scholarly journals Comparative evaluation of mechanical properties and shaping performance of heat-treated nickel titanium rotary instruments used in the single-length technique

Author(s):  
Taro NAKATSUKASA ◽  
Arata EBIHARA ◽  
Shunsuke KIMURA ◽  
Keiichiro MAKI ◽  
Miki NISHIJO ◽  
...  
2017 ◽  
Vol 43 (11) ◽  
pp. 1872-1877 ◽  
Author(s):  
Hye-Jin Goo ◽  
Sang Won Kwak ◽  
Jung-Hong Ha ◽  
Eugenio Pedullà ◽  
Hyeon-Cheol Kim

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5295
Author(s):  
Hyo Jin Jo ◽  
Sang Won Kwak ◽  
Hyeon-Cheol Kim ◽  
Sung Kyo Kim ◽  
Jung-Hong Ha

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.


2008 ◽  
Vol 34 (12) ◽  
pp. 1533-1536 ◽  
Author(s):  
Fabiola Ormiga Galvão Barbosa ◽  
José Antônio da Cunha Ponciano Gomes ◽  
Marcos Cesar Pimenta de Araújo

2011 ◽  
Vol 44 (4) ◽  
pp. 337-341 ◽  
Author(s):  
G. Gambarini ◽  
G. Plotino ◽  
N. M. Grande ◽  
D. Al-Sudani ◽  
M. De Luca ◽  
...  

2013 ◽  
Vol 39 (4) ◽  
pp. 516-520 ◽  
Author(s):  
Hélio P. Lopes ◽  
Thaiane Gambarra-Soares ◽  
Carlos N. Elias ◽  
José F. Siqueira ◽  
Inês F.J. Inojosa ◽  
...  

2018 ◽  
Vol 8 ◽  
pp. 92-95
Author(s):  
Faiz Ahmad Bhat ◽  
Nandish Shetty ◽  
Faizan Ahmad Khan ◽  
Muraleedhara Bhat ◽  
Akhter Husain

Context The tooth alignment and leveling constitute the preliminary clinical phase of any orthodontic procedure with fixed appliances. It has been accepted in orthodontics the principle that light and continuous forces would be desirable for physiologic and controlled tooth movement. For this purpose, it has been suggested that nickel-titanium (NiTi) archwires which offer a force-bending curve with a defined baseline and a larger activation range should be used Aims The aim of this study was to evaluate and compare the force versus deflection properties of different brands of NiTi wires available in market. Settings and Design Null hypothesis. There is no difference in force-deflection properties between different brands of same dimension NiTi archwires available in market. A cross-sectional study design was planned. Subjects and Methods Different companies were identified producing their own version or marketing NiTi archwires of the following sizes: 0.016 inch round and 0.016 × 0.022 inch rectangular were selected because all companies produced or marketed these particular sizes, and in addition, these were selected because these wire sizes are commonly used clinically. The three-point bend test was utilized to test the various wires in accordance with the ISO 15841 standard for orthodontic wires with the exception that the bottom support span was 16 mm rather than 10 mm due to fixture limitations. Statistical Analysis Used Data obtained from different brands of wires available in the Indian market Ormco, American Orthodontics, Ortho Organizers, Rocky Mountain Orthodontics 3M and MO which are manufactured in U.S.A, While as Natural, Orthomatix, JJ Orthodontics, Koden, Gdc, Rabbit force, and Optima are manufactered in china. and size 0.016 inch round wire and 0.16x0.022 inch rectangular wires were compared using ANOVA test. Statistical analysis was performed using SPSS 2.1. Results In this study, the data show that minimum force during activation of 0.016 inch round wire at 1 mm was 95 ± 10 g whereas maximum was 165 ± 10 g with a difference of 70 ± 20 g. Whereas at 3 mm activation, minimum force generated was 150 ± 10 g and maximum was 225 ± 10 g with a difference of 75 ± 20 g. In 0.016 × 0.022 inch rectangular wire, minimum activation force at 1 mm deflection was 210 ± 10, whereas maximum was 340 ± 10 with a difference of 130 ± 20 g. For deactivation, the minimum force for 0.016 wire at 1 mm deflection was 40 ± 10, whereas maximum force was 125 ± 10 with a difference of 85 ± 20 g, and for the 0.016 × 0.022 wire, the minimum load at 1 mm deflection was 150 ± 10 g, whereas the maximum was 295 ± 10 g with a difference of 145 ± 20 g. The deactivation force in majority of brands (8) at 1 mm deflection was <80 g whereas at 3 mm, majority brands have force levels >150–195 g. The deactivation force at 3 mm deflection in five brands was between 235 and 335 and five other brands between 335 and 445 whereas at 1 mm, deflection majority of brands was between 170 and 200 g. Conclusion From this data, a comparative evaluation shows that there is a huge difference in force-deflection properties of same dimension wire from different brands, which means that its making the orthodontic treatment more indeterminate; some wires have shown less and some have shown more force. Wires of the same materials, dimensions, but from different manufacturers do not always have the same mechanical properties. There are significant differences in the activation and deactivation forces among the different manufacturers of NiTi archwires. Improvements should be made in the standardization of the manufacturing testing process of NiTi archwires to provide orthodontists with NiTi archwires that have consistent mechanical properties despite the manufacturing brand that produces them.


2021 ◽  
Vol 22 (4) ◽  
pp. 361-364
Author(s):  
Shilpa Bhandi ◽  
Gianluca Gambarini ◽  
Marco Seracchiani ◽  
Luca Testarelli ◽  
Alessandro Mazzoni ◽  
...  

2021 ◽  
Vol 8 (12) ◽  
pp. 218
Author(s):  
Alessio Zanza ◽  
Maurilio D’Angelo ◽  
Rodolfo Reda ◽  
Gianluca Gambarini ◽  
Luca Testarelli ◽  
...  

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.


2012 ◽  
Vol 3 (6) ◽  
pp. 151 ◽  
Author(s):  
GopalS. Narayan ◽  
SokkalingamMothilal Venkatesan ◽  
C. S. Karumaran ◽  
S. Ramachandran ◽  
M. R. Srinivasan ◽  
...  

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2523 ◽  
Author(s):  
Gianluca Gambarini ◽  
Gabriele Miccoli ◽  
Marco Seracchiani ◽  
Tatyana Khrenova ◽  
Orlando Donfrancesco ◽  
...  

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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