口腔修复常用合金间瞬间电偶电流值的测定

Measuration of Instantly Galvanic Current Magnitude among Dental Common Restorative Alloys

目的测定异种金属咬合接触时产生的电流值。方法在人工唾液中体外模拟异种金属(金合金、纯钛、高含锌银汞和低含锌银汞)瞬间咬合接触时的回路。记录浸泡初各偶对的电位及瞬间接触电流值,继续浸泡8h后再次测量,记录瞬间接触电流值。结果多次瞬间接触引起的电流值变化无规律性。初浸时,金合金/纯钛、金合金/高含锌银汞、低含锌银汞/高含锌银汞偶对产生较大的峰值电流,纯钛/高含锌银汞偶对与其他偶对的电流值间差别有统计学意义(P<0.05);浸泡8h后,纯钛/高含锌银汞、纯钛/低含锌银汞偶对分别与金合金/纯钛、金合金/低含锌银汞、金合金/高含锌银汞的电流值间差别有统计学意义(P<0.05);偶对浸泡8h前后相比,只有金合金/高含锌银汞偶对的电流值间差别没有统计学意义(P>0.05),金合金/低含锌银汞、纯钛/高含锌银汞的电流增加。高含锌银汞的电位较负,而且实验中始终为阳极,被加速腐蚀。结论临床医师不可忽视使用异种金属修复体早期无不适感的病例。金合金/纯钛、金合金/高含锌银汞、低含锌银汞/高含锌银汞偶对若存在于口腔中,有可能对患者造成危害。金合金/低含锌银汞、纯钛/高含锌银汞偶对也不宜共存于口腔中。临床应尽量使用低含锌银汞或者无锌银汞合金。

Objective To measure the magnitude of galvanic currents produced by different occluding metallic contact. Methods The circuits of instantly different metallic contact were simulated in artificial saliva, and electrical potential of every couple and 15 currents of instant contact were then measured. After 8 hours＇ soaking, 15 currents were obtained in addition. Results Galvanic currents variation produced by intermittently metallic contact was ruleless. During early soaking, gold/titanium, gold/high zinc-containing amalgam and low/high zinc-containing amalgam exhibited much higher current, and there was significant difference on currents between titanium/high zinc-containing amalgam and other couples （P〈0.05）. There was also significant difference on currents between titanium/high zinc- containing amalgam, titanium/low zinc-containing amalgam and gold/titanium, gold/low zinc-containing amalgam and gold/high zinc-containing amalgam after 8 hours＇ soaking （P〈0.05）. In contrast with currents produced by couples before and after 8 hours＇ soaking, only the currents produced by gold/high zinc-containing amalgam proved to be no significant of difference （P〉0.05）, while the currents produced by gold/low zinc-containing amalgam and thanium/high zinc-containing amalgam increased. Potential of high zinc-containing amalgam was more negative than other alloys, and it was always under anodic behavior during the experiment corrupted acceleratedly. Conclusion Dentists can＇t ignore the case that the patient feels normal at the beginning of wearing different occluding metallic restorations. Either of gold/ titatium, gold/high zinc-containing amalgam and low/high zinc-containing amalgam appearing in oral will do harm to the patients＇ health. Neither of gold/low zinc-containing amalgam nor titanium/high zinc-containing amalgam can coexist in oral. Zinc-free or low zinc-containing amalgam should be selected instead of high zinc-containing amalgam.