Surface characterization of retrieved NiTi orthodontic archwires
Surface characterization of retrieved NiTi orthodontic archwires
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DOI：
10.1093/ejo/22.3.317
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发表时间：
2000-06-01
影响因子：
2.6
通讯作者：
Bradley, TG
中科院分区：
文献类型：
--
作者：
Eliades, T;Eliades, G;Bradley, TG
评估回收的NiTi正畸弓线的结构和形态状况，并对体内1-6个月后合金表面成分可能发生的变化进行表征。通过检索方案收集不同截面的NiTi丝（GAC, German Orthodontics， ORMCO），并进行多技术表征。光学显微镜显示岛状的无定形沉淀物和积聚的微晶颗粒。对回收样品进行的微MIR-FTIR研究表明存在蛋白质生物膜，其有机成分主要是酰胺、醇和碳酸盐。扫描电镜和x射线显微分析表明，材料表面析出的元素种类为Na、K、Cl、Ca和P，形成NaCl、KCl和Ca-P相。增加的口腔内暴露始终与成熟膜的存在有关，同时观察到合金分层、点蚀和缝隙腐蚀的证据，以及合金晶粒尺寸的显着减小。口内暴露镍钛金属丝会通过表面腐蚀改变合金表面的形貌和结构，形成点蚀或缝隙腐蚀或形成镀层。需要进一步的体内研究来解决所描述的合金耐腐蚀性老化模式的影响，镍浸出的可能性，以及支架-弓丝摩擦变体。
The structure and morphological condition of retrieved NiTi orthodontic archwires was evaluated and any possible alterations in the surface composition of the alloy following 1-6 months in vivo were characterized. NiTi wires (GAC, German Orthodontics, ORMCO) of various cross-sections were collected through a retrieval protocol and were subjected to multi-technique characterization.Optical microscopy revealed islands of amorphous precipitants and accumulated microcrystalline particles. Micro MIR-FTIR investigation of the retrieved samples demonstrated the presence of a proteinaceous biofilm, the organic constituents of which were mainly amide, alcohol, and carbonate. Scanning electron microscope and X-ray microanalysis showed that the elemental species precipitated on the material surface were Na, K, Cl, Ca, and P, forming NaCl, KCl, and Ca-P precipitates. Increased intra-oral exposure was consistently associated with the presence of a mature film, while evidence of alloy delamination, pitting, and crevice corrosion, as well as a notable reduction in the alloy grain size was observed.Intra-oral exposure of NiTi wires alters the topography and structure of the alloy surface through surface attack in the form of pitting or crevice corrosion or formation of integuments. Further in vivo research is required to resolve the implications of the described ageing pattern in the corrosion resistance of the alloy, the potential for nickel leaching, as well as bracket-archwire friction variants.