Uniaxial compressive behavior of micro-pillars of dental enamel characterized in multiple directions.
Uniaxial compressive behavior of micro-pillars of dental enamel characterized in multiple directions.
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DOI：
10.1016/j.actbio.2015.01.015
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发表时间：
2015-04
影响因子：
9.7
通讯作者：
Ezgi D. Yilmaz;H. Jelitto;G. Schneider
中科院分区：
文献类型：
--
作者：
Ezgi D. Yilmaz;H. Jelitto;G. Schneider
本文采用单轴微压缩法测定了羟基磷灰石(HA)纳米纤维与有机质形成的牛牙釉质在纵向、横向和斜向的压缩弹性模量值和破坏强度。这里测量的弹性模量值(∼70 GPA)在文献报道的范围内，但这些值在所有方向上都惊人地一致，与先前揭示牙釉质各向异性弹性性质的纳米压痕结果相反。破坏强度记录高达∼1.7GPA，并可视化了不同的破坏模式(如剪切、微屈曲、纤维断裂)与HA纳米纤维的取向有关。结构不规则性导致纳米纤维之间的矿物接触被认为是导致牙釉质第一层次上高压缩强度和方向无关弹性行为的主要原因。
In this work, the compressive elastic modulus and failure strength values of bovine enamel at the first hierarchical level formed by hydroxyapatite (HA) nanofibers and organic matter are identified in longitudinal, transverse and oblique direction with the uniaxial micro-compression method. The elastic modulus values (∼70 GPa) measured here are within the range of results reported in the literature but these values were found surprisingly uniform in all orientations as opposed to the previous nanoindentation findings revealing anisotropic elastic properties in enamel. Failure strengths were recorded up to ∼1.7 GPa and different failure modes (such as shear, microbuckling, fiber fracture) governed by the orientation of the HA nanofibers were visualized. Structural irregularities leading to mineral contacts between the nanofibers are postulated as the main reason for the high compressive strength and direction-independent elastic behavior on enamels first hierarchical level.