scholarly journals Deflecting load of nickel titanium rotary instruments during cyclic fatigue

2012 ◽  
Vol 31 (3) ◽  
pp. 389-393 ◽  
Author(s):  
Ahmed JAMLEH ◽  
Chihiro KOBAYASHI ◽  
Yoshio YAHATA ◽  
Arata EBIHARA ◽  
Hideaki SUDA
Keyword(s):  
Cyclic Fatigue ◽  
Nickel Titanium ◽  
Rotary Instruments

scholarly journals Automatic Electronic Device Used for the Evaluation of Cyclic-Fatigue Resistance of Nickel-Titanium Instruments

2017 ◽  
Vol 19 (1) ◽  
pp. 51
Author(s):  
Cesar Gaitán-Fonseca DDS, MSc, PhD ◽  
Edith Lara-Alvarado DDS, MSc ◽  
Héctor Flores-Reyes DDS, MSc, PhD ◽  
Amaury Pozos-Guillén DDS, MSc, PhD ◽  
Verónica Méndez-González DDS, MSc
Keyword(s):  
Human Factor ◽  
Electronic Device ◽  
Cyclic Fatigue ◽  
Nickel Titanium ◽  
Cycle Number ◽  
Fracture Pressure ◽  
Group Data ◽  
Rotary Instruments ◽  
Two Parameters ◽  
Pressure Changes

The aim of this study was to evaluate the cyclic-fatigue fracture of different Nickel-Titanium motor-driven rotary instruments (ProTaper® Universal, ProFile®, and Mtwo® systems) in artificial canals by means of an Automatic Electronic Device (AED). The study was performed using Nickel-Titanium instruments 25/0.06 evaluated in canals with a 45-degree curvature and 2-mm radius. The analyses evaluated two parameters: fracture by cyclic fatigue, and time of fracture; in addition, the length of separated fragment was evaluated. Medians and range values were calculated for each group. Data were analyzed by the Kruskall–Wallis and Mann–Whitney U tests to determine statistical difference. The ProFile motor-driven rotator system exhibited highest resistance to fracture due to cyclic fatigue and highest fracture time compared with the ProTaper and Mtwo systems (p <0.05). The equipment proposed in this study (AED) demonstrated efficiency for recording information, automation, scheduled work times and durations, cycle number, time of fracture, pressure changes and, principally control of the human factor.

scholarly journals An Update on Nickel-Titanium Rotary Instruments in Endodontics: Mechanical Characteristics, Testing and Future Perspective—An Overview

2021 ◽  
Vol 8 (12) ◽  
pp. 218
Author(s):  
Alessio Zanza ◽  
Maurilio D’Angelo ◽  
Rodolfo Reda ◽  
Gianluca Gambarini ◽  
Luca Testarelli ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Mechanical Characteristics ◽  
State Of The Art ◽  
Cyclic Fatigue ◽  
Nickel Titanium ◽  
Future Perspective ◽  
Current State ◽  
Rotary Instruments ◽  
Torsional Loads

Since the introduction of Nickel-Titanium alloy as the material of choice for the manufacturing of endodontic rotary instruments, the success rate of the root canal therapies has been significantly increased. This success mainly arises from the properties of the Nickel-Titanium alloy: the biocompatibility, the superelasticity and the shape memory effect. Those characteristics have led to a reduction in time of endodontic treatments, a simplification of instrumentation procedures and an increase of predictability and effectiveness of endodontic treatments. Nevertheless, the intracanal separation of Nickel-Titanium rotary instruments is still a major concern of endodontists, with a consequent possible reduction in the outcome rate. As thoroughly demonstrated, the two main causes of intracanal separation of endodontic instruments are the cyclic fatigue and the torsional loads. As results, in order to reduce the percentage of intracanal separation research and manufacturers have been focused on the parameters that directly or indirectly influence mechanical properties of endodontic rotary instruments. This review describes the current state of the art regarding the Nickel-Titanium alloy in endodontics, the mechanical behavior of endodontic rotary instruments and the relative stresses acting on them during intracanal instrumentation, highlighting the limitation of the current literature.

