Cyclic voltammetry of dental amalgams.
Cyclic voltammetry of dental amalgams.
复制标题
牙科汞合金的循环伏安法。
DOI：
10.1016/s0109-5641(96)80014-5
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Okabe,T
中科院分区：
文献类型：
--
作者：
Horasawa,N;Nakajima,H;Ferracane,JL;Takahashi,S;Okabe,T
ObjectivesThis study used cyclic voltammetry to examine the effect of the composition of dental amalgams on their electrochemical behaviour，including reactions occurring outside of oral conditions.MethodsAmalgams（residual mercury 47.5%）were prepared using two low-copper（3 wt% Cu）powders and five high-copper powders（40-80 wt% Ag，12-30 wt% Cu）with and without zinc（1.5 wt%）.在37°C下，在1.0%NaCl中，以2 mV/s的速度在-1.5 V至+0.8 V vs. Ag/AgCl.ResultsDuring阳极扫描的电位范围内，获得循环伏安图，AgCl和Hg 2Cl 2膜形成的所有汞齐，除了一个只有40重量%的银。在所有高铜汞合金中，在−0.1 V处发现一个显著的Cu（氧化）峰，表明铜在腐蚀过程中释放。锌影响低铜和高铜汞合金的氧化过程。当不含锌时，Sn 2+的氧化峰出现在-0.4 V处。当含锌时，Sn 4+的氧化峰出现在-0.6 V处。在某些汞合金中，存在锡和铜的选择性腐蚀（点蚀）的证据。在银含量最低的汞合金中，没有形成保护膜，这表明其耐腐蚀性差。正如预期的那样，在所有低铜汞合金中，由于锡从γ 2中释放出来，在0 V时立即记录到电流密度的极大增加。重要性循环伏安法可用于快速检查（不到1小时）汞合金的电化学行为，特别是获得有关化合物形成和电化学反应顺序的信息。
ObjectivesThis study used cyclic voltammetry to examine the effect of the composition of dental amalgams on their electrochemical behavior, including reactions occurring outside of oral conditions.MethodsAmalgams (residual mercury 47.5%) were prepared using two low-copper (3 wt% Cu) powders and five high-copper powders (40–80 wt% Ag, 12–30 wt% Cu) with and without zinc (1.5 wt%). Cyclic voltammograms were obtained at 37°C in 1.0% NaCl scanning at 2 mV/s in the potential range from −1.5 V to +0.8 V vs. Ag/AgCl.ResultsDuring the anodic scans, AgCl and Hg2Cl2films were formed on all amalgams except the one with only 40 wt% Ag. In all high-copper amalgams, a prominent Cu (oxidation) peak was found at −0.1 V, indicating the release of copper during corrosion. Zinc affected the oxidation process for both low- and high-copper amalgams. When zinc was absent, a peak for Sn2+oxidation appeared at −0.4 V. When zinc was present, a Sn4+oxidation peak was revealed at −0.6 V. In some amalgams, there was evidence of the selective corrosion (pitting corrosion) of tin and copper. In the lowest silver-content amalgam, no protective films were formed, which is indicative of its poor corrosion resistance. As expected, in all the low-copper amalgams, an extreme increase in current density was recorded immediately at 0 V, due to the release of tin from γ2.SignificanceCyclic voltammetry is useful for the rapid examination (less than an hour) of the electrochemical behavior of amalgams, specifically to obtain information on the formation of compounds and the sequences of electrochemical reactions.