Fig. (5) Histological findings in furcation defect at 10 days for control group. (A) Slight alveolar bone formation was observed on the bottom of the defect. (B) Higher magnification image of the framed area (1) in (A). Invasion of epithelial tissue was detected. (C) Higher magnification image of the framed area (2) in (A). Inflammatory granulation tissue was frequently observed at the furcation area. CT, connective tissue; PB, preexisting bone; NB, new bone; EP, epithelial tissue; IT, inflammatory granulation tissue; R, root; arrowheads, apical notches. Staining: hematoxylin and eosin. (Scale bars represent 1 mm (A) and 100 µm (B, C)).