Pedulla Eugenio, Corsentino Giacomo, Ambu Emanuele, Rovai Fabio, Campedelli Federico, Rapisarda Silvia, Rosa Giusy LA, Rapisarda Ernesto, Grandini Simone
Department of General Surgery and Surgical-Medical Specialties, University of Catania, Catania , Italy.
Department of Endodontics and Restorative Densitry, University of Siena, Siena, Italy.
Eur Endod J. 2017 Aug 22;2(1):1-6. doi: 10.14744/eej.2017.17012. eCollection 2017.
Different single-file instruments and kinematics have been introduced on the market. It is important to know the cyclic fatigue performance of these instruments in these new kinematics such as reciprocation of Optimum Torque Reverse (OTR) motion. The aim of this study was to evaluate the resistance to cyclic fatigue of F6 SkyTaper and OneShape used in continuous rotation (proper rotation) or in reciprocating OTR motion.
A total of forty-eight nickel-titanium files were tested. Twenty-four instruments of both brands were divided into two groups (n=12) on the basis of the motion tested: continuous rotation (group 1) or reciprocating 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. Data were analysed by two-way analysis of variance and post-hoc Bonferroni tests for multiple comparisons with P<0.05 as the level of significance.
F6 SkyTaper showed higher TtF compared with OneShape, both in continuous and in OTR motion (P<0.0001). The two tested instruments showed higher cyclic fatigue resistance in reciprocating OTR motion than continuous rotation (P<0.0001).
OTR motion significantly improves cyclic fatigue resistance of the tested instruments. In addition, F6 SkyTaper showed higher cyclic fatigue resistance than OneShape in both motions.
市场上已推出多种单根管器械及运动方式。了解这些器械在诸如最佳扭矩反向（OTR）运动往复等新运动方式下的循环疲劳性能很重要。本研究的目的是评估F6 SkyTaper和OneShape在连续旋转（正旋转）或OTR往复运动中对循环疲劳的抵抗能力。
共测试了48根镍钛锉。两个品牌的24根器械根据测试的运动方式分为两组（n = 12）：连续旋转组（第1组）或OTR往复运动组（第2组）。通过记录在曲率为60°、曲率半径为5 mm的不锈钢人工根管中折断时间（TtF）来确定对循环疲劳的抵抗能力。数据采用双向方差分析和事后Bonferroni检验进行多重比较分析，以P < 0.05作为显著性水平。
在连续旋转和OTR运动中，F6 SkyTaper的TtF均高于OneShape（P < 0.0001）。两种测试器械在OTR往复运动中的循环疲劳抵抗能力均高于连续旋转（P < 0.0001）。
OTR运动显著提高了测试器械的循环疲劳抵抗能力。此外，在两种运动方式下，F6 SkyTaper的循环疲劳抵抗能力均高于OneShape。
