title: Effects of low-level laser therapy on bone formed after distraction osteogenesis.
abstract: This study evaluated the effect of low-level laser therapy (LLLT) on the chemical composition, crystallinity and crystalline structure of bone at the site of distraction osteogenesis. Five rabbits were subjected to distraction osteogenesis (latency = 3 days; rate and frequency = 0.7 mm/day for 7 days; consolidation = 10 days), and three were given LLLT with arsenide-gallium-aluminum (AsGaAl; 830 nm, 40 mW): 10 J/cm(2) dose per spot, applied directly to the distraction osteogenesis site during the consolidation stage at 48 h intervals. Samples were harvested at the end of the consolidation stage. X-ray fluorescence and X-ray diffraction were used to analyze chemical composition, crystallinity and crystalline structure of bone at the distraction osteogenesis site. The analysis of chemical composition and calcium (Ca) and phosphorus (P) ratios revealed greater mineralization in the LLLT group. Diffractograms showed that the crystalline structure of the samples was similar to that of hydroxyapatites. Crystallinity percentages were greater in rabbits that were given LLLT. Crystallinity (41.14% to 54.57%) and the chemical composition of the bone at the distraction osteogenesis site were similar to the that of the control group (42.37% to 49.29%). The results showed that LLLT had a positive effect on the biomodulation of newly formed bone.
authors: School of Physics, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Caixa Postal 1429, 90619-900 Porto Alegre, RS, Brazil.
authors: Roberto
authors: R
authors: Hübler
authors: Eduardo
authors: E
authors: Blando
authors: Lêonilson
authors: L
authors: Gaião
authors: Paulo Eduardo
authors: PE
authors: Kreisner
authors: Letícia Kirst
authors: LK
authors: Post
authors: Cristina Braga
authors: CB
authors: Xavier
authors: Marília Gerhardt
authors: MG
authors: de Oliveira
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000528:radiation effects*; D001842:Bone and Bones / Q000737:chemistry / Q000528:radiation effects; D002118:Calcium / Q000032:analysis; D028022:Low-Level Light Therapy; D008297:Male; D010012:Osteogenesis / Q000528:radiation effects*; D019857:Osteogenesis, Distraction; D010758:Phosphorus / Q000032:analysis; D011817:Rabbits; D013052:Spectrometry, X-Ray Emission; D014961:X-Ray Diffraction
chemical_list: D010758:Phosphorus; D002118:Calcium