title: Effect of low-power laser irradiation on cell growth and procollagen synthesis of cultured fibroblasts.
abstract: OBJECTIVE
  In dentistry, low-power lasers have been used in the treatment of dentin hypersensitivity, gingivitis, periodontitis, and different forms of oral ulcers. This in vitro study focuses on the biostimulation of NIH-3T3 fibroblasts by a low-power Ga-As-pulsed laser.
  
  
  METHODS
  We have studied cell growth and procollagen synthesis of cultured fibroblasts submitted to low-power laser irradiation with energy densities varying from 3 to 5 J/cm(2) over a period of 1-6 days. The light source was a 120 mW Ga-As diode laser (lambda = 904 nm). Growth curves and procollagen immunoprecipitation were obtained.
  
  
  RESULTS
  Irradiation of 3 and 4 J/cm(2) increased the cell numbers about threefold to sixfold comparing to control cultures. However, this effect was restricted to a small range of energy densities since 5 J/cm(2) had no effect on cell growth. The energy density of 3 J/cm(2) remarkably increased cell growth, with no effect on procollagen synthesis, as demonstrated by the immunoprecipitation analysis.
  
  
  CONCLUSIONS
  Our results showed that a particular laser irradiation stimulates fibroblast proliferation, without impairing procollagen synthesis.
mesh_terms: D016475:3T3 Cells / Q000528:radiation effects; D000818:Animals; D002455:Cell Division / Q000528:radiation effects*; D002478:Cells, Cultured / Q000528:radiation effects*; D005347:Fibroblasts / Q000528:radiation effects*; D066298:In Vitro Techniques; D028022:Low-Level Light Therapy; D051379:Mice; D011347:Procollagen / Q000138:chemical synthesis*; D013997:Time Factors; D014945:Wound Healing / Q000528:radiation effects
chemical_list: D011347:Procollagen