Low-Power-Laser and Synthetic Hydroxyapatite on the Bone Healing in Rats

Objectives: The objective of this work is to evaluate the healing of bone defects (3mm3) in femur of Wistar albinus rats, submitted to Low Power Laser Therapy - LPLT (GaAlAs, λ830nm, 40mW, CW, ø~0,6mm, DMC Equipamentos, São Carlos, SP, Brazil) and synthetic hydroxyapatite implants Gen-phos® (Genius - Baumer S.A, Mogi Mirim, SP, Brazil). Method: the sample was divided in 03 Groups: Group I (control – n=9); Group II (Experimental Gen-phos® - n=12); Group III (Experimental LPLT – n=12). The irradiated group, it received seven irradiations at every 48 hours, being immediately the first after the surgical procedure. The used dosimetry was of 16J/sessão, divided in four points of 4J (142,5J/cm²) around the bone defect. The sacrifice period was of 15, 21 and 30 days after the surgery. After laboratorial procedure of routine, the removed bone pieces were stained with H&E and Picrosírius stains, and examined under Light Microscopy. Results: The results has showed that, in both experimental groups, it was observed a best and faster bone repair, evidenced by the largest bone new formation into the cavity and in the cortical defect, and larger proliferation of collagen fibers specially in the irradiated group. Acting for different mechanisms, both variables tested stimulated the bone repair in the bone defects starting from the 15th day. Conclusion: It is concluded that both Low Power Laser Therapy and synthetic hydroxyapatite implants, produced a biostimulation effect on the healing of bone defects.