History and Objectives: Due to discrepancies on the effect of low power Helium-Neon laser on healing of bone fracture, the present study intends to investigate such effect on healing of bone deformation of rabbit tibia.

Materials and Methods: An experimental study on 39 albino rabbits was carried out. They were randomly divided into control and experimental groups. Under aseptic condition and using anesthesia, an incision was made on skin with deep fascia on the internal surface of tibia bone on the left side of the animal. With an electric drill (2mm), a small deformation or hole was created on this surface. The day of surgery was considered as zero day and animals were divided into 3 groups of 14, 21 and 28 days. A low power laser, 1.2 J/cm², was applied daily once every day. Animals were killed and the left tibia bone was removed. Biomechanic studies were performed on the bones. The degree of fragility was determined by using 3 point bending of the bones. The absorbed energy at the point of fracture and the extent of bone deformation and elastic stability was measured.

Results: The extent of elastic stability and absorbed energy was significant in 21st and 28th day of experimental group respectively (P<0.05). Augmentation of biomechanic specificities was observed in the 3 experimental groups and differences were significant for day 14-28 and 21-28.

Conclusion: Laser radiation with low power Helium-Neon with energy density of 1.2 J/cm² is performed according to the procedure in the present study increases the speed of bone healing at the site of tibia bone deformation.