In vitro study of the effects of diode laser on dentin hypersensitivity and evaluation of intra-pulpal temperature variation

Objective To evaluate the efficacy and safety of different wavelengths of high-power diode lasers for the treatment of dentin hypersensitivity by analyzing morphological changes and temperature variation. Methods Human third molars were irradiated with four different wavelengths from five commercial brands. Temperature variation was measured using thermocouples, and morphological changes were assessed using scanning electron microscopy. Results Lasers with wavelengths of 940 nm, 976 nm, and 980 nm, used without a photoinitiator (1 Watt in continuous mode, applied in two 30-second irradiation phases with a 30-second interval), promoted dentinal tubule obliteration without causing thermal damage. Lasers with wavelengths of 808 nm, 940 nm, 976 nm, and 980 nm, when combined with a photoinitiator, resulted in even lower temperature variation compared to the non-photoinitiator groups, although no regular fused surface was observed. Conclusion Diode laser parameters, with the exception of Group 1, are potentially safe for dentinal tubule obliteration. However, the use of a photoinitiator may be necessary to achieve a more regular fused dentin surface, although this may increase temperature variation.