Effect of low-power laser irradiation on cell growth and procollagen synthesis of cultured fibroblasts

Lasers Surg Med. 2002;31(4):263-7. doi: 10.1002/lsm.10107.


Background and objectives: 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.

Study design/materials and 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells / radiation effects
  • Animals
  • Cell Division / radiation effects*
  • Cells, Cultured / radiation effects*
  • Fibroblasts / radiation effects*
  • In Vitro Techniques
  • Low-Level Light Therapy*
  • Mice
  • Procollagen / chemical synthesis*
  • Time Factors
  • Wound Healing / radiation effects


  • Procollagen