Effects of Biosilicate® Scaffolds and Low-Level Laser Therapy on the Process of Bone Healing

Objective: This study aimed to investigate the in vivo tissue performance of the association of Biosilicate ® scaffolds and low-level laser therapy (LLLT) in a tibial bone defects model in rats. Background data: Many studies have been demonstrating the osteogenic potential of Biosilicate and LLLT. However, there is a need to investigate the effects of both treatments for bone consolidation. Methods: The animals were divided into control group (CG), Biosilicate scaffold group (BG), and Biosilicate scaffolds plus LLLT group (BLG). Animals were euthanized after 15, 30, and 45 days post-injury. Results: The histological analysis revealed that all the experimental groups showed inflammatory infiltrate and granulation tissue, at the area of the defect at day 15. After 30 days, CG still showed granulation tissue and bone ingrowth. Both Biosilicate groups presented newly formed bone and interconected trabeculae. At 45 days, CG showed immature newly formed bone. A more mature newly formed bone was observed in BG and BLG. On day 15, BG demonstrated a statistically higher expression of cyclooxygenase (COX)-2 compared with CG and BLG. No statistically significant difference was observed in COX-2 immunoexpression among the groups at 30 and 45 days. Similar expression of bone morphogenetic protein (BMP)-9 was demonstrated for all experimental groups at 15 and 30 days. At 45 days, the BMP-9 immunoexpression was statistically upregulated in the BLG compared with the CG and BG. No statistically significant difference was observed in the receptor activator of nuclear factor kappa-B ligand (RANKL) immunoexpression among the groups in all periods evaluated. Biosilicate groups presented a decrease in biomechanical properties compared with CG at 30 and 45 days post-surgery. Conclusions: Our findings suggest that Biosilicate presented osteogenic activity, accelerating bone repair. However, laser therapy was not able to enhance the bioactive properties of the Biosilicate.