Vv. Viljanen et al., LOW-DOSAGE OF NATIVE ALLOGENEIC BONE MORPHOGENETIC PROTEIN IN REPAIR OF SHEEP CALVARIAL DEFECTS, International journal of oral and maxillofacial surgery, 26(5), 1997, pp. 389-393
A sheep skull trephine defect model was used to test the efficacy of a
llogeneic partially purified sheep bone morphogenetic protein (sBMP),
extracted using a low-cost alternative technique based on 60% ammonium
sulphate saturation of the guanethidine-HCI extract of pulverized bon
e matrix. Eight mg of partially purified sBMP was implanted in six 22-
mm right-side sheep calvarial critical-size defects trephined in the d
iploe area using a midline incision; left-side defects implanted with
an equal amount of type IV collagen served as controls. After 16 weeks
the sheep were killed and the defects removed. Formation of new bone
was evaluated using radiomorphometry and histomorphometry. The healing
percentage in sBMP-implanted defects was 60.8+/-8.1% and in controls
49.8+/-6.7% (P<0.05) as assessed by radiomorphometry. In cross-section
al histomorphometry, newly formed bone regenerated 50.9+/-15.1% in the
defects with sBMP and 16.1+/-10.6% in controls (P<0.01). The good res
ult, considering the low dosage of sBMP, can be explained by the stron
g osteoinductivity and low immunogenicity of native allogeneic sBMP.