Effect of Tunnel Structure of β-TCP on Periodontal Repair in Class III Furcation Defects in Dogs

Background: The pore characteristics of bone graft materials play an important role in bone regeneration. Previous studies have reported that a pore size of 100 ~ 400 μm effectively induces vascular invasion and cell population within the materials. Many graft materials used recently have macropore (200 ~ 600 μm) or micropore (0.1 ~ 1 μm) structures. We devised a bone material with a tunnel pipe structure and pore size of 300 μm. The present study evaluated periodontal healing following implantation of this new bone graft material in furcation class III defects. Methods: Thirty mandibular premolar teeth of five beagles were used. After class III furcation defects were surgically created, each furcation was randomly treated with: 1) β-TCP with a tunnel pipe structure (tunnel group) (n=10); 2) Granular β-TCP (granular group) (n=10); and 3) No implant material (control group) (n=10). The dogs were sacrificed 8 weeks post-surgery and healing was evaluated histologically. Results: In the tunnel group, down growth of junctional epithelium was significantly less than that in the other two groups (P <0.01) and bone formation and blood capillary invasion were observed in the inner part of pores of the implanted material in the furcation. However, little bone formation was observed between the granules in the granular group. Conclusion: β- TCP with a tunnel pipe structure and pore size of 300 μm promotes bone regeneration and new cementum formation in class III furcation defects.