“The effect of diode laser 940 nm and 445 nm on the rise in temperature of a pulp simulating material: in vitro study”

Purpose: The purpose of the current study was to compare the effect of two diode lasers with wavelengths (940 nm and 445 nm) using different powers (0.5 W and 1 W) on the temperature rise of a pulp simulating material. Materials and methods: This in vitro study involved a total number of 36 permanent molars. The samples were randomly divided into two groups according to different wavelengths (940 nm and 445 nm); 18 teeth were included in each group. Each group was subdivided according to the power settings (0.5 and 1 W) into two subgroups with nine teeth in each subgroup. The occlusal cavities were prepared in sound molars leaving a 1 mm dentin bridge. The selected wavelengths were applied for 5 s with an output of 0.5 W and 1 W. The applied energy was 2.5 J and 5 J. A thermocouple was inserted in the pulp chamber filled with a pulp simulating material, and the temperature changes were monitored in °C throughout the procedure. The data collected were tabulated and statistically analyzed by using tests of normality (Kolmogorov–Smirnov and Shapiro–Wilk tests). Results: The results had shown that the 940 nm has a higher statistical significance difference on the mean temperature in comparison to the 445 nm at 0.5 W. The 940 nm showed a higher temperature rise compared to the 445 nm using the 1 W, yet it is insignificant. However, there was no statistically significant difference in the temperature rise between both powers (0.5W and 1 W) in both wavelengths (445 nm and 940 nm). Nevertheless, all the temperature rises that occurred did not exceed 2 °C. Conclusion: Both wavelengths increased the temperature of the pulp simulating material. The 940 nm caused a higher increase in temperature. The temperature elevations were within the safe range, providing that both wavelengths can be used safely with the used parameters. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.