Department of Biomaterials, School of Dentistry, University of Athens, Athens, Greece.
Int Endod J. 2010 Feb;43(2):125-34. doi: 10.1111/j.1365-2591.2009.01651.x.
To evaluate the elemental composition, microstructure and hardness of Ni-Ti endodontic instruments and to assess the relevance of shape memory and superelastic properties.
Ten brands of Ni-Ti endodontic instrument were evaluated (EndoSequence, Ergoflex K, FlexMaster, Hero 642, Hyflex X-File, K3 Endo, Liberator, NRT, Profile and ProTaper). After embedding in resin and metallographic preparation the elemental composition, structure and hardness were evaluated employing SEM/energy-dispersive X-ray spectrometer (EDX), X-ray diffraction (XRD) and microhardness measurements. The results of elemental composition and hardness were analysed statistically by one-way anova followed by SNK test (alpha : 0.05). The correlation between Ni content and microhardness was examined by the Pearson test.
The instruments comprised of Ni (52.1-56.2%wt) and Ti (43.8 to 47.9%wt) and were classified in four different Ni content groups: ProTaper, Liberator, ProFile and K3 demonstrated higher Ni content than Hylfex X-File but lower than Hero 642, NRT and Ergoflex. EndoSequence and FlexMaster had the highest Ni content. XRD analysis revealed the presence of the austenitic structure in all instruments. Vickers hardness values ranged from 312 (K3) to 376 VHN (Endosequence). No correlation (r(2) = 0.026) was found between Ni content and hardness among the instruments tested. Microstructural and hardness data confirm that the Ni-Ti instruments were manufactured by cold worked Ni-Ti and do not posses shape memory or superelastic properties.
The endodontic instruments tested were manufactured from cold worked Ni-Ti wires and thus have neither shape memory nor superelastic properties.
评估镍钛根管器械的元素组成、微观结构和硬度，并评估形状记忆和超弹性性能的相关性。
评估了 10 个品牌的镍钛根管器械（EndoSequence、Ergoflex K、FlexMaster、Hero 642、Hyflex X-File、K3 Endo、Liberator、NRT、Profile 和 ProTaper）。在将样品嵌入树脂并进行金相制备后，使用扫描电子显微镜/能谱仪（SEM/EDX）、X 射线衍射（XRD）和显微硬度测量来评估元素组成、结构和硬度。使用单因素方差分析（ANOVA）和 SNK 检验（alpha：0.05）对元素组成和硬度的结果进行统计学分析。通过 Pearson 检验检查 Ni 含量与显微硬度之间的相关性。
器械由 Ni（52.1-56.2wt%）和 Ti（43.8 至 47.9wt%）组成，并分为四个不同的 Ni 含量组：ProTaper、Liberator、ProFile 和 K3 的 Ni 含量高于 Hylfex X-File，但低于 Hero 642、NRT 和 Ergoflex。EndoSequence 和 FlexMaster 的 Ni 含量最高。XRD 分析表明所有器械均存在奥氏体结构。维氏硬度值范围从 312（K3）到 376 VHN（Endosequence）。在所测试的器械中，未发现 Ni 含量与硬度之间存在相关性（r²=0.026）。微观结构和硬度数据证实，所测试的镍钛器械是由冷加工镍钛制成的，因此不具有形状记忆或超弹性性能。
所测试的根管器械由冷加工镍钛丝制成，因此既没有形状记忆也没有超弹性性能。
