PURPOSE: To investigate the effect of low-level laser therapy on bone healing in diabetic rats. METHODS: Bone cavities (19 mm diameter) were performed in the femur of 72 alloxan-induced diabetic rats, which were assigned into four groups: CTR (non-diabetic control), DBT (diabetic) CTRL (non-diabetic irradiated) and DBTL (diabetic irradiated). Low-level laser therapy was performed every 48h for seven days. Animals were euthanized at seven, 18 and 30 days. Alkaline phosphatase serum levels and bone repair were analyzed. RESULTS: Low-level laser therapy significantly increased alkaline phosphatase in at seven and 18 days (p<0.001), and improved bone healing at seven (p<0.01), 18 (p<0.05) and 30 (p<0.01) in diabetic animals. In addition, bone healing in irradiated diabetic group was statistically similar to control group at 30 days (p>0.05). CONCLUSION: Low-level laser therapy increased the serum levels of alkaline phosphatase and improved bone healing in alloxan-induced diabetic rats.

PURPOSE:To assess the evolution profile of the immunohistochemical expression of stromal constituents over the time-course of wound healing in a murine model.METHODS: Surgical wounds were performed in the back of 24 Wistar rats. After three, seven, 14 and 21 days, six rats were euthanized and the wounded histologically processed to assess the immunohistochemical expression of CD3, CD20, CD31, α-SMA and type-I collagen. Non-injured skin samples (NSS) were used as control. Data were subjected to statistical analysis using ANOVA and Tukey test.RESULTS: The mean of CD3 and CD20 positive cells in the wounds was significantly higher than in NSS at seven and 14 days (p<0.001). The blood vessels content was significantly lower than in NSS (p<0.05) at three days, but increased at seven and 14 days (p<0.01). The mean of α-SMA positive cells at seven, 14 and 21 days was higher than in NSS (p<0.05). The relative content of type I collagen increased from three to 21 days, but remained lower than in NSS (p<0.05).CONCLUSIONS:Lymphoid cells, myofibroblasts and microvessels contents varied over the time-course of wound healing, with peak at seven days and progressive reduction until 21 days. The type I collagen content increased over time.