EVALUATION OF MERCURY RELEASE FROM DENTAL AMALGAMS

说明(改编自调查员摘要)：的主要目标 此应用程序用于确定 该合金配方可减少牙科汞齐中汞(Hg)的释放。一个 将准备一系列合金来测试关于这一效应的具体假设 添加钯(Pd)、银(银)和锡(锡)的比率，以及铜(铜) 内容。预磨合金的成分和由此产生的 银汞合金将通过扫描电子探针和扫描进行评估 透射电子显微镜显微衍射与XEDA的关联 汞释放随微结构的变化。此外，汞齐将是 由合金与纯汞和铟(In)-汞合金混合制备，以进一步 了解铟对减少汞释放的影响，并产生最低限度的汞 汞释放制剂。调查人员希望在商业上确定 在固化和磨损后汞蒸发量减少的可行汞齐， 减少汞的溶解。这些汞齐的物理性质将是 评估以验证它们是否适合临床使用，并进一步 描述成分对性能的影响。动态地分解为两者 中性盐溶液和酸性溶液，以及热性能 评估将汞齐的稳定性与组成相关联。最后， 老化银汞合金中汞的释放将与其 微观结构。主要的假设是汞的排放量将降至最低 当银汞合金的银汞基质相最有效地稳定时，其 表面氧化，这是通过最大限度地增加锡的量来实现的 出现在伽马一号矩阵中。有四个目标：确定机制 Pd的添加，铜含量的变化，以及银的变化 牙科银汞合金中锡的浓度影响汞的汽化； 确定这些变量影响汞溶解的机制 从牙科银汞合金；以验证新的合金产生的汞合金与 可接受的物理性能；并验证汞齐在 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.