Chang R C, Kao A S
Oral & Maxillofacial Surgery, Department of Dentistry, Veterans General Hospital-Taipei and Dental College, National Yang-Ming University, Taiwan.
Int J Oral Maxillofac Surg. 2000 Feb;29(1):54-61.
The purpose of this study was to investigate the biomechanical behavior and the histology of particulate hydroxylapatite (HA) implanted in bone defects created in femurs of 48 adult mongrel dogs. The bone defects, measuring 10 x 10 x 25 mm with or without HA implantation, were allowed to heal until the end of the 1st, 2nd, 3rd, 6th, 9th and 12th months after surgery. The harvested tissue specimens from the implant sites were processed into long cubic or rectangular prismatic forms. Their mechanical strengths were assessed using compression and shearing tests to measure the maximal compressive and shear stress by force loading on the middle portions of the specimens. Histological sections of each stage were processed with both decalcified and nondecalcified methods. The results showed that the mechanical strength of the tested specimens was closely related to the tissue regeneration within the bone defect. Progressive regeneration of new bone was observed at each stage, with complete bone formation at the 9-month period. A consistent increase in both maximal compressive stress and maximal shear stress was noted at each stage, responsive to the ossification and maturation of the regenerating tissue within the bone defect. This animal model provides a novel approach to directly estimate the tissue strength of the HA-implanted bone defect.
本研究的目的是调查植入48只成年杂种犬股骨所造骨缺损内的颗粒状羟基磷灰石（HA）的生物力学行为和组织学情况。骨缺损尺寸为10×10×25毫米，分为植入HA和未植入HA两组，术后分别任其愈合至第1、2、3、6、9和12个月结束。从植入部位采集的组织标本被加工成长方体或长方体棱柱形式。通过压缩和剪切试验评估其机械强度，通过对标本中部施力加载来测量最大压缩应力和剪切应力。每个阶段的组织学切片都采用脱钙和未脱钙两种方法进行处理。结果表明，测试标本的机械强度与骨缺损内的组织再生密切相关。在每个阶段都观察到新骨的渐进性再生，在9个月时形成完全的骨组织。随着骨缺损内再生组织的骨化和成熟，每个阶段的最大压缩应力和最大剪切应力均持续增加。该动物模型提供了一种直接估计植入HA的骨缺损组织强度的新方法。
