Varma D Praveen Kumar, Chidambaram S, Reddy K Baburam, Vijay M, Ravindranath D, Prasad M Rajendra
Professor, Department of Orthodontics, Vishnu Dental College Bhimavaram-534202, Andhra Pradesh, India, e-mail:
J Contemp Dent Pract. 2013 May 1;14(3):488-95. doi: 10.5005/jp-journals-10024-1350.
The aim of the study is to investigate the galvanic corrosion potential of metal injection molding (MIM) brackets to that of conventional brackets under similar in vitro conditions with nickel-titanium and copper nickel-titanium archwires.
Twenty-five maxillary premolar MIM stainless steel brackets and 25 conventional stainless steel brackets and archwires, 0.16 inch, each 10 mm length, 25 nickeltitanium wires, 25 copper nickel-titanium wires were used. They were divided into four groups which had five samples each. Combination of MIM bracket with copper nickel-titanium wire, MIM bracket with nickel-titanium wire and conventional stainless steel brackets with copper nickel-titanium wire and conventional stainless steel brackets with nickel-titanium wires which later were suspended in 350 ml of 1 M lactic acid solution media. Galvanic corrosion potential of four groups were analyzed under similar in vitro conditions. Precorrosion and postcorrosion elemental composition of MIM and conventional stainless steel bracket by scanning electron microscope (SEM) with energy dispersive spectroscope (EDS) was done.
MIM bracket showed decreased corrosion susceptibility than conventional bracket with copper nickeltitanium wire. Both MIM and conventional bracket showed similar corrosion resistance potential in association with nickel-titanium archwires. It seems that both brackets are more compatible with copper nickel-titanium archwires regarding the decrease in the consequences of galvanic reaction. The EDS analysis showed that the MIM brackets with copper nickel-titanium wires released less metal ions than conventional bracket with copper nickeltitanium wires.
MIM brackets showed decreased corrosion susceptibility, copper nickel-titanium archwires are compatible with both the brackets than nickel-titanium archwires.
Clinically MIM and conventional brackets behaved more or less similarly in terms of corrosion resistance. In order to decrease the corrosion potential of MIM brackets, more precise manufacturing technique should be improved to get a more smoother surface finish.
本研究旨在探讨在类似的体外条件下，金属注射成型（MIM）托槽与传统托槽在使用镍钛和铜镍钛弓丝时的电偶腐蚀电位。
使用25个上颌前磨牙MIM不锈钢托槽、25个传统不锈钢托槽以及弓丝，弓丝为0.16英寸，每段长度为10毫米，25根镍钛丝，25根铜镍钛丝。它们被分为四组，每组有五个样本。MIM托槽与铜镍钛丝的组合、MIM托槽与镍钛丝的组合、传统不锈钢托槽与铜镍钛丝的组合以及传统不锈钢托槽与镍钛丝的组合，随后将其悬浮在350毫升1M乳酸溶液介质中。在类似的体外条件下分析四组的电偶腐蚀电位。通过扫描电子显微镜（SEM）和能谱仪（EDS）对MIM和传统不锈钢托槽的腐蚀前和腐蚀后元素组成进行分析。
MIM托槽与铜镍钛丝相比，显示出比传统托槽更低的腐蚀敏感性。MIM托槽和传统托槽在与镍钛弓丝结合时显示出相似的耐腐蚀电位。就电偶反应后果的降低而言似乎两种托槽与铜镍钛弓丝都更兼容。EDS分析表明，MIM托槽与铜镍钛丝相比释放的金属离子比传统托槽与铜镍钛丝释放的少。
MIM托槽显示出较低的腐蚀敏感性，铜镍钛弓丝与两种托槽都比镍钛弓丝更兼容。
临床上MIM托槽和传统托槽在耐腐蚀性方面表现或多或少相似。为了降低MIM托槽的腐蚀电位，应改进更精确制造技术以获得更光滑的表面光洁度。
