Effects of Low-Level Helium-Neon Laser Therapy on Healing of Partial Thickness Defect of Experimental Induced Diabetic Rats

Purpose: The aim of present study was to study the effects of low-level helium–neon laser irradiation on biomechanical properties of tibiae partial bone defect in streptozotocin–diabetic rat. Materials and Methods: Twenty male rats were used .Diabetes was induced in rats by one time intraperitoneal injection of 60 mg/kg streptozotocin .After one month ,under sterile conditions and general anesthesia one partial bone defect were made in mid portion of right tibia of rats .Rats were divided into control and no 1 and no 2 experimental groups . Rats of no 1 and 2 experimental groups were received he-ne laser with 2.1 J/cm² and 11.6 J/cm² energy densities three times a week for six weeks. After that rats were killed and their tibiae were extracted and were examined by three point bending biomechanical test. Data were analysed by ANOVA and expressed as mean±SEM. Results: The energy absorption (N/mm) of no1 experimental group. Control and no2 experimental groups were 52±45, 44.2±35.2 and 36.3±20.1 respectively. Load at break (Nmm) of no1 and no2 experimental group and control group were 34.2±13.2, 32.6±18.6 and 31.8±27.4 respectively .Maximum force per square mm of no1 experimental group, control and no2 experimental group were 8.2±3.57, 8.2±4.4 and 7±4.96 respectively .There were not significant differences between all above mentioned parameters and also elastic stiffness, maximum force and bone surface area of groups. Conclusion: He-Ne laser irradiation on tibias of partial bone defect in streptozotocin diabetic rats did not cause positive effects on fracture healing from biomechanical evaluation point of view.