Purpose: To evaluate the effect of laser irradiation on cell proliferation of periodontal and gingival fibroblasts with a low energy level laser. Materials and Methods: Periodontal and gingival fibroblast cultures were obtained from the tissue bank of the Universidad del Valle (Cali, Colombia). After 24 h of incubation, they were irradiated while in the logarithmic phase of growth, using a low energy level laser (Photon LASE As-Ga-Al), operated at 37 mW, 830 nm wavelength at an energy level of 3.75 J/cm2. The rate of cell proliferation was evaluated in experimental and control cultures by the XTT test (Roche). The percentage of cytotoxicity was measured by the LDH test (Roche). The rate of proliferation was measured 24, 48, 72, 96, 120, and 144 h after irradiation. The cell cytotoxicity was measured 24 h after irradiation. Results: The irradiation protocol used in this study did not cause cytotoxicity in any of the cell lines evaluated. The rate of gingival fibroblast proliferation was higher in the experimental culture than in the controls, although the difference was not statistically significant, while for periodontal fibroblasts the rate of cell proliferation was higher in the control group, but not significantly differently. Conclusion: The cytoxicity test indicates that this laser treatment protocol is safe for both cell lines. There are no statistically significant differences in the rate of cell proliferation between or within groups.
Keywords: periodontal fibroblasts, gingival fibroblasts, low energy level laser, orthodontic tooth movement