The Distribution of Carbonate in Enamel and its Correlation with Structure and Mechanical Properties.
The Distribution of Carbonate in Enamel and its Correlation with Structure and Mechanical Properties.
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DOI：
10.1007/s10853-012-6693-7
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发表时间：
2012-12
影响因子：
4.5
通讯作者：
Walker, Mary P.
中科院分区：
文献类型：
--
作者：
Xu, Changqi;Reed, Rachel;Gorski, Jeffrey P.;Wang, Yong;Walker, Mary P.
通过拉曼显微光谱和纳米压痕的线性映射分析，评估了碳酸盐含量与牙釉质微观结构（化学和晶体结构）和力学性能的相关性。映射开始于外牙釉质表面，结束于靠近牙本质-牙釉质交界处（DEJ）的内牙釉质，在舌区和颊区，颈区和尖区。1070 cm−1处碳酸盐峰强度由外向内逐渐增大。此外，以960 cm−1峰的半峰全宽（FWHM）测量的磷酸盐峰宽也有所增加，从外层釉质的~9 cm−1增加到靠近DEJ的釉质的~13 cm−1，表明羟基磷灰石从外层到内部釉质的结晶度有所下降。相比之下，牙釉质的杨氏模量从119±12 GPa下降到80±19 GPa，牙釉质硬度从5.9±1.4 GPa下降到3.5±1.3 GPa。碳酸盐含量和相关结晶度与力学性能之间也存在显著的相关性。随着碳酸盐含量的增加，结晶度随之降低，这两种变化都与模量和硬度的降低有关。综上所述，这些结果表明，牙釉质碳酸盐含量及其相关的羟基磷灰石晶体结构的变化，即结晶度，可能直接影响牙釉质的力学性能。拉曼显微光谱与纳米压痕的结合是评价牙釉质微观结构及其相关性能的有效方法。
The correlation of carbonate content with enamel microstructure (chemical and crystal structure) and mechanical properties was evaluated via linear mapping analyses using Raman microspectroscopy and nanoindentation. Mappings started at the outer enamel surface and ended in the inner enamel near the dentin-enamel junction (DEJ) in lingual and buccal cervical and cuspal regions. The carbonate peak intensity at 1070 cm−1 gradually increased from outer to inner enamel. Moreover, the phosphate peak width, as measured by the full width at half maximum (FWHM) of the peak at 960 cm−1, also increased, going from ~9 cm−1 in outer enamel to ~13 cm−1 in enamel adjacent to the DEJ, indicating a decrease in the degree of crystallinity of hydroxyapatite from outer to inner enamel. In contrast, Young’s modulus decreased from 119±12 to 80±19 GPa across outer to inner enamel with a concomitant decrease in enamel hardness from 5.9±1.4 to 3.5±1.3 GPa. There were also significant correlations between carbonate content and associated crystallinity with mechanical properties. As carbonate content increased, there was an associated decrease in crystallinity and both of these changes correlated with decreased modulus and hardness. Collectively, these results suggest that enamel carbonate content and the associated change in the crystal structure of hydroxyapatite, i.e. degree of crystallinity, may have a direct effect on enamel mechanical properties. The combination of Raman microspectroscopy and nanoindentation proved to be an effective approach for evaluating the microstructure of enamel and its associated properties.
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影响因子：
6.1
作者：
Pappas, D;Smith, BW;Winefordner, JD
通讯作者：
Winefordner, JD
影响因子：
2.6
作者：
Sternlieb, Mitchell P.;Pasteris, Jill D.;Yoder, Claude H.
通讯作者：
Yoder, Claude H.
影响因子：
3
作者：
Cuy, JL;Mann, AB;Weihs, TP
通讯作者：
Weihs, TP
影响因子：
8.6
作者：
PARAYANTHAL, P;POLLAK, FH
通讯作者：
POLLAK, FH
影响因子：
2.8
作者：
Darnell, Laura A.;Teaford, Mark F.;Weihs, Timothy P.
通讯作者：
Weihs, Timothy P.