Effect of diode laser irradiation on the survival rate of gingival fibroblast cell cultures

Background and Objective The present study is part of a basic research program investigating the cellular effects of the GaAlAs‐diode laser with a wavelength of 810 nm on human periodontal tissues. The aim of the investigation was to evaluate the effects of the laser treatment on the survival rate of human gingival fibroblasts (HGF) in monolayer cell culture at different power settings and durations. Study Design/Materials and Methods HGF were obtained from a human gingival connective tissue explant. Cells were cultured on 24‐well tissue culture plates. One hundred and thirty multi well cell cultures were laser treated. The variable parameters were power output (0.5–2.5 W) and exposure time (60–240 seconds per well). The cultures were analyzed by means of trypan blue staining, and the cell numbers counted under a light microscope. Photographs before and after irradiation were taken and evaluated. Results Depending on different settings, the laser irradiation caused significant (P