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

Abstract

Summary Objective: The aim was to compare osseointegration of blood perfused β-tricalcium phosphate cylinders (β-TCPB) with similar composites that were additionally loaded with cancellous bone and bone marrow (β-TCPB/BM/CB) for mandibular reconstruction. Methods: Twelve German Black-Headed sheep with an average weight of 72.5 ± 10 kg underwent segmental re-section of the right hemi-mandible. The animals that were assigned to group A (n=6) were reconstructed using β-TCPB while the sheep that were assigned to group B received β-TCPB/BM/CB grafts. Tissue quality was histologically assessed and bone-, scaffold-, cartilage- and fibrous-tissue area were estimated using semiautomated histomorphometrical software. Results: Composite grafts that were loaded with bone marrow and cancellous bone (β-TCPB/BM/CB) exhibited significant (p<0.01) higher amounts of bone formation than β-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 β-tricalcium phosphate composites may qualify as a promising alternative to autograft bone for mandibular reconstruction in human and veterinary medicine.