Comparative analysis of 650 nm and 450 nm diode lasers in photobiomodulation for wound healing after tooth extraction in rabbits.

Photobiomodulation therapy (PBMT), which involves both stimulatory and inhibitory biological responses to light, represents a critical area of research requiring further in-depth exploration. This study aimed to evaluate and compare the effects of 650 nm and 450 nm diode lasers on wound healing following tooth extraction in a rabbit model. Local anesthesia was used. A continuous-wave (CW) diode laser with wavelengths of 650 then 450 were used on wound after tooth extraction in 30 rabbits divided into three groups randomly and equally separated groups: control group (G1), 650 nm group (G2) and 450 nm group (G3), with laser parameters determined based on a prior pilot study in rabbits. The energy density for a 30-second exposure was 7.64 J/cm². The power output and the power density were 200 mW and 254 mW per cm², respectively. By day 7, 70% of rabbits in the G2 exhibited pink gingival tissue, compared to only 40% in the G3.Healing outcomes demonstrated statistically significant (p < 0.05) in G2in the gingival color and thickness relative to those G1 and G3.By day 14, none of theG1 displayed severe congestion, whereas G2 showed normal tissue recovery without pathological secretion(only two rabbits in G3 showed suppuration).Histopathological analysis revealed that 650 nm PBMT stimulated partial epithelialization and collagen deposition by day 7, with further enhancement by day 14. The 650 nm wavelength demonstrated superior healing effects, characterized by increased pink gingival tissue, reduced bleeding, and absence of inflammation. Photobiomodulation therapy (PBM) accelerates wound healing and is effective in reducing inflammation. Further research is needed to optimize wavelength selection.Clinical trial number Not applicable.