Effectiveness Of The 904nm Laser Diode For Regeneration Of Bone Defects.

Acceleration of bone formation for repair of large bone defects is one of the great challenges in health science. Several studies are investigating mechanisms for bone repair on a quick and efficient manner and it is well known that the modulation of the immune/inflammatory responses play an important role for the bone tissue regeneration. This study was designed to evaluate the efficacy of 904nm Laser Diode in the bone tissue regeneration to repair a critical bone defect. Thirty male Wistar rats were separated into 3 groups of 10 animals each. Control rats were submitted to a circular bone defect with a 2 mm drill on the left tibia. A second group, submitted to the same bone defect as the controls, was irradiated daily with a 904nm laser diode, 60w 4J/cm2, from the first post-operatory day up to 14 days. A third group was irradiated with 904nm laser diode, 120w 4J/cm2 using the same protocol described for the second group. After 14 days, the bone defect was assessed by means of X-ray and bone densitometry. Animals were then anesthetized and perfused with 4% paraformaldehyde. The right and left tibias were removed and will be submitted to mechanical tests and histological analysis. The X-ray and bone densitometry results suggest that the 904nm laser diode is accelerating bone repair. The histological examination will help the understanding of the underlying mechanisms of this acceleration.