Green Light Photobiomodulation: A Systematic Review of New Approaches for Treating Bone Repair.

Background: Green light photobiomodulation (GPBM, 500-565 nm) promotes tissue healing, reduces inflammation, and alleviates pain, with emerging potential in bone repair. This review evaluates GPBM's therapeutic effects on bone-related cells (proliferation, differentiation, migration), inflammation, vascularization, and neuronal responses. Methods: We assessed the influence of different GPBM parameters, possible underlying molecular mechanisms, and prospects for in vivo applications based on available studies. Results: GPBM acts through mitochondria, opsins, and transient receptor potential vanilloid (TRPV) channels. The most effective irradiation method uses low irradiance (5.3-100 mW/cm2) with a single exposure of ∼5 J/cm2. Excessively low irradiance is ineffective, while excessively high irradiance may cause inhibitory effects. GPBM enhances bone-related cell functions, suppresses inflammation, and promotes vascular and neuronal responses. Conclusions: GPBM shows promise for bone repair, but further research is needed to optimize parameters, clarify molecular mechanisms, and standardize clinical trial protocols to ensure reliable in vivo outcomes.