Migration of mercury from dental amalgam through human teeth
Migration of mercury from dental amalgam through human teeth
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DOI：
10.1107/s0909049507061468
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发表时间：
2008-03-01
影响因子：
2.5
通讯作者：
Lay, Peter A.
中科院分区：
文献类型：
--
作者：
Harris, Hugh H.;Vogt, Stefan;Lay, Peter A.
一般认为，牙科汞合金中的汞暴露可能会对健康产生负面影响，其发生途径是直接从填充物表面侵蚀或蒸发，然后摄入。本研究的目的是确定汞通过牙齿直接迁移作为替代暴露途径的相对重要性。用X射线荧光成像技术定量测定了汞合金充填20年以上的人牙切片中Hg、Ca、Zn、Cu的空间分布。X射线吸收近边光谱（XANES）也被用来获得牙齿中汞的化学信息。在离汞合金位置几毫米的牙齿中检测到汞（接近10毫克克（-1））和锌（>100毫克克（-1））。在高分辨率下，Hg在牙本质小管中显示出较高的浓度，而Zn通常均匀分布。XANES分析表明，迁移到牙齿中的汞的化学形式与汞合金中的汞的化学形式不同。汞和锌的不同空间分布表明这两种金属不同的运输机制，可能是化学的锌和最初的物理汞。随后汞的氧化可能导致流动性的丧失或形成次级运输机制。最重要的是，在曾经含有活跃血流的牙齿区域和牙石中检测到汞，表明这两种接触途径都应被视为重要途径。(C)2008年国际晶体学联合会。
Exposure to mercury from dental amalgams, with possible negative health effects, has generally been considered to occur via either erosion or evaporation directly from the surface of fillings, followed by ingestion. The aim of this study was to determine the relative importance of the direct migration of mercury through the tooth as an alternative exposure pathway. X-ray fluorescence imaging has been used to determine quantitatively the spatial distribution of Hg, Ca, Zn and Cu in sections of human teeth that had been filled with amalgam for more than 20 years. X-ray absorption near-edge spectroscopy (XANES) was also employed to gain chemical information on the mercury present in the teeth. Hg (up to similar to 10 mg g(-1)) and Zn (>100 mg g(-1)) were detected in the teeth several millimetres from the location of the amalgams. At high resolution, Hg showed higher concentrations in dentinal tubules while Zn was generally evenly distributed. XANES showed that the chemical form of Hg that had migrated into the tooth had been altered from that present in the amalgam. The differing spatial distributions of Hg and Zn suggest distinct transport mechanisms for the two metals, presumably chemical for Zn and initially physical for Hg. Subsequent oxidation of Hg may lead to a loss of mobility or the development of a secondary transport mechanism. Most importantly the detection of Hg in areas of the tooth that once contained an active bloodstream and in calculus indicates that both exposure pathways should be considered as significant. (C) 2008 International Union of Crystallography.