Histological Comparison between Biphasic Calcium Phosphate and Deproteinized Bovine Bone on Critical-Size Bone Defects

Abstract The limited options for bone repair have led to an extensive research of the field and the development of alloplastic and xenogeneic grafts. The purpose of this study was to evaluate bone repair with two bone substitutes: deproteinized bovine bone (DBB) and biphasic calcium phosphate ceramic (BCP) in critical-size defect. A total of 8-mm defects were made in the parietal bones of rabbits (n=12). The animals were divided into three experimental groups: sham (defect filled with a blood clot), DBB (defect filled with DBB), and BCP (defect filled with BCP). After the experimental periods of 15 and 45 days, the animals were euthanized and submitted to histomorphometric analysis. The total defect area, mineralized tissue area, biomaterial area, and soft tissue area were evaluated. A greater amount of immature bone tissue and biomaterial particles were observed in the BCP group compared to DBB and sham at 45 days (p<0.05). There was no difference in the qualitative pattern of bone deposition between DBB and BCP. However, the sham group did not show osteoid islands along with the defect, presenting a greater amount of collagen fibers as well in relation to the DBB and BCP groups. There was a greater number of inflammatory cells in the DBB at 45 days compared to BCP and sham groups. In conclusion, BCP and DBB are options for optimizing the use of bone grafts for maxillofacial rehabilitation. Bone defects treated with BCP showed greater deposition of bone tissue at 45 days.

摘要 骨修复治疗的可选方案有限，推动了该领域的广泛研究以及同种异体移植与异种移植材料的研发。本研究旨在评估两种骨替代材料——脱蛋白牛骨（deproteinized bovine bone, DBB）和双相磷酸钙陶瓷（biphasic calcium phosphate ceramic, BCP）在临界尺寸骨缺损中的修复效果。研究在家兔顶骨制备共计8 mm的临界尺寸骨缺损（n=12），将实验动物分为三组：假手术组（缺损仅填充血凝块）、DBB组（缺损填充脱蛋白牛骨）与BCP组（缺损填充双相磷酸钙陶瓷）。分别于术后15天和45天处死实验动物，开展组织形态计量学分析，评估指标涵盖缺损总面积、矿化组织面积、生物材料面积及软组织面积。术后45天时，与DBB组和假手术组相比，BCP组可见更多未成熟骨组织与生物材料颗粒（p<0.05）。DBB组与BCP组的骨沉积定性模式无显著差异。但假手术组未观察到沿缺损分布的类骨岛，且其胶原纤维含量高于DBB组与BCP组。术后45天时，DBB组的炎症细胞数量多于BCP组与假手术组。综上，BCP与DBB均可作为优化颌面修复骨移植方案的可选材料。采用BCP治疗的骨缺损在术后45天展现出更优异的骨组织沉积效果。