Optimal Diameter of Honeycomb Tunnel Structure induces Bone Regeneration and Metabolism by Promoting Angiogenesis for an Implant Circumference Bone Defect

To develop an effective method of bone augmentation for dental implants, particularly for patients with a scarce amount of bone, we introduced a new honeycomb-like beta-tricalcium phosphate (H-beta-TCP) as a scaffold, whose unique geometrical properties induce bone formation along with vasculature. A total of six beagles from 6 to 7 years old were used for this study. Autologous bone marrow-derived mesenchymal cells (BMC) cultured with H-beta-TCP were implanted around the dental implants, and healing was compared with conventional bone augmentation using autogenous bone. The 2-wall pen-implant defects were filled with the scaffold material pre-coated with BMP-2 and cultured with BMCs. Judging from the surface contact area between the bone and the implant, at 12 weeks the highest bone formation was found in the experimental group using the BMP-2 coated H-beta-TCP with BMCs. This was significantly higher than the control H-beta-TCP with BMP-2-coating but without BMC. It was noted that within the tunnels of the implanted H-beta-TCP, one or two blood vessels with a diameter of 50-100 micro meter were generated in most cases after 2 weeks. These results suggested that the geometry of the honeycomb like beta-TCP with, gave advantages in terms of initial induction of blood vessel formation which is essential for bone augmentation.