CO2 laser irradiation restores collagen and VEGF expressions of HPdLF on LPS contaminated titanium surface

Abstract

Laser irradiation is using to treat oral peri-implantitis instead of surgical curettage to removing bacteria and inflammatory granulation material adhered to the implant surface. However, there were few effects known about laser treatment for periodontal cell functions. Therefore, in this study, we investigated the effect of CO2 laser irradiation on titanium surface and human periodontal ligament fibroblasts (HPdLF) with or without lipopolysaccharide (LPS) treatment. HPdLF cells were cultured on polished and roughed titanium plates, with or without LPS. CO2 laser irradiated to the each culture of titanium surface. HPdLF proliferation, type I collagen, vascular endothelial growth factor (VEGF), and actin formation were evaluated. Actin was detected by phalloidin staining. Gene expression changes of type I collagen and VEGF in HPdLF were also analyzed by RT-PCR. CO2 laser irradiation did not changes on both titanium surface. HPdLF proliferation was suppressed until the culture day 7 by LPS addition on both surfaces. However, HPdLF adhesion and proliferation increased after CO2 laser irradiation on both titanium surfaces regardless of LPS treatment. Also, Type I collagen and VEGF productions of HPdLF increased after CO2 laser irradiation on both titanium surfaces with or without LPS treatment. CO2 laser irradiation of the titanium surface promoted growth and differentiation of HPdLF under LPS conditions, suggesting that induction of collagen production and angiogenesis for tissue regeneration can occur on irradiation-treated implant surfaces.