Effect of wavelength on low-intensity laser irradiation-stimulated cell proliferation in vitro.

BACKGROUND AND OBJECTIVES There exist contradictory reports about low-intensity laser light-stimulated cell proliferation. The purpose of this study was to determine the effect of wavelength on proliferation of cultured murine cells. STUDY DESIGN/MATERIALS AND METHODS Proliferation of primary cell cultures was measured after irradiation with varying laser wavelengths. RESULTS Fibroblasts proliferated faster than endothelial cells in response to laser irradiation. Maximum cell proliferation occurred with 665 and 675 nm light, whereas 810 nm light was inhibitory to fibroblasts. CONCLUSIONS These observations suggest that both wavelength and cell type influence the cell proliferation response to low-intensity laser irradiation.