scholarly journals Torsional Resistance of Two New Heat Treated Nickel Titanium Rotary Instruments: An in Vitro Evaluation

2020 ◽  
Vol 20 ◽  
Author(s):  
Gianluca Gambarini ◽  
Gabriele Miccoli ◽  
Dario Di Nardo ◽  
Andrea Del Giudice ◽  
Alessandro Mazzoni ◽  
...  
Keyword(s):  
Nickel Titanium ◽  
In Vitro Evaluation ◽  
Torsional Resistance ◽  
Heat Treated ◽  
Rotary Instruments

scholarly journals Nickel–Titanium Rotary Instruments: An In Vitro Comparison (Torsional Resistance of Two Heat-treated Reciprocating Files)

2021 ◽  
Vol 22 (4) ◽  
pp. 361-364
Author(s):  
Shilpa Bhandi ◽  
Gianluca Gambarini ◽  
Marco Seracchiani ◽  
Luca Testarelli ◽  
Alessandro Mazzoni ◽  
...  
Keyword(s):  
Nickel Titanium ◽  
Torsional Resistance ◽  
Heat Treated ◽  
Rotary Instruments ◽  
In Vitro Comparison

scholarly journals Torsional Resistance of Heat-Treated Nickel-Titanium Instruments under Different Temperature Conditions

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5295
Author(s):  
Hyo Jin Jo ◽  
Sang Won Kwak ◽  
Hyeon-Cheol Kim ◽  
Sung Kyo Kim ◽  
Jung-Hong Ha
Keyword(s):  
Nickel Titanium ◽  
Phase Transformation Temperature ◽  
Scanning Calorimetry ◽  
Temperature Conditions ◽  
Torsional Resistance ◽  
Heat Treated ◽  
Rotary Instruments ◽  
Single Use ◽  
Niti Instruments ◽  
Niti Rotary Instruments

This study compared the torsional resistance of heat-treated nickel-titanium (NiTi) instruments under different temperature conditions. Four thermomechanically treated single-use NiTi rotary instruments were selected for this study: OneShape (OS), OneCurve (OC), WaveOne Gold (WOG) and HyFlex EDM (HFE). Each instrument was further subdivided by temperature into 2 subgroups. Maximum torque and the distortion angle until fracture occurred were evaluated. Differential scanning calorimetry analysis was performed to measure the phase transformation temperature. Statistical analysis was performed using a two-way ANOVA and t-test (p < 0.05). Fractured fragments were observed using scanning electron microscopy (SEM). The two-way ANOVA showed no significant differences for different temperature conditions. At both room (RT) and body temperature (BT), OS was predominantly austenite while HFE was martensite. OC and WOG were predominantly martensite at RT and mixed phase at BT. At BT, more than half of WOG was martensite, while half of OC was austenite. SEM examination showed no topographical differences between instruments in different temperature groups. In relation to a limitation of this study, there was no difference in torsional resistance of NiTi rotary instruments between the BT and RT conditions. This implies that clinicians do not need to consider a decrease of torsional resistance of heat-treated NiTi instruments at BT.

scholarly journals Influence of Different Heat Treatments on Torsional and Cyclic Fatigue Resistance of Nickel–Titanium Rotary Files: A Comparative Study

2020 ◽  
Vol 10 (16) ◽  
pp. 5604 ◽  
Author(s):  
Gianluca Gambarini ◽  
Andrea Cicconetti ◽  
Dario Di Nardo ◽  
Gabriele Miccoli ◽  
Alessio Zanza ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Fatigue Resistance ◽  
Cyclic Fatigue ◽  
Sem Analysis ◽  
Nickel Titanium ◽  
Torsional Resistance ◽  
Heat Treated ◽  
Torsional Test ◽  
Time To Fracture ◽  
Flexural Resistance

Protaper Universal (PTU), Protaper Gold (PTG) (Maillefer, Ballaigues, CH), EdgeTaper (ET), and EdgeTaper Platinum (ETP) (Albuquerque, NM, USA) were tested for both torsional and flexural resistance. The aim of the present study was to evaluate the influence of proprietary heat treatment on the metallurgical properties of the aforementioned instruments. Four groups of 30 different instruments (size 20.07) were tested, then divided into two subgroups of 15 instruments—one for the cyclic fatigue test in a curved canal (90°—2 mm radius) at 300 rpm and 2.5 Ncm. The time to fracture (TtF) and fragment length (FL) were recorded. The other subgroup was subjected to the torsional test (300 rpm, 5.5 Ncm). The torque to fracture and TtF were recorded. All the instruments underwent a SEM analysis. The heat-treated instruments showed a significantly higher fatigue resistance than the non-heat-treated instruments (p < 0.05). No significant differences were found in the torsional resistance between the ET and PTU, and the ETP and PTG. However, when comparing all the groups, the heat-treated instruments showed less torsional resistance. The improvement from heat treatment was mainly found in the cyclic fatigue resistance.

Comparison of the flexibility and torsional resistance of nickel-titanium rotary instruments

2013 ◽  
pp. 16-22
Author(s):  
Weber Schmidt Pereira Lopes ◽  
Hélio Pereira Lopes ◽  
Carlos Nelson Elias ◽  
Marcelo Mangelli ◽  
Márcia Valéria Boussada Vieira
Keyword(s):  
Nickel Titanium ◽  
Torsional Resistance ◽  
Rotary Instruments

scholarly journals Influence of Axial Movement on Fatigue of Profile® Ni-Ti Rotary Instruments: an in vitro evaluation

2010 ◽  
Vol 10 (2) ◽  
pp. 107-111 ◽  
Author(s):  
Marie-Chantal Avoaka ◽  
Youssef Haïkel
Keyword(s):  
Statistical Difference ◽  
Statistical Evaluation ◽  
Clinical Situation ◽  
Nickel Titanium ◽  
Radius Of Curvature ◽  
Significant Statistical Difference ◽  
Apical Direction ◽  
Rotary Instruments ◽  
Axial Movement

The aim of this study was to evaluate the influence of the axial movement and the angle of curve (in degrees) on fatigue of nickel-titanium (Ni-Ti) ProFile’ rotary endodontic instruments.Ni-Ti ProFile’ rotary instruments (Maillefer SA, Ballaigues, Switzerland), 25 mm long in the range of ISO size 15 to 40 with two tapers (0.4 and 0.6) were evaluated. They are divided in two groups: the instruments with axial movement and those without axial movement. The system used to test the fatigue is maintained in mechanical conditions as close as possible to the clinical situation. The axial movement is in the order of 2mm in corono-apical direction with a frequency of 1Hz. The concave radii incorporating a notched V-form for guiding the instruments were: 5; 7,5 and 10 mm. The rotary system is mounted on an electric handpiece and rotated at 350 rpm speed as recommended by the manufacturers. The instruments are rotated until their separation, and the time, in seconds, is recorded. Statístícal evaluation is undertaken using a two-way t-test to identify significant differences between variables in the study (p <0,05).We found significant statistical difference (p<0,05) between Ni-Ti engine drive ProFile’ instruments incorporating an axial movement and the instruments without axial movement with the same radius of curvature, size and taper.The incorporation of the axial movement increases significantly the life-span of the ProFile’ rotary instruments. This should reduce the risk of the instrument separation during the endodontic treatment

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.

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