Nogueira Daiane, Bueno Carlos Eduardo Da Silveira, Kato Augusto Shoji, Martin Alexandre Sigrist De, Pelegrine Rina Andréa, Limoeiro Ana Grasiela Da Silva, Rocha Daniel Guimarães Pedro, Fontana Carlos Eduardo
Department of Endodontics São Leopoldo Mandic Dental Research Center, School of Dentistry, Ilhéus, Bahia, Brazil.
Department of Endodontics, School of Dentistry, Ilhéus, Bahia, Brazil.
J Conserv Dent. 2020 Nov-Dec;23(6):554-557. doi: 10.4103/JCD.JCD_117_19. Epub 2021 Feb 11.
It is essential to know if the immersion in sodium hypochlorite (NaOCl) influences the cyclic fatigue resistance of nickel-titaniumm (NiTi) files.
This study was aimed to evaluate the resistance to the cyclic fatigue of three NiTi systems, as well as the influence of 5.25% NaOCl on their resistance.
Files from the Sequence Rotary File (MK life, Porto Alegre, Brazil), ProTaper Next (PTN) (Dentsply, Maillefer, Baillagues, Switzerland), and HyFlex EDM (Coltène Whaledent, Allstatten, Switzerland) systems were tested and separated into Group 1)-without immersion in NaOCl solution and Group 2 and Group 3-immersed in 5.25% NaOCl solution, for 1 min, and 5 min, respectively. All instruments were submitted to the cyclic fatigue test. Images of the instruments were observed by scanning electron microscopy, to evaluate the type of defect presented on the fractured surface. The test performed for the analysis of two independent factors was a two-way analysis of variance.
HyFlex EDM presented a greater number of cycles until fracture when compared to others ( < 0.001). The control group showed a greater number of cycles until fracture than the same instruments submitted to NaOCl ( < 0.001). Sequence instruments showed the lowest values of cycles until fracture ( < 0.001). There was no statistically significant difference between treatments ( = 0.998). PTN, showed intermediate values of fracture resistance when compared to the HyFlex EDM and sequence instruments ( < 0.001), but without intragroup differences ( = 0.437).
Hyflex EDM instruments were the most resistant to cyclic fatigue.
了解镍钛（NiTi）锉浸入次氯酸钠（NaOCl）中是否会影响其抗循环疲劳性能至关重要。
本研究旨在评估三种NiTi系统的抗循环疲劳性能，以及5.25% NaOCl对其抗疲劳性能的影响。
对来自Sequence Rotary File（MK life，巴西阿雷格里港）、ProTaper Next（PTN）（登士柏，瑞士拜勒格的Maillefer公司）和HyFlex EDM（瑞士阿尔施泰滕的Coltène Whaledent公司）系统的锉进行测试，并分为1组（不浸入NaOCl溶液）、2组和3组（分别浸入5.25% NaOCl溶液1分钟和5分钟）。所有器械均进行循环疲劳测试。通过扫描电子显微镜观察器械的图像，以评估断裂表面出现的缺陷类型。用于分析两个独立因素的测试是双向方差分析。
与其他系统相比，HyFlex EDM在断裂前的循环次数更多（<0.001）。对照组在断裂前的循环次数比浸入NaOCl的相同器械更多（<0.001）。Sequence器械在断裂前的循环次数最低（<0.001）。不同处理之间无统计学显著差异（=0.998）。与HyFlex EDM和Sequence器械相比，PTN的抗断裂性能处于中间值（<0.001），但组内无差异（=0.437）。
Hyflex EDM器械对循环疲劳的耐受性最强。
