Department of Periodontology, State University of Rio de Janeiro, Boulevard 28 de Setembro, 157 - 2º andar - sala 10, Rio de Janeiro, RJ, CEP 20551-030, Brazil.
Department of Orthopedics, University of Miami, Miami, FL, USA.
Sci Rep. 2023 Jan 25;13(1):1422. doi: 10.1038/s41598-023-28170-6.
Lack of bone volume to place dental implants is frequently a problem in the reconstruction of edentulous patients. Even though autografts are the gold standard for jaw regeneration, morbidity associated with the harvesting site stimulates the demand for other substitutes. The aim of this study is to characterize the incorporation and the osteogenic ability of a viable cryopreserved human bone graft (VC-HBG) in the mandibular augmentation in rats. Bone chips from fresh human vertebrae cadaveric donors were processed, cryoprotected and deep-frozen at - 80 °C maintaining its cell viability. A jaw augmentation model was used in 20 athymic nude rats allocated into 2 groups to either receive the VC-HBG or an acellular graft as control (A-HBG). The assessment of the grafts' incorporation was performed at 4 and 8 weeks by micro-CT, histomorphometry and immunohistochemistry. Bone volume gain was significantly higher for the VC-HBG group at both time points. At 4 weeks, the A-HBG group presented significantly higher mineral density, but at 8 weeks, the VC-HBG group showed significantly higher values than the A-HBG. There was no statistical difference between VC-HBG and A-HBG groups at 4-weeks for remaining graft particles, while at 8 weeks, the VC-HBG group showed significantly less graft remnants. Collagen I, osteopontin and tartrate-resistant acid phosphatase expression were significantly higher in the VC-HBG group at both time points, while osteocalcin expression was significantly higher in the VC-HBG group at 8-weeks compared to the A-HBG group. This experimental research demonstrated that the VC-HBG shows positive osteogenic properties, greater bone formation, higher rate of bone remodeling and a better overall incorporation in rats' mandibles compared to the A-HBG.
在无牙颌患者的重建中，缺乏用于植入牙种植体的骨量通常是一个问题。尽管自体移植物是颌骨再生的金标准，但与采集部位相关的发病率刺激了对其他替代品的需求。本研究旨在描述在大鼠下颌骨增量中可生物利用的冷冻保存人骨移植物（VC-HBG）的整合和成骨能力。从新鲜的人尸体捐赠者的椎骨中获取骨屑，经过处理、冷冻保护并在-80°C 下深冻，以保持其细胞活力。在 20 只无胸腺裸鼠中建立了颌骨增量模型，将其分为接受 VC-HBG 或无细胞移植物（A-HBG）作为对照的两组。通过 micro-CT、组织形态计量学和免疫组织化学评估移植物的整合情况，分别在 4 周和 8 周时进行。在两个时间点，VC-HBG 组的骨体积增加均显著更高。在 4 周时，A-HBG 组的矿物质密度显著更高，但在 8 周时，VC-HBG 组的矿物质密度显著高于 A-HBG 组。在 4 周时，VC-HBG 组和 A-HBG 组之间的剩余移植物颗粒没有统计学差异，而在 8 周时，VC-HBG 组的移植物残余物明显较少。在两个时间点，VC-HBG 组的 I 型胶原、骨桥蛋白和抗酒石酸酸性磷酸酶的表达均显著更高，而在 8 周时，VC-HBG 组的骨钙素表达显著高于 A-HBG 组。这项实验研究表明，与 A-HBG 相比，VC-HBG 在大鼠下颌骨中具有阳性成骨特性、更高的骨形成率、更高的骨重塑率和更好的整体整合。
