Holland R I
NIOM, Scandinavian Institute of Dental Materials, Haslum, Norway.
Scand J Dent Res. 1991 Feb;99(1):75-85. doi: 10.1111/j.1600-0722.1991.tb01026.x.
The number and in particular the diversity in types and composition of alloys used in dentistry are increasing, thus enhancing the need for predictive corrosion testing. No corrosion test is generally accepted as being both applicable to and relevant for all dental alloys. However, some methods have gained a certain recognition, and among these are the potentiodynamic polarization techniques. The purpose of the present work was to study the application, the reproducibility and the influence of some methodological variables on the results of potentiodynamic polarization corrosion testing. Embedded specimens of 18 different dental alloys, representing all major types, were subjected to anodic polarization scan within the potential range of -700 mV to 1000 mV (SCE). Artificial saliva, with and without organic compounds, and sodium sulfide solution were used as electrolytes. The results were processed on a microcomputer using locally developed software. The curves of current density versus potential showed fair reproducibility, with great differences between some of the alloys, showing a clear relationship to nobility or passivity of the alloy. There were marked differences between the results obtained in artificial saliva and in sodium sulfide solution, while addition of organic components to the artificial saliva only had a minor effect. The potentiodynamic polarization corrosion test supplies detailed information such as anodic charge, and open circuit, rupture, and passivation potential. Furthermore, it indicates the passive range and sensitivity to pitting corrosion. These are all useful when evaluating the corrosion properties of a dental alloy. An analysis of variance of the results in this study showed that possible differences between the alloys were clearly detectable with this method. However, for alloys releasing non-ionic products during corrosion/degradation, the method may be inappropriate. It is thus concluded that the method appears applicable as an in vitro corrosion test for most dental alloys, with the possible exception of amalgams.
牙科领域使用的合金数量，尤其是合金类型和成分的多样性正在增加，因此对预测性腐蚀测试的需求也在增强。一般而言，没有一种腐蚀测试方法被公认为适用于所有牙科合金且与之相关。然而，一些方法已获得了一定认可，其中包括动电位极化技术。本研究的目的是探讨动电位极化腐蚀测试的应用、可重复性以及一些方法学变量对测试结果的影响。选取了代表所有主要类型的18种不同牙科合金的嵌入式试样，在-700 mV至1000 mV（SCE）的电位范围内进行阳极极化扫描。使用含有和不含有有机化合物的人工唾液以及硫化钠溶液作为电解质。结果通过使用本地开发的软件在微型计算机上进行处理。电流密度与电位的曲线显示出良好的可重复性，一些合金之间存在很大差异，这表明与合金的 nobility 或钝化有明显关系。在人工唾液和硫化钠溶液中获得的结果存在显著差异，而向人工唾液中添加有机成分仅产生轻微影响。动电位极化腐蚀测试可提供详细信息，如阳极电荷、开路电位、破裂电位和钝化电位。此外，它还能表明钝化范围和对点蚀的敏感性。在评估牙科合金的腐蚀性能时，这些信息都很有用。本研究结果的方差分析表明，使用该方法可以清晰地检测出合金之间可能存在的差异。然而，对于在腐蚀/降解过程中释放非离子产物的合金，该方法可能并不适用。因此得出结论，除了汞合金外，该方法似乎适用于大多数牙科合金的体外腐蚀测试。
