND OBJECTIVE: Thermal effects of direct exposure of the pulp chamber to CO2 laser irradiation were evaluated and potentially safe parameters for its clinical application were determined. STUDY DESIGN/ MATERIALS AND METHODS: Using conventional methods, the pulp chambers of freshly extracted primary cuspids were exposed and then subjected to CO2 laser irradiation at the following parameters: 2, 4, 6, 8, 10, 15, and 20 Watts power settings; 0.76 mm diameter spot size; total energy densities between 4-1,058 J/cm2; exposure time between .01-60 s. Exposures in the continuous wave mode were performed in some specimens. In others, single firings of a .01 s pulse duration and a 1 s pulse interval were conducted. Temperature measurements were conducted using a thermocouple and thermal camera. RESULTS: Significant statistical differences in maximum temperature rise on enamel were observed in groups that received total energy densities > or = 8 J/cm2 (P < or = 0.01); within the pulp chambers these were observed in groups that used > or = 44 J/cm2 (P < or = 0.01). CONCLUSION: Parameters appropriate for pulpotomy were observed at energy densities up to 176 J/cm2 in the continuous wave mode and 264 J/cm2 using single pulses, wherein temperature rises below 5.5 degrees C were recorded on tooth surface.
BACKGROUND AND OBJECTIVE: Thermal effects of direct exposure of the pulp chamber to CO2 laser irradiation were evaluated and potentially safe parameters for its clinical application were determined. STUDY DESIGN/ MATERIALS AND METHODS: Using conventional methods, the pulp chambers of freshly extracted primary cuspids were exposed and then subjected to CO2 laser irradiation at the following parameters: 2, 4, 6, 8, 10, 15, and 20 Watts power settings; 0.76 mm diameter spot size; total energy densities between 4-1,058 J/cm2; exposure time between .01-60 s. Exposures in the continuous wave mode were performed in some specimens. In others, single firings of a .01 s pulse duration and a 1 s pulse interval were conducted. Temperature measurements were conducted using a thermocouple and thermal camera. RESULTS: Significant statistical differences in maximum temperature rise on enamel were observed in groups that received total energy densities > or = 8 J/cm2 (P < or = 0.01); within the pulp chambers these were observed in groups that used > or = 44 J/cm2 (P < or = 0.01). CONCLUSION: Parameters appropriate for pulpotomy were observed at energy densities up to 176 J/cm2 in the continuous wave mode and 264 J/cm2 using single pulses, wherein temperature rises below 5.5 degrees C were recorded on tooth surface.