Comparative analysis of the light parameters of red and near‐infrared diode lasers to induce photobiomodulation on fibroblasts and keratinocytes: An in vitro study

Abstract Background Photobiomodulation (PBM) depends on the use of non‐ionizing light energy to trigger photochemical changes, particularly in light‐sensitive mitochondrial structures. It triggers proliferation and the metabolic activity of the cells, primarily by utilizing the energy from the near‐infrared to the red wavelength of the light. Purpose This in vitro study has analyzed comparatively the most appropriate energy doses and wavelengths to induce PBM on keratinocytes and fibroblasts for the accelerated wound healing process. Methods 1, 3, and 5 J/cm 2 energy densities of 655 and 808‐nm diode lasers were used to promote cell proliferation and wound healing process. Scratch assay and MTT analysis were performed on keratinocytes and fibroblasts for wound closure and cell proliferation after the triple light applications, respectively. Results 655‐nm of wavelength was more successful on keratinocytes to induce wound healing and cell proliferation, whereas 808‐nm of wavelength was so effective on fibroblasts to heal the wounds totally and it induced cell proliferation almost 3 times compared to the untreated control group. Conclusion This study revealed that PBM with 655 and 808 nm of wavelengths was effective to speed up the wound healing process at specific energy densities. In general 808‐nm of wavelength was more successful. However, the proper wavelength and the energy density may differ according to the cell type. Thus, every light parameter should be chosen properly to obtain better outcomes during PBM applications.