title: Effect and clinical implications of the low-energy diode laser on bone cell proliferation.
abstract: Laser is a simple, noninvasive technique that has proven useful for treating damaged tissue. However, its effects on bone regeneration and the mechanisms involved are poorly understood. The objective of this study was to evaluate the effects on MG-63 cell proliferation of application of a pulsed diode laser (Ezlase) of 940 nm at low energy levels. After 24 hr of culture, osteoblasts underwent pulsed laser radiation at 0.5, 1, 1.5, and 2 W and fluences of 1-5 J. A control group was not irradiated. After the treatment, cells were incubated for 24 hr, and cell proliferation was analyzed using a spectrophotometric measure of cell respiration (MTT assay). Results were expressed as percentage proliferation versus controls. At 24-hr culture, cell proliferation was increased in laser-treated cells at intensities of 0.5, 1, and 1.5 W/cm(2) versus controls; the energy density was positively correlated with cell growth, which reached a peak at 3 J and decreased at higher fluences. The use of pulsed low-level laser with low-energy density range thus appears to exert a biostimulatory effect on bone tissue. Although the data on cell proliferation are robust, in-depth investigation is required into the effect of these irradiation doses on other cell parameters. The present findings demonstrate that laser therapy could be highly useful in tissue regeneration in different clinical settings, including nursing, physical therapy, dentistry, and traumatology.
authors.affiliation: 1Biomedical Group (BIO277), Department of Nursing, Faculty of Health Sciences, University of Granada, Granada, Spain.
authors.forename: Rosa Medina
authors.initials: RM
authors.lastname: Huertas
authors.forename: Elvira De
authors.initials: ED
authors.lastname: Luna-Bertos
authors.forename: Javier
authors.initials: J
authors.lastname: Ramos-Torrecillas
authors.forename: Francisco Medina
authors.initials: FM
authors.lastname: Leyva
authors.forename: Concepción
authors.initials: C
authors.lastname: Ruiz
authors.forename: Olga
authors.initials: O
authors.lastname: García-Martínez
mesh_terms: D001842:Bone and Bones / Q000166:cytology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D006801:Humans; D028022:Low-Level Light Therapy
keywords: bone; cell growth; cell proliferation; diode laser; osteoblasts