title: Effects of low-level laser therapy on human osteoblastic cells grown on titanium.
abstract: The aim of this study was to investigate the effects of low-level laser therapy (LLLT) by using gallium aluminum arsenide (GaAlAs) diode laser on human osteoblastic cells grown on titanium (Ti). Osteoblastic cells were obtained by enzymatic digestion of human alveolar bone and cultured on Ti discs for up to 17 days. Cells were exposed to LLLT at 3 J/cm2 (wavelength of 780 nm) at days 3 and 7 and non-irradiated cultures were used as control. LLLT treatment did not influence culture growth, ALP activity, and mineralized matrix formation. Analysis of cultures by epifluorescence microscopy revealed an area without cells in LLLT treated cultures, which was repopulated latter with proliferative and less differentiated cells. Gene expression of ALP, OC, BSP, and BMP-7 was higher in LLLT treated cultures, while Runx2, OPN, and OPG were lower. These results indicate that LLLT modulates cell responses in a complex way stimulating osteoblastic differentiation, which suggests possible benefits on implant osseointegration despite a transient deleterious effect immediately after laser irradiation.
authors.affiliation: Cell Culture Laboratory, Ribeirão Preto Dental School, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Alice Dias
authors.initials: AD
authors.lastname: Petri
authors.forename: Lucas Novaes
authors.initials: LN
authors.lastname: Teixeira
authors.forename: Grasiele Edilaine
authors.initials: GE
authors.lastname: Crippa
authors.forename: Marcio Mateus
authors.initials: MM
authors.lastname: Beloti
authors.forename: Paulo Tambasco
authors.initials: PT
authors.lastname: de Oliveira
authors.forename: Adalberto Luiz
authors.initials: AL
authors.lastname: Rosa
mesh_terms: D000469:Alkaline Phosphatase / Q000096:biosynthesis / Q000235:genetics; D000704:Analysis of Variance; D001857:Bone Matrix / Q000254:growth & development*; D055419:Bone Morphogenetic Protein 7 / Q000096:biosynthesis / Q000235:genetics; D002478:Cells, Cultured / Q000528:radiation effects; D024042:Collagen Type I / Q000096:biosynthesis / Q000235:genetics; D050659:Core Binding Factor Alpha 1 Subunit / Q000096:biosynthesis / Q000235:genetics; D015870:Gene Expression / Q000528:radiation effects*; D006801:Humans; D058574:Integrin-Binding Sialoprotein / Q000096:biosynthesis / Q000235:genetics; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis / Q000235:genetics; D054023:Lasers, Semiconductor / Q000627:therapeutic use; D028022:Low-Level Light Therapy; D016348:Osseointegration / Q000528:radiation effects*; D010006:Osteoblasts / Q000378:metabolism / Q000528:radiation effects*; D015675:Osteocalcin / Q000096:biosynthesis / Q000235:genetics; D053495:Osteopontin / Q000096:biosynthesis / Q000235:genetics; D053244:Osteoprotegerin / Q000096:biosynthesis / Q000235:genetics; D053245:RANK Ligand / Q000096:biosynthesis / Q000235:genetics; D018709:Statistics, Nonparametric; D014025:Titanium
chemical_list: D055419:Bone Morphogenetic Protein 7; D024042:Collagen Type I; D050659:Core Binding Factor Alpha 1 Subunit; D058574:Integrin-Binding Sialoprotein; D053244:Osteoprotegerin; D053245:RANK Ligand; C493709:RUNX2 protein, human; D015675:Osteocalcin; D053495:Osteopontin; D018799:Intercellular Adhesion Molecule-1; D014025:Titanium; D000469:Alkaline Phosphatase