Yang Jingwen, Kang Yunqing, Browne Christopher, Jiang Ting, Yang Yunzhi
From the *Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China; †Department of Orthopedic Surgery, Stanford University, Stanford, California; and ‡Department of Materials Science and Engineering, Stanford University, Stanford, California.
J Craniofac Surg. 2015 Mar;26(2):e148-53. doi: 10.1097/SCS.0000000000001383.
Bone augmentation requires scaffold to promote forming of natural bone structure. Currently, most of the reported bone scaffolds are porous solids with uniform pores. The aim of the current study is to evaluate the effect of a graded porous β-tricalcium phosphate scaffolds on alveolar bone augmentation. Three groups of scaffolds were fabricated by a template-casting method: (1) graded porous scaffolds with large pores in the center and small pores at the periphery, (2) scaffolds with large uniform pores, and (3) scaffolds with small uniform pores. Bone augmentation on rabbit mandible was investigated by microcomputed tomography, sequential fluorescent labeling, and histologic examination 3 months after implantation.The result presents that all the scaffold groups maintain their augmented bone height after 3-month observation, whereas the autografting group presents an obvious bone resorption. Microcomputed tomography reveals that the graded porous group has significantly greater volume of new bone (P < 0.05) and similar bone density compared with the uniform pores groups. Bone substance distributes unevenly in all the 3 experimental groups. Greater bone volume can be observed in the area closer to the bone bed. The sequential fluorescent labeling observation reveals robust bone regeneration in the first month and faster bone growth in the graded porous scaffold group than that in the large porous scaffold group. Histologic examinations confirm bone structure in the aspect of distribution, activity, and maturity. We conclude that graded porous designed biodegradable β-tricalcium phosphate scaffolds are beneficial to promote bone augmentation in the aspect of bone volume.
骨增量需要支架来促进天然骨结构的形成。目前，大多数报道的骨支架是具有均匀孔隙的多孔固体。本研究的目的是评估梯度多孔β-磷酸三钙支架对牙槽骨增量的影响。通过模板铸造法制备了三组支架：（1）中心为大孔、周边为小孔的梯度多孔支架，（2）具有大的均匀孔隙的支架，（3）具有小的均匀孔隙的支架。植入3个月后，通过微型计算机断层扫描、连续荧光标记和组织学检查对兔下颌骨的骨增量进行了研究。结果显示，在3个月的观察期后，所有支架组均保持了其增加的骨高度，而自体骨移植组则出现了明显的骨吸收。微型计算机断层扫描显示，与均匀孔隙组相比，梯度多孔组的新骨体积显著更大（P < 0.05），且骨密度相似。在所有3个实验组中，骨质分布不均匀。在靠近骨床的区域可观察到更大的骨体积。连续荧光标记观察显示，在第一个月骨再生强劲，且梯度多孔支架组的骨生长速度比大孔支架组更快。组织学检查从分布、活性和成熟度方面证实了骨结构。我们得出结论，梯度多孔设计的可生物降解β-磷酸三钙支架在骨体积方面有利于促进骨增量。
