Department of General Surgery and Surgical - Medical Specialties, University of Catania, Catania, Italy.
Department of Endodontics and Restorative Dentistry, University of Siena, Siena, Italy.
Int Endod J. 2018 May;51(5):522-528. doi: 10.1111/iej.12769. Epub 2017 Apr 25.
To evaluate the resistance to cyclic fatigue of ProTaper Next (PTN; Dentsply Sirona, Ballaigues, Switzerland), Revo-S (Micro-Mega, Besançon, France), Mtwo (Sweden & Martina, Padova, Italy), Twisted Files (TF, SybronEndo, Orange, CA, USA) and EndoWave (J Morita Corporation, Osaka, Japan) used in continuous rotation or in reciprocation of Optimum Torque Reverse motion (OTR).
A total of 120 nickel-titanium files were tested. Twenty-four instruments for each brand were divided into two groups (n = 12) on the basis of the motion tested: continuous rotation (Group 1) or reciprocation of OTR motion (Group 2). Resistance to cyclic fatigue was determined by recording time to fracture (TtF) in a stainless steel artificial canal with a 60° angle of curvature and 5 mm radius of curvature. The TtF data were analysed by using two-way analysis of variance (anova) and Bonferroni's post hoc tests at 0.05.
Mtwo and TF had significantly higher TtF when compared with all other instruments, both in continuous rotation and in reciprocation of OTR motion (P < 0.0001 and P < 0.05, respectively). No difference was observed between Mtwo and TF (P > 0.05), in both motions. PTN was associated with higher cyclic fatigue resistance than Revo-S and EndoWave, both in continuous rotation and in reciprocation of OTR motions (P < 0.0001). No difference was observed between Revo-S and EndoWave, in both motions (P > 0.05). Reciprocating OTR motion improved TtF of all instruments (P < 0.0001).
Reciprocation of OTR motion improved significantly cyclic fatigue resistance of all instruments tested compared with continuous rotation. Mtwo and TF had significantly higher cyclic fatigue than the other instruments, in both continuous rotation and reciprocation of OTR motion.
评估 ProTaper Next（PTN；登士柏西诺德，Ballaigues，瑞士）、Revo-S（Micro-Mega，Besançon，法国）、Mtwo（瑞典和 Martina，帕多瓦，意大利）、Twisted Files（TF，登士柏 SybronEndo，橙，CA，美国）和 EndoWave（J Morita 公司，大阪，日本）在连续旋转或 Optimum Torque Reverse 运动（OTR）的往复运动中对循环疲劳的抵抗能力。
共测试了 120 根镍钛锉。每个品牌的 24 个器械根据所测试的运动分为两组（n=12）：连续旋转（第 1 组）或 OTR 运动的往复运动（第 2 组）。通过在不锈钢人工弯曲根管（60°弯曲角和 5mm 曲率半径）中记录断裂时间（TtF）来确定抗循环疲劳能力。使用双向方差分析（anova）和 Bonferroni 事后检验对 TtF 数据进行分析，检验水平为 0.05。
与所有其他器械相比，Mtwo 和 TF 在连续旋转和 OTR 运动的往复运动中均具有显著更高的 TtF（P<0.0001 和 P<0.05）。在两种运动中，Mtwo 和 TF 之间没有差异（P>0.05）。在连续旋转和 OTR 运动的往复运动中，PTN 的循环疲劳阻力均高于 Revo-S 和 EndoWave（P<0.0001）。在两种运动中，Revo-S 和 EndoWave 之间没有差异（P>0.05）。OTR 运动的往复运动提高了所有器械的 TtF（P<0.0001）。
与连续旋转相比，OTR 运动的往复运动显著提高了所有测试器械的循环疲劳阻力。在连续旋转和 OTR 运动的往复运动中，Mtwo 和 TF 的循环疲劳性能均显著高于其他器械。
