Dentsply Tulsa Dental Specialties, Tulsa, Oklahoma, USA.
J Endod. 2012 Mar;38(3):398-401. doi: 10.1016/j.joen.2011.11.004. Epub 2011 Dec 15.
In this in vitro study, raw materials (including stainless steel, conventional superelastic nickel-titanium [NiTi], M-Wire NiTi, and Vortex Blue NiTi) were used to create ProFile Vortex designed 25/.06 instruments and subject these instruments to testing for fatigue resistance, torsional properties, flexibility, and Vickers microhardness. The comparative results in this study will enable the clinician's understanding of the performance of these materials for better choices in application during endodontic procedures.
Cyclic fatigue testing was performed by rotating files in an artificially constructed stainless steel canal with a 5-mm radius and a 90° angle of curvature at 500 rpm. Torsional properties and flexibility in bending were assessed according to specification ISO 3630-1. Vickers microhardness was measured on the cross section of instruments with 300-g load and 15-second dwell time.
There were significant differences in the average fatigue life and flexibility for instruments made of different materials (P < .05). Vortex Blue was ranked first in both fatigue and flexibility, followed by M-Wire, superelastic wire, and stainless steel. For torsional strength and microhardness, stainless steel and M-Wire were ranked first and second, respectively. There was no statistically significant difference between superelastic wire and Vortex Blue. Vortex Blue showed the greatest distortion angle at break, whereas the other 3 materials showed comparable degree of rotation in the torque test.
Under the limitations of this study, NiTi shape memory alloy appeared to be a superior material option compared with stainless steel for its use in the application of endodontic rotary instruments. Vortex Blue and M-Wire offered functional advantages over conventional superelastic NiTi. Vortex Blue showed improved fatigue resistance and flexibility compared with ProFile Vortex M-Wire.
本体外研究使用原材料（包括不锈钢、传统超弹性镍钛（NiTi）、M-Wire NiTi 和 Vortex Blue NiTi）制作 ProFile Vortex 设计的 25/.06 器械，并对这些器械进行疲劳阻力、扭力性能、柔韧性和维氏显微硬度测试。本研究的对比结果将使临床医生了解这些材料的性能，以便在根管治疗过程中更好地选择应用。
通过在半径为 5mm、曲率为 90°的人工不锈钢管中以 500rpm 的速度旋转锉来进行循环疲劳测试。根据 ISO 3630-1 规范评估扭转性能和弯曲柔韧性。在 300g 载荷和 15 秒停留时间下测量器械横截面的维氏显微硬度。
不同材料制成的器械的平均疲劳寿命和柔韧性存在显著差异（P<.05）。Vortex Blue 在疲劳和柔韧性方面均排名第一，其次是 M-Wire、超弹性丝和不锈钢。在扭力强度和显微硬度方面，不锈钢和 M-Wire 分别排名第一和第二，超弹性丝和 Vortex Blue 之间无统计学差异。Vortex Blue 在断裂时显示出最大的变形角度，而其他 3 种材料在扭矩测试中显示出相似的旋转程度。
在本研究的限制条件下，镍钛形状记忆合金似乎比不锈钢更适合用于根管旋转器械的应用，因为它具有更好的性能。Vortex Blue 和 M-Wire 比传统超弹性 NiTi 具有功能优势。Vortex Blue 与 ProFile Vortex M-Wire 相比，显示出更好的抗疲劳性和柔韧性。
