Introduction: New designs and alloys and different motions have been introduced to increase the cyclic fatigue (CF) resistance of nickel-titanium (NiTi) files. The aim of this study was to compare the CF resistance of K3 (SybronEndo, Orange, CA), K3XF (SybronEndo), and TF (SybronEndo) files under continuous rotation and reciprocating motion.
Methods: A total of 210 files (30-tip diameter, 0.06 fixed taper), 60 K3, 60 K3XF, and 90 TF files, were divided into 7 groups (30 files each): K3-C, K3XF-C, and TF1-C were rotated at 300 rpm; TF2-C was rotated at 500 rpm; and K3-R, K3XF-R, and TF1-R were used in a reciprocating motion. CF resistance was tested in stainless steel, curved canals (60°, r = 3 mm) until fracture, and the time to fracture was recorded. The mean half-life, beta, and eta were calculated for each group and were compared with Weibull analysis.
Results: The probability of a longer mean life was greater under reciprocating motion for all of the files (100% for K3, 87% for K3XF, and 99% for TF). Under continuous rotation, K3XF was more resistant than K3 and TF. TF lasted significantly longer than K3. TF was more resistant to CF when rotated at 300 rpm instead of 500 rpm. Under reciprocating motion, there were no significant differences between K3XF and TF mean lives, but both were significantly longer than the K3 mean life (78% for TF and 86% for K3XF).
Conclusions: Reciprocating motion and R-phase increase CF resistance.
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http://dx.doi.org/10.1016/j.joen.2013.07.020 | DOI Listing |
Bioinspir Biomim
January 2025
Tsinghua University, Haidian District, Beijing, 100084, P. R. China, Beijing, Beijing, 100084, CHINA.
Efficient propulsion has been a central focus of research in the field of biomimetic underwater vehicles. Compared to the prevalent fish-like reciprocating flapping propulsion mode, the sperm-like helical propulsion mode features higher efficiency and superior performance in high-viscosity environments. Based on the previously developed sperm-inspired robot, this paper focuses on its dynamic modeling and depth control research.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Endodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia.
The preservation of the original configurations of root canals during endodontic preparation is crucial for treatment success. Nickel-titanium (NiTi) rotary systems have been refined to optimize canal shaping while minimizing iatrogenic errors. This study aimed to evaluate and compare the shaping efficacy of the novel R-Motion (RM) and the established WaveOne Gold (WG) systems using micro-computed tomography (micro-CT).
View Article and Find Full Text PDFJ Endod
December 2024
Department of Endodontics, Fluminense Federal University, Niteroi, Brazil.
Introduction: This study aimed to evaluate the mechanical properties of Reciproc, Reciproc Blue, One RECI, and R-Motion, specifically focusing on their flexibility and buckling resistance and to assess their torsional fatigue behavior under 2 different reciprocation angles (150°/30° or 70°/30°).
Methods: A total of 160 instruments (40 per brand) were tested. Flexion and buckling tests were conducted using a Universal testing machine (DL 200 MF).
Phys Rev Lett
December 2024
Ulm University, Institute for Complex Quantum Systems and Center for Integrated Quantum Science and Technology, Albert-Einstein-Allee 11, 89069 Ulm, Germany.
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