Tahmasbi Soodeh, Sheikh Tahereh, Hemmati Yasamin B
Department of Orthodontics, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran.
General Dentist, Private Practice, Tehran, Islamic Republic of Iran.
J Contemp Dent Pract. 2017 Mar 1;18(3):222-227.
To investigate the galvanic corrosion of brackets manufactured by four different companies coupled with stainless steel (SS) or nickel-titanium (NiTi) wires in an artificial saliva solution.
A total of 24 mandibular central incisor Roth brackets of four different manufacturers (American Orthodontics, Dentaurum, Shinye, ORJ) were used in this experimental study. These brackets were immersed in artificial saliva along with SS or NiTi orthodontic wires (0.016'', round) for 28 days. The electric potential difference of each bracket/ wire coupled with a saturated calomel reference electrode was measured via a voltmeter and recorded constantly. Corrosion rate (CR) was calculated, and release of ions was measured with an atomic absorption spectrometer. Stereomicroscope was used to evaluate all samples. Then, samples with corrosion were further assessed by scanning electron microscope and energy-dispersive X-ray spectroscopy. Two-way analysis of variance was used to analyze data.
Among ions evaluated, release of nickel ions from Shinye brackets was significantly higher than that of other brackets. The mean potential difference was significantly lower in specimens containing a couple of Shinye brackets and SS wire compared with other specimens. No significant difference was observed in the mean CR of various groups (p > 0.05). Microscopic evaluation showed corrosion in two samples only: Shinye bracket coupled with SS wire and American Orthodontics bracket coupled with NiTi wire.
Shinye brackets coupled with SS wire showed more susceptibility to galvanic corrosion. There were no significant differences among specimens in terms of the CR or released ions except the release of Ni ions, which was higher in Shinye brackets.
研究四种不同公司生产的托槽与不锈钢（SS）或镍钛（NiTi）弓丝在人工唾液溶液中的电偶腐蚀情况。
本实验研究共使用了来自四个不同制造商（美国正畸公司、登泰克、新叶、ORJ）的24个下颌中切牙Roth托槽。将这些托槽与SS或NiTi正畸弓丝（0.016英寸，圆形）一起浸泡在人工唾液中28天。通过电压表测量每个托槽/弓丝与饱和甘汞参比电极耦合时的电势差，并持续记录。计算腐蚀速率（CR），并用原子吸收光谱仪测量离子释放量。使用体视显微镜评估所有样本。然后，对有腐蚀的样本通过扫描电子显微镜和能量色散X射线光谱进一步评估。采用双向方差分析来分析数据。
在评估的离子中，新叶托槽释放的镍离子明显高于其他托槽。与其他样本相比，含有一对新叶托槽和SS弓丝的样本的平均电势差明显更低。各组的平均CR无显著差异（p>0.05）。显微镜评估仅在两个样本中显示有腐蚀：新叶托槽与SS弓丝组合以及美国正畸托槽与NiTi弓丝组合。
新叶托槽与SS弓丝组合显示出对电偶腐蚀更敏感。除新叶托槽中镍离子释放量较高外，样本在CR或释放离子方面无显著差异。
