Mjör I A, Nordahl I
College of Dentistry, University of Florida, Gainesville 32610-0415, USA.
Arch Oral Biol. 1996 May;41(5):401-12. doi: 10.1016/0003-9969(96)00008-8.
Detailed knowledge of dentine structure, and especially that of the dentinal tubules, is essential in order to understand dentine permeability and to interpret data from investigations on dentine adhesive materials. The aim here was to examine the density and branching of dentinal tubules in human teeth by light and scanning electron microscopy. Stained and unstained demineralized sections and undemineralized fractured specimens were studied. Statistically significant differences in the density of tubules were found depending on location. Differences in density of tubules between the peripheral and inner aspects were more marked in the crown than in root. The mean number of dentinal tubules in the middle part of the root was significantly lower than in the middle part of the crown. The density of the tubules in the outer dentine at the cusp location was also significantly different from that subjacent to the occlusal fissure. The number of branches of dentinal tubules was particularly abundant in locations where the density of tubules was low. The branching patterns revealed an intricate and profuse canalicular, anastomosing system, criss-crossing the intertubular dentine. Three types of branches, major, fine and microbranches, were identified on the basis of size, direction and location. Major branches, 0.5-1.0 micron dia., were the typical delta branchings found peripherally. Fine branches, 300-700 nm dia., forked off at 45 degrees and were abundant in areas such as in the root where the density of the tubules was relatively low. Microbranches, 25-200 nm dia., extended at right angles from the tubules in all parts of the dentine. The findings emphasize the need for detailed characterization of dentine substrates for adhesive testing and of samples used in permeability studies.
要理解牙本质的渗透性并解读有关牙本质粘结材料的研究数据，深入了解牙本质结构，尤其是牙本质小管的结构至关重要。本文旨在通过光学显微镜和扫描电子显微镜检查人类牙齿中牙本质小管的密度和分支情况。研究了染色和未染色的脱矿切片以及未脱矿的断裂标本。结果发现，根据位置不同，小管的密度存在统计学上的显著差异。在牙冠处，外周和内部之间小管密度的差异比牙根处更为明显。牙根中部的牙本质小管平均数量显著低于牙冠中部。牙尖部位外层牙本质中小管的密度也与咬合裂隙下方的显著不同。在小管密度较低的部位，牙本质小管的分支数量特别丰富。分支模式显示出一个复杂且丰富的小管相互吻合系统，纵横交错于管周牙本质中。根据大小、方向和位置，确定了三种类型的分支：主要分支、细小分支和微分支。主要分支直径为0.5 - 1.0微米，是外周典型的三角形分支。细小分支直径为300 - 700纳米，以45度角分叉，在牙根等小管密度相对较低的区域较为丰富。微分支直径为25 - 200纳米，在牙本质各部位均从牙本质小管直角延伸。这些发现强调了在粘结测试中对牙本质底物以及渗透性研究中使用的样本进行详细表征的必要性。
