Dosage Effects of an 810 nm Diode Laser on the Proliferation and Growth Factor Expression of Human Gingival Fibroblasts

Abstract

Introduction: A substantial amount of evidence supports the positive effect of photobiomodulation on the proliferation and differentiation of various cell types. Several laser wavelengths have been used for wound healing improvement, and their actual outcome depends on the settings utilized during irradiation. However, the heterogeneous wavelengths and laser settings applied in the existing literature make it difficult to draw solid conclusions and comparison of different studies. The aim of the present study is to evaluate and compare the effects of various doses of laser energy, provided by an 810 nm diode, on human gingival fibroblasts in terms of proliferation and expression of growth factors with a pivotal role in wound healing. Methods: Human gingival fibroblasts were cultured on plastic tissue culture and irradiated with 2, 4, 6 or 12 J/cm2 . The effects of the low-level laser therapy (LLLT) using an 810 nm diode laser on growth factor expression (EGF, TGF and VEGF) were evaluated by qPCR at 72 hours and 7 days after irradiation. Cell proliferation was evaluated at 24, 48 and 72 hours after LLLT using MTT assay. Results: Energy density of 12 J/cm2 provoked irradiated gingival fibroblasts to demonstrate significantly higher proliferation as well as higher gene expression of Col1, VEGF and EGF. LLLT positive effects were obvious up to 7 days post-irradiation. Conclusion: LLLT with 810 nm presents beneficial effects on proliferation, collagen production and growth factor expression in human gingival fibroblast cells. The application of 12 J/cm2 can be suggested as the optimal energy density for the enhancement of the wound healing process.

Therapeutic Potential of Low-level Laser Photobiomodulation on Adjuvant Induced Temporomandibular Joint Arthritis in A Rat Model

“…The therapeutic potential of LLLT could be attributed to its inductive effect for the secretion of endogenous opioids, increasing vasodilatation, stimulating tissue regeneration, and reducing inflammation through the reduction of prostaglandin E2 and cyclo-oxygenase 2 (COX-2) release, 20 as well as decreasing reactive oxygen species (ROS) levels, mRNA expression of phospholipase A2 and TNF-α levels allowing LLLT to be a good alternative to NSAIDs avoiding any possible drugs' side effects. 21 In a study conducted by Karoussis et al, 22 LLLT was found to enhance the expression of epidermal growth factor (EGF), transforming growth factor (TGF), and vascular endothelial growth factor (VEGF) as well as stimulating collagen production and cellular proliferation in human fibroblast cells.…”