A comparison of the bone regeneration and soft-tissue-formation capabilities of various injectable-grafting materials in a rabbit calvarial defect model.

Restoring adequate blood supply is essential to the success of bone repair and augmentation procedures in craniofacial surgery. Nevertheless, the manner by which the incorporation of collagen gels (which can potentially induce angiogenesis), particulated deproteinized bovine bone grafts, or a combination of both can accelerate or delay bone regeneration in a clinical setting remains controversial. The objective of this study was to evaluate radiographically and histologically the capacity and functionality of particulated bone grafts and collagen gels on bone ossification and soft tissue formation in a rabbit calvarial defect. Bilateral calvarial defects in adult white New Zealand rabbits were filled or left either unfilled with bone grafts (DBBM), collagen gels (Gel), or a combination of both (DBBM + Gel). The defects were allowed to heal for 1, 2, and 6 months postoperatively before termination. Healing and regeneration patterns were assessed by 3D µCT and histological methods, and the biomechanical properties of regenerated tissue constructs were investigated and compared with autogenous calvarial bone. Results show that implanted DBBM and DBBM + Gel significantly enhanced immature bone formation compared with the empty and Gel groups; the latter treatment improved soft tissue formation and impeded immature bone formation but yielded no significant effect on mature bone formation. Implantation of DBBM not only effectively reconstructed 188.83 ± 25.25% of the tissue volume of the original defect, but it also regenerated bone tissue with similar tissue composition and biomechanical properties as the original autogenous bone. We also show that implanting different biomaterials can control the composition of soft and hard tissue in reconstructed tissue constructs in calvarial bone defects. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 529-544, 2019.