Effect of low-level laser irradiation on osteoblast proliferation and bone formation

J Biol Regul Homeost Agents. 2011 Oct-Dec;25(4):603-14.


Applications of laser therapy in biostimulation and healing injured tissues are widely described in medical literature. The present study focuses on the effects of laser irradiation on the growth rate and differentiation of human osteoblast-like cells seeded on titanium or zirconia surfaces. Cells were laser irradiated with low therapeutical doses at different intervals and the effects of irradiation were evaluated at each time-point. After 3 hours lasered cells showed an enhanced mitogen activity compared to non-lasered control cells and a higher alkaline phosphatase activity, marker of bone formation. At the same time, the mRNA of RUNX2 and OSTERIX, two genes involved in osteoblast differentiation, showed a clear decrease in lasered cells. This reached the lowest value 6 to 12 hours after irradiation, after which the transcripts started to increase, indicating that the laser treatment did promote the osteogenic potential of growth-induced cells. These results indicate that Low Level Laser Treatment (LLLT) stimulates osteogenic cell proliferation.

MeSH terms

  • Adult
  • Bone Matrix / radiation effects
  • Cell Proliferation / radiation effects
  • Cell Respiration / radiation effects
  • Cells, Cultured
  • Core Binding Factor Alpha 1 Subunit / genetics
  • Humans
  • Low-Level Light Therapy*
  • Middle Aged
  • Osteoblasts / radiation effects*
  • Osteogenesis / radiation effects*
  • Sp7 Transcription Factor
  • Transcription Factors / genetics


  • Core Binding Factor Alpha 1 Subunit
  • RUNX2 protein, human
  • Sp7 Transcription Factor
  • Sp7 protein, human
  • Transcription Factors