EVALUATION OF MERCURY RELEASE FROM DENTAL AMALGAMS

描述（改编自研究者摘要）： 本申请旨在确定 该合金的配方减少了汞（Hg）从牙科汞合金中的释放。一 将准备一系列合金来检验关于这种效应的具体假设 钯（Pd）添加量、银（Ag）和锡（Sn）的比例以及铜（Cu） 内容预研磨合金的组成和所得到的 银汞合金将通过扫描电子显微探针和扫描 透射电子显微镜与微衍射和XEDA相关联 汞释放随微结构的变化。此外，汞合金将 由与纯Hg和铟（In）-Hg合金混合的合金制备，以进一步 了解铟对减少汞释放的影响，并产生最小的 汞释放制剂。调查人员希望能从商业上确定 在固化过程中和磨损后汞蒸发减少的可行汞合金， 减少汞的溶解。这些汞合金的物理性质将是 评价以验证其是否足以用于临床，并进一步 描述组成对性能的影响。动态溶出， 中性盐和酸性溶液，以及热性能，将是 评估汞合金的稳定性与组成的相关性。最后， 老化汞合金的汞释放与汞含量的变化有关。 微观结构主要假设是汞的释放将被最小化 当汞合金的银汞基质相最有效地稳定时， 表面氧化，这是通过最大限度地增加锡的量来实现的 存在于伽玛1矩阵中。有四个目标： 通过添加Pd，Cu含量的变化和Ag含量的改变， 银汞合金中Sn和Hg的浓度影响汞的蒸发; 确定这些变量影响汞溶解的机制 从牙科汞合金;以验证新合金产生的汞合金， 可接受的物理性能;并验证汞合金在 为期两年。

DESCRIPTION (adapted from the Investigator's abstract): The primary goal of this application is to determine the mechanism by which changes in the formulation of the alloy reduce mercury (Hg) release from dental amalgam. A series of alloys will be prepared to test specific hypotheses about the effect of palladium (Pd) additions, silver (Ag) and tin (Sn) ratio, and copper (Cu) content. The composition of the pre-trituration alloys and the resulting amalgams will be evaluated by scanning electron microprobe and scanning transmission electron microscopy with micro-diffraction and XEDA to correlate changes in Hg release with microstructure. In addition, amalgams will be prepared from alloys mixed with pure Hg and indium (In)-Hg alloys to further understand the effect of indium on reducing Hg release, and to produce minimal Hg-releasing formulations. The investigators expect to identify commercially viable amalgams with reduced Hg vaporization during setting and after abrasion, and reduced Hg dissolution. The physical properties of these amalgams will be evaluated to verify that they are adequate for clinical use and to further describe the effect of composition on properties. Dynamic dissolution into both neutral saline and acidic solutions, as well as thermal properties, will be assessed to correlate the stability of the amalgams with composition. Finally, Hg release from aged amalgams will be correlated with changes in their microstructure. The primary hypothesis is that Hg release will be minimized when the Ag-Hg matrix phase of amalgam is most effectively stabilized and its surface oxidized and that this is accomplished by maximizing the amount of Sn present in the gamma one matrix. There are four aims: to identify the mechanism by which additions of Pd, changes in the Cu content, and alterations in the Ag and Sn concentrations in dental amalgam alloy affect the vaporization of Hg; to identify the mechanism by which those variables affect the dissolution of Hg from dental amalgam; to verify that the new alloys produce amalgams with acceptable physical properties; and to verify that the amalgams are stable over a two year period.