ABSTRACT
BACKGROUND: There are various methods for management of allogeneic bone, xenogeneic bone and various tissue engineered materials, but there is no ideal method for treatment of insufficient bone mass following jaw defects. OBJECTIVE: To observe the repair efficiency of bone composite and biomembrane following large mandibular defect and mandibular defect combined with tooth luxation in animal studies. DESIGN, TIME AND SETTING: The controlled observational animal study was performed at the Animal Laboratory of Zhejiang University from March to July 2006. MATERIALS: The mixed proportion of Bio-oss material and autologous bone powder was 1:1. The proportion of recombinant human bone morphogenetic protein-2 freeze-dry powder dissolved in autologous fresh blood was 0.25 mg:1 mL. Bone powder mixture was moistened by blood containing human bone morphogenetic protein to stick on the medicine spoon for moulding easily. METHODS: Ten New Zealand rabbits were selected. Consecutive bone defects (15 mm×6 mm×5 mm) were made in the inferior border of bilateral mandible body. Bone composite and Bio-gide membrane were randomly implanted into one side (bone composite + Bio-gide membrane group). Another side was directly sutured as blank control group. The remaining 30 rabbits were considered bone composite + Bio-gide membrane + implantation tooth group. A bone defect (15 mm×6 mm×8 mm) was made at the upper site of inferior border of mandible, with the combination of tooth luxation. Bone composite and Bio-gide membrane were implanted, and the luxation teeth were implanted into the original site. MAIN OUTCOME MEASURES: Implantation site, composite conjugation, loose of bone formation and implanted teeth were generally observed. New bone formation at the bone defect site was observed using radiograph and histological method. RESULTS: At 12 weeks following surgery, a bone defect, which was smaller than the original bone, was found at the mandibular defect site in the blank control group. New bones were visible in the mandibular defect site in the bone composite + Bio-gide membrane group. Radiograph demonstrated that the density of defect bone site was similar to normal bone tissue. Histological method revealed that bone implant formed board-shaped bone. No significant loose was detected in implanted teeth of 17 rabbits in the bone composite + Bio-gide membrane + implantation tooth group. Radiograph demonstrated that no transparent area was found in the root tip of 13 rabbits. Histological method showed replacement resorption in 13 rabbits. CONCLUSION: Bone composite combined with Bio-gide membrane for repairing large mandibular defect obtained good efficiency. The outcome of autologous tooth implantation is acceptable in the near future.