title: Laser and light-emitting diode effects on pre-osteoblast growth and differentiation.
abstract: 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.
authors.affiliation: Bauru School of Dentistry, Bauru, Sao Paulo, Brazil.
authors.forename: Marina Tochetti
authors.initials: MT
authors.lastname: Pagin
authors.forename: Flávia Amadeu
authors.initials: FA
authors.lastname: de Oliveira
authors.forename: Rodrigo Cardoso
authors.initials: RC
authors.lastname: Oliveira
authors.forename: Adriana Campos Passanezi
authors.initials: AC
authors.lastname: Sant'Ana
authors.forename: Maria Lucia Rubo
authors.initials: ML
authors.lastname: de Rezende
authors.forename: Sebastião Luiz Aguiar
authors.initials: SL
authors.lastname: Greghi
authors.forename: Carla Andreotti
authors.initials: CA
authors.lastname: Damante
mesh_terms: D016475:3T3 Cells; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001861:Bone Regeneration / Q000528:radiation effects; D002454:Cell Differentiation / Q000528:radiation effects; D049109:Cell Proliferation / Q000528:radiation effects; D054023:Lasers, Semiconductor / Q000627:therapeutic use*; D008027:Light; D028022:Low-Level Light Therapy; D051379:Mice; D010006:Osteoblasts / Q000166:cytology* / Q000201:enzymology / Q000528:radiation effects*; D010789:Phototherapy
chemical_list: D000469:Alkaline Phosphatase