An experimental study of the wound healing after irradiation

The decalcified freeze-dried homogeneous bone grafts in the irradiated rabbit mandible

Abstract

The author performed the following examination to investigate the effect of decalcified freeze-dried homogeneous bone grafts on the irradiated rabbit mandible.
Group I: no-irradiation, bone defect only
Group II: no-irradiation, decalcified freeze-dried homogeneous bone grafts into bone defect
Gruop III: after irradiation, bone defect only
Group IV: after irradiation, decalcified freeze-dried homogeneous bone grafts into bone defect
Each defect measured 6×3×5mm was made in the inferior border of the rabbit mandible.In Group III and IV, bone defects were made 4 weeks after 36 Gy irradiation. Decalcified freeze-dried homogeneous bones were prepared in the manner described by Urist, et al. and then the crushed bone fragments were implanted into the bone defects. The rabbits were killed at 1, 2, 4, and 12 weeks postoperatively. Observation was done using H-E stain sections, labelling and microradiography.
Group I showed more rapid new bone formation in the bone defects than Group II at 1 and 2 weeks postoperatively, but at 4 and 12 weeks new cortical bones were formed and there was little difference in the healing between Group I and II. In Group III and Di, new bone formation was almost never seen at 1 and 2 weeks. Group III showed thin cortical bone formation which carved into the bone marrow side, but Group IV showed the original shape and thickness of the inferior border at 12 weeks. The author thought that these results suggested the effect of the decalcified freeze-dried homogeneous bone grafts on the irradiated bones.