正畸钛托槽的金相组织与硬度

Zinelis Spiros, Annousaki Olga, Eliades Theodore, Makou Margarita

Biomaterials Laboratory, Section of Basic Sciences and Oral Biology, School of Dentistry, University of Athens, Athens, Greece.

J Orofac Orthop. 2003 Nov;64(6):426-33. doi: 10.1007/s00056-003-0308-5.

AIM

To determine the elemental composition, microstructure, and hardness of two different brands of titanium (Ti) orthodontic brackets.

MATERIALS AND METHODS

Four specimens of each brand were embedded in epoxy resin and, after metallographic grinding and polishing, were studied under a metallographic microscope. The bonding base morphology of each bracket was studied in as-received brackets by scanning electron microscopy. Energy dispersive x-ray microanalysis (EDS) was used on polished specimens to assess the elemental composition of base and wing bracket components, and the brackets were subjected to metallographic etching to reveal the metallurgical structure. The same specimen surfaces were used for assessment of the Vickers hardness. The results were statistically analyzed by two-way analysis of variance (ANOVA) with the bracket brand and bracket region (base, wing) serving as discriminating variables, whilst further group differences were investigated with Tukey's multiple comparison test at the alpha = 0.05 level of significance.

RESULTS

Metallographic imaging revealed that the Orthos2 brackets (Ormco, Glendora, CA, USA) consist of two parts joined together by laser welding, with large gaps along the base wing interface, whereas Rematitan brackets (Dentaurum, Ispringen, Germany) are single-piece appliances. Ti was the only element identified in Rematitan and Orthos2 base materials, while aluminium (Al) and vanadium (V) were also found in the Orthos2 wing component. Metallographic analysis showed the presence of a + b phase for Orthos2 and plate-like grains for Rematitan. The results of the Vickers hardness testing were: Orthos2 (wing): 371 +/- 22, Rematitan (wing): 272 +/- 4, Rematitan (base): 271 +/- 16, Orthos2 (base): 165 +/- 2.

CONCLUSION

The findings of the present study suggest that there are significant differences in composition, microstructure and hardness between the two commercial types of Ti brackets tested; the clinical implications of the findings are discussed.

目的

确定两种不同品牌的钛（Ti）正畸托槽的元素组成、微观结构和硬度。

材料与方法

将每个品牌的四个样本嵌入环氧树脂中，经过金相研磨和抛光后，在金相显微镜下进行研究。通过扫描电子显微镜研究每个托槽在接收状态下的粘结基底形态。对抛光后的样本使用能量色散X射线微分析（EDS）来评估基底和翼托槽组件的元素组成，并对托槽进行金相蚀刻以揭示金相结构。使用相同的样本表面评估维氏硬度。结果通过双向方差分析（ANOVA）进行统计分析，将托槽品牌和托槽区域（基底、翼）作为区分变量，同时在α = 0.05的显著性水平下，使用Tukey多重比较检验进一步研究组间差异。

结果

金相成像显示，Ortho2托槽（美国加利福尼亚州格伦多拉市奥美科公司）由通过激光焊接连接在一起的两部分组成，沿基底 - 翼界面存在较大间隙，而Rematitan托槽（德国伊斯普林根市登泰克公司）是一体式器具。在Rematitan和Ortho2基底材料中仅鉴定出Ti元素，而在Ortho2翼组件中还发现了铝（Al）和钒（V）。金相分析表明，Ortho2存在α + β相，Rematitan存在板状晶粒。维氏硬度测试结果为：Ortho2（翼）：371±22，Rematitan（翼）：272±4，Rematitan（基底）：271±16，Ortho2（基底）：165±2。