Bone remodeling is under the control of various signals and systems in the body, including the nervous system. Semaphorin (Sema) 3A is a chemorepellent protein which regulates bone mass. Schwann cells, having a pivotal role following nerve injury, interact with Sema3A under numerous circumstances. The present study established a co‑culture system of MG63 and Schwann cells to investigate the role of the interaction between Sema3A and Schwann cells in osteogenesis. The results from the alkaline phosphatase assay, calcium nodule staining and the analysis of the osteogenic gene expression revealed that Sema3A inhibits osteogenic differentiation of MG63 cells in single‑cell culture and promotes osteogenic differentiation of MG63 cells in co‑culture with Schwann cells, in a concentration‑dependent manner. These findings suggest that the presence of Schwann cells induces Sema3A‑associated osteogenic differentiation in bone cells, and also reveals the pivotal role of Sema3A as a regulator in the skeletal and nervous systems, thus contributing to a better understanding of the interaction between these systems.

The objective of this study was to compare the ability of platelet-rich fibrin (PRF), Bio-Oss and osteoid hydroxyapatite (OHA) in early bone formation by filling tooth extraction sockets in rabbits. 48 rabbits were randomly divided into 4 groups: group A (PRF), group B (Bio-Oss), group C (OHA), and group D (control). One of the mandibular central incisors was extracted and instantly filled with graft materials. General, radiological and histological observations were evaluated 1, 2, 3, 4, 6, and 8 weeks later. In the first 4 weeks, the quantity of new bone in the PRF group alveolar defects was the best, and the bone mineral density was significantly higher. At the 6 th and 8 th weeks, the speed of new bone formation in the Bio-Oss group and the OHA group was better than that in the PRF group. Compared with the Bio-Oss group, the OHA group had osteoblasts which were more active and a slightly larger number of bone trabeculae. In addition, the control group was worse than other groups in bone-formation. These results indicate that PRF, OHA and Bio-Oss all can promote osteogenesis in tooth extraction sockets, but the effect of PRF is remarkable at the early time of bone formation. At the later stage, both Bio-Oss and OHA can repair bone defects and guide bone regeneration, and the potential bone formation ability of OHA is better.