Role of prism decussation on fatigue crack growth and fracture of human enamel.
Role of prism decussation on fatigue crack growth and fracture of human enamel.
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DOI：
10.1016/j.actbio.2009.04.013
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发表时间：
2009-10
影响因子：
9.7
通讯作者：
Arola, Dwayne
中科院分区：
文献类型：
--
作者：
Bajaj, Devendra;Arola, Dwayne
评价了棱柱讨论对人牙釉质抗裂纹生长的作用。微型嵌套紧致张力（CT）标本包含牙尖牙釉质的一个部分受到模式I循环或单调载荷。裂缝沿正向（从外牙釉质向内）或反向（从内牙釉质向外）方向生长，并定量比较响应。结果表明，外牙釉质对裂纹的产生和生长具有较低的抵抗能力。无论扩展方向如何，循环扩展的近阈值区域都表现为典型的“短裂纹”行为（即随着裂纹长度的增加而减速）。正向循环裂纹扩展更为稳定，其发生的空间距离是反向循环裂纹扩展空间距离的两倍以上。在单调荷载作用下，r曲线响应呈上升趋势，仅表现为正向增长。裂缝正向吸收的总能量是反向吸收的3倍以上。裂纹生长阻力的上升主要是由于裂纹桥接、裂纹分岔和裂纹弯曲等机制的共同作用，这些机制是由内牙釉质的讨论引起的。对反应的分析表明，牙釉质的微观结构似乎优化了，可以抵抗牙齿表面损伤引起的裂纹增长。
The role of prism decussation on the crack growth resistance of human enamel is evaluated. Miniature inset Compact Tension (CT) specimens embodying a section of cuspal enamel were subjected to Mode I cyclic or monotonic loads. Cracks were grown in either the forward (from outer enamel inwards) or reverse (from inner enamel outwards) direction and the responses were compared quantitatively. Results showed that the outer enamel exhibits lower resistance to the inception and growth of cracks. Regardless of the growth direction, the near threshold region of cyclic extension was typical of ‘short crack’ behavior (i.e. deceleration of growth with an increase in crack length). Cyclic crack growth was more stable in the forward direction and occurred over twice the spatial distance achieved in the reverse direction. In response to the monotonic loads, a rising R-curve response was exhibited by growth in the forward direction only. The total energy absorbed in fracture for the forward direction was more than three times that in the reverse. The rise in crack growth resistance was largely attributed to a combination of mechanisms that included crack bridging, crack bifurcation and crack curving, which were induced by decussation in the inner enamel. An analysis of the responses distinguished that the microstructure of enamel appears optimized for resisting crack growth initiating from damage at the tooth’s surface.
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比较人搪瓷和羟基磷灰石疲劳裂纹的生长。
影响因子：
14
作者：
Bajaj, Devendra;Nazari, Ahmad;Eidelman, Naomi;Arola, Dwayne D.
通讯作者：
Arola, Dwayne D.
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作者：
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通讯作者：
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影响因子：
14
作者：
Bajaj, Devendra;Arola, Dwayne D.
通讯作者：
Arola, Dwayne D.
影响因子：
14
作者：
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通讯作者：
Ritchie, RO