Dipartimento di Scienze Odontostomatologiche, Università degli Studi Sapienza, Rome, Italy.
Ann Ist Super Sanita. 2009;45(4):423-6. doi: 10.1590/s0021-25712009000400011.
A new manufacturing method of twisting nickel titanium wire to produce rotary nickel titanium (RNT) files has recently been developed. The aim of the present study was to evaluate whether the new manufacturing process increased the angular deflection of RNT files, by comparing instruments produced using the new manufacturing method (Twisted Files) versus instruments produced with the traditional grinding process. Testing was performed on a total of 40 instruments of the following commercially available RNT files: Twisted Files (TF), Profile, K3 and M2 (NRT). All instruments tested had the same dimensions (taper 0.06 and tip size 25). Test procedures strictly followed ISO 3630-1. Data were collected and statistically analyzed by means ANOVA test. The results showed that TF demonstrated significantly higher average angular deflection levels (P<0.05), than RNT manufactured by a grinding process. Since angular deflection represent the amount of rotation (and consequently deformation) that a RNT file can withstand before torsional failure, such a significant improvement is a favorable property for the clinical use of the tested RNT files.
一种新的扭镍钛丝制造方法（TWISTED FILES）最近被开发出来，用于生产旋转镍钛（RNT）锉。本研究旨在评估新的制造工艺是否会增加 RNT 锉的角度偏移，方法是比较使用新制造方法（TWISTED FILES）生产的器械与使用传统磨削工艺生产的器械。共测试了以下四种市售 RNT 锉的 40 个器械：TWISTED FILES（TF）、Profile、K3 和 M2（NRT）。所有测试器械的尺寸相同（锥度 0.06，尖端尺寸 25）。测试程序严格遵循 ISO 3630-1。使用 ANOVA 检验对数据进行收集和统计分析。结果表明，TF 表现出显著更高的平均角度偏移水平（P<0.05），高于通过磨削工艺制造的 RNT。由于角度偏移表示 RNT 锉在扭转变形失效之前能够承受的旋转量（因此也是变形量），因此这种显著的改进是测试的 RNT 锉临床应用的有利特性。
