RESUMO
This study aimed to evaluate the effect of infrared laser (IRL) on bone repair in ovariectomized rats subjected to femoral osteotomies. Of 32 rats, half underwent bilateral ovariectomy (OVX) and the other half underwent sham ovariectomy (SHAM). A period of 3 months was defined to observe the presence of osteoporosis. The rats were subjected to osteotomies in the femurs and then fixed with a miniplate and 1.5-mm system screws. Thereafter, half of the rats from both SHAM and OVX groups were not irradiated, and the other half were irradiated by IRL using the following parameters: wavelength, 808 nm; power, 100 mW; 60 s for each point; 6 J/point; and a total of 5 points of bone gap. All animals were euthanized 60 days after surgery. The femur gap was scanned using micro-computed tomography (micro-CT). The samples were then examined under a confocal laser microscope to determine the amounts of calcein and alizarin red. The slides were stained with alizarin red and Stevenel's blue for histometric analysis. In the micro-CT analysis, the OVX groups had the lowest bone volume (P < 0.05). When the laser was applied to the OVX groups, bone turnover increased (P < 0.05). New bone formation (NBF) was comparable between SHAM and OVX/IR (P > 0.05) groups; however, it was less in the OVX groups (P < 0.05). In conclusion, the results encourage the use of IRL intraoperatively as it optimizes bone repair, mainly in animals with low bone mineral density.
Assuntos
Osteoporose , Feminino , Ratos , Animais , Humanos , Microtomografia por Raio-X , Fêmur/diagnóstico por imagem , Fêmur/cirurgia , Osteotomia , Ovariectomia/efeitos adversos , Densidade ÓsseaRESUMO
This in vivo study investigated whether the bioactivity of anodizing coating, produced by plasma electrolytic oxidation (PEO), on mini-plate in femur fracture could be improved with the association of photobiomodulation (PBM) therapy. From the 20 ovariectomized Wistar female rats, 8 were used for model characterization, and the remaining 12 were divided into four groups according to the use of PBM therapy by diode laser (808 nm; power: 100 mW; energy: 6.0 J; energy density: 212 J/cm2; power density: 3.5 W/cm2) and the type of mini-plate surface (commercially pure titanium mini-plate -cpTi- and PEO-treated mini-plate) as follow: cpTi; PEO; cpTi/PBM; and PEO/PBM. After 60 days of surgery, fracture healing underwent microstructural, bone turnover, histometric, and histologic adjacent muscle analysis. Animals of groups with PEO and PBM showed greater fracture healing than cpTi control group under histometric and microstructural analysis (P < 0.05); however, bone turnover was just improved in PBM's groups (P < 0.05). there was no difference between cpTi and PEO without PBM (P > 0.05). Adjacent muscle analysis showed no metallic particles or muscle alterations in all groups. PEO and PBM are effective strategies for bone repair in fractures, however their association does not provide additional advantages.