scholarly journals Influence of nickel-titanium rotary systems with varying cross-sectional, pitch, and rotational speed on deflection and cyclic fatigue: a finite element analysis study

2021 ◽  
Vol 41 ◽  
pp. 05005
Author(s):  
Wignyo Hadriyanto ◽  
Lukita Wardani ◽  
Christina Nugrohowati ◽  
Ananto Alhasyimi ◽  
Rachmat Sriwijaya ◽  
...  
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Rotational Speed ◽  
Cyclic Fatigue ◽  
Nickel Titanium ◽  
Element Analysis ◽  
Cross Sectional ◽  
Rotary Instruments ◽  
Section Design ◽  
Sectional Shape

The effectiveness of endodontic file preparation depends, among others, on the material, geometric shape, and the drive system. This study aimed to analyze the effect of cross-sectional, pitch, and rotational speed on cyclic fatigue and deflection of NiTi files using finite element analyses. A total of 18 NiTi endodontic rotary instruments ProTaper Gold F2 #25.08 and Hyflex CM #25.04 (n=9) modeling were designed using Autodesk software. Subjects were divided into two groups, the design group of square and convex triangles. Static simulation was then carried out to each group with force on the instrument’s tip by 1N, 2N, and 3N. The file’s cycling fatigue was analyzed at rotating speeds of 200 rpm, 300 rpm, and 400. The data were analyzed by using the three-way Analysis of variance (ANOVA) test followed by LSD (p< 0.05). The results showed the cross-sectional shape and force effect on the deflection value and cyclic fatigue received by the endodontic files (p< 0.05). The convex triangle design presented the lowest cyclic fatigue than square. The convex triangular cross-section design showed a higher deflection value than the square cross-section design.

scholarly journals Role of the Flat-Designed Surface in Improving the Cyclic Fatigue Resistance of Endodontic NiTi Rotary Instruments

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2523 ◽  
Author(s):  
Gianluca Gambarini ◽  
Gabriele Miccoli ◽  
Marco Seracchiani ◽  
Tatyana Khrenova ◽  
Orlando Donfrancesco ◽  
...  
Keyword(s):  
Cyclic Fatigue ◽  
Nickel Titanium ◽  
Segment Length ◽  
Flat Side ◽  
Heat Treated ◽  
Rotary Instruments ◽  
Time To Fracture ◽  
Niti Instruments ◽  
Niti Rotary Instruments

The aim of this study was to investigate the role of the flat-designed surface in improving the resistance to cyclic fatigue by comparing heat-treated F-One (Fanta Dental, Shanghai, China) nickel–titanium (NiTi) rotary instruments and similar prototypes, differing only by the absence of the flat side. The null hypothesis was that there were no differences between the two tested instruments in terms of cyclic fatigue lifespan. A total of 40 new NiTi instruments (20 F-One and 20 prototypes) were tested in the present study. The instruments were rotated with the same speed (500 rpm) and torque (2 N) using an endodontic motor (Elements Motor, Kerr, Orange, CA, USA) in the same stainless steel, artificial canal (90° angle of curvature and 5 mm radius). A Wilcoxon–Mann–Whitney test was performed to assess the differences in terms of time to fracture and the length of the fractured segment between the flat- and non-flat-sided instruments. Significance was set at p = 0.05. The differences in terms of time to fracture between non-flat and flat were statistically significant (p < 0.001). In addition, the differences in terms of fractured segment length were statistically significant (p = 0.034). The results of this study highlight the importance of flat-sided design in increasing the cyclic fatigue lifespan of NiTi rotary instruments.

Cyclic fatigue resistance of new and used ProTaper universal and ProTaper next nickel-titanium rotary instruments

2018 ◽  
Vol 8 (2) ◽  
pp. 82 ◽  
Author(s):  
Taha Özyürek ◽  
NeslihanBüşra Keskin ◽  
Gülşah Uslu ◽  
Uğur İnan
Keyword(s):  
Fatigue Resistance ◽  
Cyclic Fatigue ◽  
Nickel Titanium ◽  
Rotary Instruments
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