Comparison of two beta-tricalcium phosphate composite grafts used for reconstruction of mandibular critical size bone defects

Objective: The aim was to compare osseointegration of blood perfused beta-tricalcium phosphate cylinders (beta-TCPB) with similar composites that were additionally loaded with concellous bone and bone marrow (beta-TCPB/BM/CB) for mandibular reconstruction. Methods: Twelve German Black-Headed sheep with an average weight of 72.5 +/- 10 kg underwent segmental resection of the right hemi-mandible. The animals that were assigned to group A (n = 6) were reconstructed using beta-TCPB while the sheep that were assigned to group B received beta-TCPB/BWCB grafts. Tissue quality was histologically assessed and bone-, scaffold-, cortilage- and fibrous-tissue area were estimated using semioutomated histomorphometrical software. Results; Composite grafts that were loaded with bone marrow and concellous bone (beta-TCPB/BWCB) exhibited significant (p<0.01) higher amounts of bone formation than beta-TCPB. The patients that were assigned to group B achieved defect union and a high grade of bone maturation. Residual ceramic remnants were rare and disconnected. Bone maturity within group A was inferior and none of the specimens showed defect union. The defect centre was still occupied by a ceramic core. Clinical significance: Bone and bone marrow augmented beta-tricalcium phosphate composites may qualify as a promising alternative to autograft bone for mandibular reconstruction in human and veterinary medicine.