Influence of the λ780 nm laser light on the repair of surgical bone defects grafted or not with biphasic synthetic micro-granular hydroxylapatite + Beta-Calcium triphosphate

The treatment of bone loss due to different etiologic factors is difficult and many techniques aim to improve repair, including a wide range of biomaterials and, recently, photobioengineering. This work aimed to assess, through histological analysis The aim of this study was to assess, by light microscopy, the repair of bone defects grafted or not with biphasic synthetic micro-granular Calcium hydroxyapatite (HA) + Beta-TCP associated or not with Laser phototherapy – LPT (λ780 nm). Forty rats were divided into 4 groups each subdivided into 2 subgroups according to the time of sacrifice (15 and 30 days). Surgical bone defects were made on femur of each animal with a trephine drill. On animals of Clot group the defect was filled only by blood clot, on Laser group the defect filled with the clot was further irradiated. On animals of Biomaterial and Laser + Biomaterial groups the defect was filled by biomaterial and the last one was further irradiated (λ780 nm, 70 mW, spot size ∼ 0.4 cm2, 20 J/cm2-session, 140 J/cm2-treatment) in four points around the defect at 48-h intervals and repeated for 2 weeks. At both 15th and 30th days following sacrifice, samples were taken and analyzed by light microscopy. Many similarities were observed histologically between groups on regards bone reabsorption and neoformation, inflammatory infiltrate and collagen deposition. The criterion degree of maturation, marked by the presence of basophilic lines, indicated that the use of LPT associated with HA + Beta TCP graft, resulted in more advanced stage of bone repair at the end of the experiment.