Department of Orthodontics, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands,
J Bone Miner Metab. 2014 Jan;32(1):29-37. doi: 10.1007/s00774-013-0464-7. Epub 2013 Apr 28.
The aim of this study was to correlate the local tissue mineral density (TMD) with the bone tissue stiffness. It was hypothesized that these variables are positively correlated. Cancellous and cortical bone samples were derived from ten mandibular condyles taken from 5 young and 5 adult female pigs. The bone tissue stiffness was assessed in three directions using nanoindentation. At each of three tested sides 5 indents were made over the width of 5 single bone elements, resulting in a total number of 1500 indents. MicroCT was used to determine the local TMD at the indented sites. The TMD and the bone tissue stiffness were higher in bone from the adult animals than from the young ones, but did not differ between cancellous and cortical bone. In the adult group, both the TMD and the bone tissue stiffness were higher in the center than at the surface of the bone elements. The mean TMD, thus ignoring the local mineral distribution, had a coefficient of determination (R(2)) with the mean bone tissue stiffness of 0.55, p < 0.05, whereas the correlation between local bone tissue stiffness and the concomitant TMD appeared to be weak (R (2) 0.07, p < 0.001). It was concluded that the mineralization degree plays a larger role in bone tissue stiffness in cancellous than in cortical bone. Our data based on bone from the mandibular condyle suggest that the mineralization degree is not a decisive determinant of the local bone tissue stiffness.
本研究旨在探讨组织局部骨密度（TMD）与骨组织硬度之间的相关性，并假设两者呈正相关。研究从 5 只年轻雌性猪和 5 只成年雌性猪的下颌骨髁突中获取松质骨和皮质骨样本。采用纳米压痕法在三个方向上评估骨组织硬度。在三个测试侧的每一侧，在 5 个单个骨元素的宽度上进行 5 次压痕，总共进行了 1500 次压痕。微 CT 用于确定压痕部位的局部 TMD。结果显示，成年动物的骨组织 TMD 和骨组织硬度均高于年轻动物，但松质骨和皮质骨之间无差异。在成年组中，骨元素中心的 TMD 和骨组织硬度均高于表面。忽略局部矿物质分布的平均 TMD 与平均骨组织硬度之间的决定系数（R²）为 0.55，p<0.05，而局部骨组织硬度与同时的 TMD 之间的相关性似乎较弱（R²为 0.07，p<0.001）。研究得出结论，矿物质化程度在松质骨中对骨组织硬度的影响大于皮质骨。本研究基于下颌骨髁突的骨组织数据表明，矿物质化程度不是局部骨组织硬度的决定性因素。
