The photobiomodulation (658, 830 and 904nm) on wound healing in histomorphometric analysis

Abstract Introduction: Photobiomodulation (PBM) assists in the processes of angiogenesis and cellular mitosis after skin lesion, contributing to tissue repair. Objective: to investigate the effects of photobiomodulation (during the proliferative phase) of 658 nm, 830 nm and 904 nm in the repair of skin lesions in an animal model. Method: 658 nm (G658), 830 nm (G830), 904 nm (G904) PBM, and control group (CG) integrated the research. We submitted the animals to an excisional wound and treatment at different wavelengths for 14 days. On the seventh and 14-1485004059th postoperative days, we calculated the area and percentage of lesion contraction. The animals were sacrificed on the 14-1485004056th postoperative day and cutaneous section of the injured region was collected for histomorphometric evaluation of the cellularity, neovascularization, thickness of the epidermis and volume density of collagen fibers colored with H&E and Picross Sirius respectively. For the statistical analysis, we applied the ANOVA test. Results: the G658 presented higher cellularity than GC (p = 0.03). The animals in the G658 group showed a significant increase in the neovascularization in relation to the CG (p = 0.01). Type III collagen significantly increased in G904 compared to G830 (p < 0.0001) and CG (p < 0.0001). The G658 had a significant increase in type III collagen fibers compared to G830 (p < 0.0001) and GC (p < 0.0001). We found no significant difference in the thickness of the epidermis, wound area, and in the percentage wound of contraction between the analyzed groups. Conclusion: PBM was effective to stimulate the tissue repair process, with better results for the 658 nm wavelength.