The aim of this study was to investigate the effect of the pore characteristics of β-tricalcium phosphate (β-TCP) on periodontal healing in class III furcation defects in dogs. Two types of β-TCP were prepared for grafting; 1) a tunnel pipe structure with an inner diameter of 300 μm, and 2) continuous pore structure with interconnected macropores. The furcations of thirty mandibular premolar teeth were implanted with each type of β-TCP or were left untreated as control. The dogs were sacrifi ced 8 weeks post-surgery, and healing was evaluated histologically. Downgrowth of junctional epithelium in the tunnel structure group was signifi cantly less than that in the other two groups (p<0.01). There was signifi cantly more new bone formation and new cementum formation in the tunnel structure group than that in the other two groups (p<0.01). These fi ndings suggested that β-TCP with a tunnel pipe structure promotes periodontal healing in class III furcation defects.