title: The Effects of Low Level Laser Therapy on the Expression of Collagen Type I Gene and Proliferation of Human Gingival Fibroblasts (Hgf3-Pi 53): in vitro Study.
abstract: OBJECTIVE
  Recent investigations show that both proliferation and secretion of macromolecules by cells can be regulated by low level laser therapy (LLLT). The aim of this study was to determine whether LLLT could induce a bio-stimulatory effects on human gingival fibroblasts (HGF3-PI 53). Therefore, the effect of laser irradiation on human gingival cell proliferation and collagen type I gene expression was studied.
  
  
  METHODS
  HGF3-PI 53 were cultured in 96-well plate and then irradiated with LLLT gallium-aluminum-arsenide (Ga-Al-As), 810 nm, 50 mW diode laser (energy: 4 J/cm(2)) for three consecutive days. The cell proliferation was measured on days 1, 2 and 3 after irradiation with LLLT using MTT assay. Real time PCR analysis was utilized on day 3 to evaluate the expression of collagen type I gene. Results : Evaluation of cellular proliferation, one day after laser treatment showed no difference compared to control group. But on days 2 and 3, significant increase in proliferation was observed in the irradiated cell populations in comparison to the control group. Treatment of HGF3-PI 53 by laser resulted in a significant increase in collagen I gene expression on 3 day.
  
  
  CONCLUSIONS
  The results demonstrated that LLLT stimulated human gingival fibroblast proliferation as well as collagen type I gene expression in vitro.
authors.affiliation: Oral& Maxillofacial Diseases Research Center, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Frozanfar
authors.affiliation: Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ramezani
authors.affiliation: Oral& Maxillofacial Diseases Research Center, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Amin
authors.initials: A
authors.lastname: Rahpeyma
authors.affiliation: Oral& Maxillofacial Diseases Research Center, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Saeedeh
authors.initials: S
authors.lastname: Khajehahmadi
authors.affiliation: Dental Research Center, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Arbab
keywords: Collagen type I; Human gingival fibroblasts; Low level laser therapy