in vitro study of er:yag and er, cr:ysgg laser irradiation on human gingival fibroblast cell line

the ultimate goal of the periodontal treatments is a regeneration of periodontium. recently, laser irradiations are commonly used to improve wound repair. because of many controversies about the effects of laser on soft tissue regeneration, more in vitro studies are still needed. the aim of the present in vitro study was to compare the effects of different doses of er:yag (erbium-doped:yttrium, aluminum, garnet) and er, cr:ysgg (erbium, chromium-doped: yttrium, scandium, gallium, garnet) laser treatment on human gingival fibroblasts (hgf) proliferation. in this randomized single-blind controlled in vitro trial, hgf cells were irradiated using er:yag and er, cr:ysgg laser for 10 and 30 seconds or remained unexposed as a control group. after a culture period of 24 and 48 hours, hgf cell proliferation was evaluated by mtt assay. the data were subjected to one-sided analysis of variance and tukey multiple comparison tests. our results showed er:yag application for 10 and 30 seconds as well as er, cr:ysgg irradiation for 10 and 30 seconds induced statistically significant ( p <0.05) proliferation of hgf cells as compared with the control at 24 hours up to 18.39%, 26.22%, 21.21%, and 17.06% respectively. in 48 hour incubations, er:yag and er, cr:ysgg irradiation for 10 and 30 seconds significantly increased cellular proliferation up to 22.9%, 32.24%, 30.52% and 30.02% respectively ( p <0.05). this study demonstrates that er:yag and er, cr:ysgg laser significantly increased hgf cell proliferation compared to the control specimens. this higher proliferation can lead to increased wound repair in clinical conditions.