Thermal Changes in Root Surface of Primary Teeth During Root Canal Treatment With Diode Lasers: An In Vitro Study

Abstract Introduction: Increased temperature due to the application of laser during root canal disinfection may damage periodontium, alveolar bone, and permanent dental germ. The aim of this study was to evaluate the temperature increase of the external surface of primary roots due to the application of ۸۱۰ nm and ۹۸۰ nm diode lasers.Methods: A total of ۵۸ extracted human primary teeth were prepared and randomly divided into two groups: (a) ۸۱۰ nm diode laser and (b) ۹۸۰ nm diode laser. Then, each group was divided into ۴ subgroups based on the location of the temperature measurement, including subgroup ۱: external root surface of primary anterior roots (A); subgroup ۲: external root surface of posterior teeth at inter-root space (IS); subgroup ۳: external root surface of posterior teeth at outer-root space (OS) and subgroup ۴: external surface of furcation area of posterior teeth (F).Results: The mean temperature rise in group a (۷.۰۲±۲.۹۵ºC) was less than that of group b (۱۰.۶۲±۴.۵۹ºC) (P < ۰.۰۰۱). Also, a significant difference was found between the laser groups in terms of the mean temperature rise of the external root surface at IS, OS and F, with higher temperature increase occurring in all points in laser b. The comparison of irradiation points in each laser showed a higher mean temperature rise for IS than OS, but this difference was only significant in group b (P < ۰.۰۰۱).Conclusion: Within the studied parameters, ۸۱۰ nm and ۹۸۰ nm diode lasers should be used cautiously in primary root canals because of their temperature rise during their application. Keywords: Diode laser temperature rise primary teeth