Laser and light-emitting diode effects on pre-osteoblast growth and differentiation

• DOI: 10.1007/s10103-012-1238-5
• Publication Date: 2012-11-23T08:04:08Z
• Authors: Marina Tochetti P...; Flávia Amadeu de ...; Rodrigo Cardoso O...; Adriana Campos Pa...; Maria Lucia Rubo ...; Sebastião Luiz Ag...; Carla Andreotti D...
• Keywords: Bone Regeneration; Osteoblasts; Light; Cell Differentiation; 3T3 Cells; Phototherapy; Alkaline Phosphatase; Mice; 03 medical and health sciences; 0302 clinical medicine; Animals; Lasers, Semiconductor; Low-Level Light Therapy; Cell Proliferation

The acceleration of bone regeneration by low-intensity laser irradiation may hold potential benefits in clinical therapy in orthopedics and dentistry. The purpose of this study is to compare the effects of light-emitting diode (LED) and laser on pre-osteoblast MC3T3 proliferation and differentiation. Cells were irradiated with red, infrared, and LED (3 and 5 J/cm(2)). Lasers had a power density of 1 W/cm(2) and irradiation time of 2 and 5 s. LED had a power density of 60 mW/cm(2) and irradiation time of 50 and 83 s. Control group did not receive irradiation. Cell growth was assessed by a colorimetric test (MTT) (24, 48, 72, and 96 h), and cell differentiation was evaluated by alkaline phosphatase (ALP) quantification after growth in osteogenic medium (72 and 96 h and 7 and 14 days). At 24 h, the cell growth was enhanced 3.6 times by LED (5 J/cm(2)), 6.8 times by red laser (3 J/cm(2)), and 10.1 times by red laser (5 J/cm(2)) in relation to control group (p < 0.05). At the other periods, there was no influence of irradiation on cell growth (p > 0.05). The production of ALP was not influenced by irradiation at any period of time (p > 0.05). Low-intensity laser and LED have similar effects on stimulation of cell growth, but no effect on cell differentiation.