Abstract
The purpose of this study was to elucidate the characterization of new bone formation following guided bone regeneration (GBR). Twenty-four adult mongrel dogs were used. The first, second, third and fourth premolars in the mandibular of each dog were extracted. Four months after tooth extraction, a buccal-dehiscence defect was surgi-cally made on each edentulous area. On the experi-mental side, each defect was covered with an expanded polytetrafluoroethylene (e-PTFE) mem-brane, and the membrane was secured by mini-screws and cyanoacrylate. On the control side, no membrane was placed over the defects. Animals were sacrificed at 1, 2, 4, 8 and 16 weeks postoper-atively. Histological observations and histomor-phometric analyses were performed on each section. Histological observations were performed by hematoxylin & eosin double stain, and the localiza-tion of alkaline phosphatase (ALP) by Azo-dye method was assessed. After 2 weeks, on the con-trol side ALP activity was localized at the bottom of the defect. On the experimental side, ALP activ-ity was observed across the entire defect beneath the e-PTFE membrane. Moderate ALP activity was observed in granulation tissue including spindle -shaped cells and surrounding bone trabecula. After 4 weeks, relative osteoid volume (ROV) and fractional formation surface ratio (FrFSR) were significantly larger in the experimental side than in the control side (p<0.05). After 4, 8 and 16 weeks, bone formation volume was significantly greater in the experimental side than in the control side (p< 0.05). These results suggest that the e-PTFE membrane used in the GBR can create and sustain sufficient space for bone formation and allow the new bone to mature.
