Effect of Nd:YAG Low Level Laser Therapy on Human Gingival Fibroblasts.

Andreas S Gkogkos,Ioannis K Karoussis,Ioannis D Prevezanos,Kleopatra E Marcopoulou,Ioannis A Vrotsos,Kyriaki Kyriakidou

doi:10.1155/2015/258941

Andreas S Gkogkos, Ioannis K Karoussis + Show 4 more

Open Access

https://doi.org/10.1155/2015/258941

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Abstract

Aim. To evaluate the effect of Low Level Laser Therapy (LLLT) on human gingival fibroblasts in terms of proliferation and growth factors' secretion (EGF, bFGF, and VEGF). Materials and Methods. Primary cultures of keratinized mucosa fibroblasts were irradiated by a Nd:YAG laser 1064 nm with the following energy densities: 2.6 J/cm2, 5.3 J/cm2, 7.9 J/cm2, and 15.8 J/cm2. Controls were not irradiated. Cultures were examined for cell proliferation and growth factors' secretion after 24, 48, and 72 hours. All experimental procedures were performed in duplicate. Data were analyzed by Student's t-test (p < 0.05). Results. All laser-irradiation doses applied promoted a higher cell proliferation at 48 hours in a dose-response relationship compared to controls. This difference reached statistical significance for the cultures receiving 15.8 J/cm2 (p = 0.03). Regarding EGF, all laser irradiation doses applied promoted a higher secretion at 48 hours in a reverse dose-response pattern compared to controls. This difference reached statistical significance for the cultures receiving 2.6 J/cm2 (p = 0.04). EGF levels at the other time points, bFGF, and VEGF showed a random variation between the groups. Conclusion. Within the limits of this study, LLLT (Nd:YAG) may induce gingival fibroblasts' proliferation and upregulate the secretion of EGF. Further studies are needed to confirm these results.

Highlights

Laser devices, almost 50 years after their introduction, find numerous applications in health sciences and are used successfully in several dental specialties
Within the limitations of this study, it appeared that treatment with low power laser (LLLT) using neodymium-doped yttrium aluminum garnet (Nd):YAG laser, in irradiation time of 120 s, resulted in a statistically significant increase of cells’ population (p = 0.03), compared to the control group, 48 hours after irradiation
We found that all laser-irradiation doses applied promoted a higher secretion of epidermal growth factor (EGF), at 48 hours, compared to control group

Summary

Introduction

Almost 50 years after their introduction, find numerous applications in health sciences and are used successfully in several dental specialties. At a high output power, lasers cause thermomechanical ablation used for incisions and hard or soft tissue removal. At a low output power (0.2–0.5 W), referred to as Low Level Laser Therapy (LLLT), they may present a stimulatory effect, via a photobiologic phenomenon (photobiomodulation), promoting tissue healing, reducing inflammation, and inducing analgesia [1]. Growth factors represent keystones in the wound healing procedures. Blood-derived fibroblast growth factor (bFGF) has anti-inflammatory effect [3], vascular endothelial growth factor (VEGF) plays a role in angiogenesis, inflammation, and wound healing [4, 5], and epidermal growth factor (EGF) promotes a dose-dependent migratory response in gingival fibroblasts accelerating wound healing [6]

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