The effects of large piece xenogeneic bone which was
separated from healthy pigs as a scaffold on repair of mandibular defect was
investigated and the applicability of antigen-extracted xenogeneic cancellous
bone (AXCB) soaked with rhBMP-2 in bone defect repair was assessed. Mandibular
defects were created in 48 New Zealand Rabbits, and then randomly divided into
4 groups, which was grafted in the mandibular defects with AXCB, AXCB soaked
with rhBMP-2, autograft bone, or blank. Equal number of animals from each group
was classified into three time points (4, 8, and 12 weeks) after operation for
gross pathological observation, hematoxylin and eosin (H & E) staining,
radiographic examination, and bone density measurement. H & E staining
revealed that the area percentage of bone regeneration in the group of
AXCB/rhBMP-2 graft was 27.72 ± 4.68, 53.90 ± 21.92,
and 77.35 ± 9.83 when at 4, 8, and 12 weeks, which was better than that of auto
bone graft, prompting that the group of AXCB/rhBMP-2 graft had commendable
osteogenic effect. And comparing with the AXCB without rhBMP-2, of which the
area percentage of bone regeneration was only 14.03 ± 5.02,
28.49 ± 11.35, and 53.90 ± 21.92, the osteogenic effect of AXCB/rhBMP-2
graft was demonstrated to be much better. In the group of AXCB/rhBMP-2 graft, the
area percentage of bone regeneration increased, and the implanted materials
were gradually degraded and replaced by autogenous bone regeneration over time.
We concluded that antigen-extracted xenogeneic cancellous bone (AXCB)
graft soaked with rhBMP-2 had shown excellent osteogenic effect in repair of
bone defects, with good biocompability.