Research & Development Headquarters, Lion Corporation, Tokyo, Japan.
Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany.
J Bone Miner Metab. 2021 Sep;39(5):757-768. doi: 10.1007/s00774-021-01227-0. Epub 2021 Apr 11.
Alveolar bone, dentin, and cementum provide a striking example of structurally different collagen-based mineralized tissues separated only by periodontal ligament. While alveolar bone is strongly remodeled, this does not hold for dentin and cementum. However, additional dentin can be deposited on the inner surface of the pulp chamber also in older age. By investigating alveolar bone and molar of mice, the aim of our study is to detect changes in the mineral nanostructure with aging.
Buccal-lingual sections of the mandible and first molar from C57BL/6 mice of three different age groups (young 5 weeks, adult 22 weeks and old 23 months) were characterized using synchrotron small and wide-angle X-ray scattering. Local average thickness and length of the apatite particles were mapped with several line scans covering the alveolar bone and the tooth.
In alveolar bone, a spatial gradient was seen to develop with age with the thickest and longest particles in the distal part of the bone. The mineral particles in dentin were found to be become thicker, but then decrease of average length from adult to old animals. The mineral particle characteristics of dentin close to the pulp chamber were not only different to the rest of the tooth, but also when comparing the different age groups and even between individual animals in the same age group.
These results indicated that mineral particle characteristics were found to evolve differently between molar and alveolar bone as a function of age.
牙槽骨、牙本质和牙骨质为结构不同的胶原基矿化组织提供了一个显著的例子，这些组织仅由牙周韧带隔开。虽然牙槽骨被强烈重塑，但牙本质和牙骨质并非如此。然而，在老年时，牙髓腔的内表面也可以沉积额外的牙本质。通过研究小鼠的牙槽骨和磨牙，我们的研究旨在检测随年龄增长而发生的矿物质纳米结构变化。
使用同步加速器小角和广角 X 射线散射对来自三个不同年龄组（年轻 5 周、成年 22 周和老年 23 个月）的 C57BL/6 小鼠的下颌骨和第一磨牙的颊舌切片进行了表征。使用几条覆盖牙槽骨和牙齿的线扫描图来绘制局部平均厚度和磷灰石颗粒的长度。
在牙槽骨中，随着年龄的增长，观察到一个空间梯度的发展，骨远端的颗粒最厚最长。牙本质中的矿物质颗粒变得更厚，但从成年到老年动物的平均长度却有所下降。靠近牙髓腔的牙本质的矿物质颗粒特征不仅与牙齿的其余部分不同，而且在比较不同年龄组时甚至在同一年龄组的不同个体之间也是如此。
这些结果表明，矿物质颗粒特征随年龄的变化在磨牙和牙槽骨之间表现出不同的演变。
