Effect of low-power laser irradiation on protein synthesis and ultrastructure of human gingival fibroblasts

Background and Objectives: Low-power lasers improve wound healing. Cell proliferation and protein secretion are important steps of this process. The aim of this study was to analyze both protein synthesis and ultrastructural morphology of human gingival fibroblasts irradiated by a low-power laser. Study Design/Materials and Methods: The cell line FMM1 was grown in nutritional deficit. Laser irradiation was carried out with a gallium-aluminum-arsenate (Ga-Al-As) diode laser (904 nm, 120 mW, energy density of 3J/cm(2) 2). The protein synthesis analysis and ultrastructural morphology of control (non-irradiated) and irradiated cultures were obtained. Results: There were changes in the structure of cytoplasm organelles of treated cells. The procollagen was not altered by the laser irradiation; however, there were a significant reduction of the amount of protein in the DMEM conditioned by irradiated cells. Conclusions: Low-power laser irradiation causes ultrastructural changes in cultured fibroblasts. We suggest that these alterations may lead to disturbances in the collagen metabolism. (C) 2004 Wiley-Liss, Inc.