Effects of low-level laser therapy (LLLT) on bone repair in rats: optical densitometry analysis.
The aim of this study was to evaluate the process of bone repair in rats submitted to low-level laser therapy using optical densitometry. A total of 45 rats which underwent femoral osteotomy were randomly distributed into three groups: control (group I) and laser-treated groups using wavelengths in the red (λ, 660-690 nm) and in the infrared (λ, 790-830 nm) spectra (group II and group III, respectively). The animals (five per group) were killed after 7, 14, and 21 days and the femurs were removed for optical densitometry analysis. Optical density showed a significant increase in the degree of mineralization (gray level) in both groups treated with the laser after 7 days. After 14 days, only the group treated with laser therapy in the infrared spectrum showed higher bone density. No differences were observed between groups after 21 days. Such results suggest the positive effect of low-level laser therapy in bone repair is time- and wavelength-dependent. In addition, our results have confirmed that optical densitometry technique can measure bone mineralization status.
Instituto de Engenharia Biomédica, Universidade Camilo Castelo Branco, UNICASTELO, Rodovia BR-116, 12247-004, São José dos Campos, São Paulo, Brazil.
Danillo
D
Barbosa
Renato Aparecido
RA
de Souza
Murilo
M
Xavier
Fabiano Fernandes
FF
da Silva
Emilia Angela Loschiavo
EA
Arisawa
Antonio Guillermo Jose Balbin
AG
Villaverde
D000818:Animals; D001861:Bone Regeneration / Q000528:radiation effects*; D002113:Calcification, Physiologic / Q000528:radiation effects; D003720:Densitometry / Q000379:methods*; D005269:Femur / Q000601:surgery; D007259:Infrared Rays; D028022:Low-Level Light Therapy / Q000379:methods*; D008297:Male; D010027:Osteotomy; D051381:Rats; D017208:Rats, Wistar