Reparo ósseo de ratos diabéticos. Efeito da laserterapia de baixa potência.

Abstract

The objective of this study was to evaluate the bone repair evolution of lesions in femurs of diabetic rats, submitted to low power laser therapy (LTBP). Twenty-four rats were divided into two groups: Normoglycemic (N) and Diabetic (D), with three analysis periods for each group: 3, 5 and 7 days. Group D animals were induced to diabetic mellitus by intravenous injection of streptozotocin (60mg / kg). Thirty days after induction, bone defects were created in the femurs of all animals. LTBP started immediately after the surgical procedure and was performed every 48 hours, only in the left femur. The right femur did not receive treatment, being considered a control group. The animals were sacrificed 3, 5 and 7 days after surgery. The femurs were removed and separated into four subgroups: Normoglycemic, Diabetic, Normoglycemic-LTBP and Diabetic-LTBP. Then, the femurs were fixed in 4% paraformaldehyde in 0.1M PBS, demineralized in EDTA and processed for embedded in paraffin. The 5 µm thick histological sections were stained with hematoxylin and eosin, and digitalized. Bone repair was assessed considering the filling of the lesion by newly formed bone tissue, presence of clot, granulation tissue, and bone trabeculae thickness. The Diabetic group showed a greater presence of residual clot, granulation tissue and less thick trabeculae, compared to the normoglycemic and Diabetic-LTBP groups, in the respective experimental periods. Bone repair in the Diabetic-Laser therapy group was apparently like the Normoglycemic group. The results showed that diabetes impaired the bone repair process and LTBP improved bone neoformation in diabetics.