مطالعه بافت شناسی آثار تابش کم توان هلیوم نئون بر التیام نقص استخوانی جزیی در استخوان تی بیای خرگوش

Background and purpose: During present research the effects of low power helium-neon laser rediation on rabbit’s tibia after partial ostetomy were studied by quantitively histological methods. Materials and Methods: The type of the research was experimental. 42 male adult rabbits randomly divided into experimental (ex) and control (co) groups. Ëach group divided into 3 equall sub groups. Ünder general anesthesia and sterile conditions one incision were made on the soft tissue of medial aspects of the left tibia and then one small circular defect was made in the shaft of the tibia (partial osteotomy). The depth of defect was reached the central the chanal of bone. The day of surgery was day zero and next day was day one and etc ... . Ïn the ex group from day zero until 14th day at subgroup one and until 21th day at subgroup two and unril 28th day at subgroup three low power helium neon laser was irradiated on the defect by Grid technique. Ënergy density of the laser was 1.2. Ât the end of the above mentioned periods, rabbits were killed by ether and one sample were obtained from obtained from the defect. The samle fixed and decalcified and processed and embedded in parafin and sections were obtained from the block. Sections were stained by Hematoxyline and Ëosin method and masson’s trichrome method. Sections were studied histologically by 2 following mthods: 1- Graded descriptively evaluation method. 2- Quantitative method. When sections were studied by the first method , according to the quality of maturation of the callus , they were graded from zero until 8. When section by the second method the depth of newly periosteum and callus were calculated by a special eyepiece. Tow groups were compared with each other by ann Whitney Ü test method. Results: Results of graded descriptively evaluation method of ex. group were lower than co. group at 14th day and were equall at 21 th day and were higher at 28th day but non of this differences weren’t significant. Results of quantitative method of ex. Group were better than co. group and differences of increased depth of newly formed periosteum at 21th day were significant (P<0.05). Çonclusion: Low power helium-neon laser radiation on partial osteotomy of rabbit’s tibia were increased significantly the depth of newly formed periosteum and total depth of newly formed periosteum and callus at 21th day and results of graded descriptively evaluation method at 28th day were higher than control group.