Transformation behavior of nickel-titanium orthodontic wires under tensile load

Iijima, Masahiro; Ohta, Mitsuru; Brantley, William A.; Naganishi, Atsuko; Murakami, Takashi; Muguruma, Takeshi; Mizoguchi, Itaru

doi:10.4012/dmj.2010-196

Cited by 10 publications

(7 citation statements)

References 25 publications

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“…Nonetheless, the literature review shows that no subsequent studies have followed the ISO 15841:2006 [ 13 , 17 , 20 , 27 , 30 , 32 ], except one study by Brauchli et al [ 24 ]. Hence, this study recommends that all research should follow a single standard procedure with the same parameters (ISO 15841:2006) in order to accurately compare the properties of the different wires reported in the literature.…”

Section: Discussionmentioning

confidence: 99%

Comparison of the superelasticity of different nickel–titanium orthodontic archwires and the loss of their properties by heat treatment

Bellini

Moyano

Gil

et al. 2016

J Mater Sci: Mater Med

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The aim of this work is to describe and compare mechanical properties of eight widely used nickel–titanium orthodontic wires under uniform testing conditions and to determine the influence of the heat treatments on the loss of the superelasticity. Ten archwires from two batches from eight different manufacturers were evaluated. A three-point bending test was performed, in accordance with ISO 15841:2006, on 80 round nickel–titanium archwire segments of 0.016 inch. To obtain a load-deflection curve, the centre of each segment was deflected to 3.1 mm and then unloaded until force became zero. On the unloading curve, deflection at the end of the plateau and forces delivered at that point, and at 3, 2, 1 and 0.5 mm of deflection, were recorded. Plateau slopes were calculated from 3 and from 2 mm of deflection. Data obtained were statistically analysed to determine inter-brand, intra-brand and inter-batch differences (P < 0.05). The results show that at 2 mm of deflection, maximum differential force exerted among brands [Nitinol SuperElastic (1.999N)—Sentalloy M (1.001 N)] was 0.998 N (102 gf). The Nitinol SuperElastic plateau slope (0.353 N/mm) was the only one that was statistically different from 2 mm of deflection, as compared with the other brand values (0.129–0.155 N/mm). Damon Optimal Force described the gentlest slope from 3 mm of deflection (0.230 N/mm) and one of the longest plateaus. Titanol and Orthonol showed the most notable intra-brand differences, whereas inter-batch variability was significant for Nitinol (Henry Schein), Euro Ni–Ti and Orthonol. Superelasticity degree and exerted forces differed significantly among brands. Superelasticity of Nitinol SuperElastic was not observed, while Damon Optimal Force and Proclinic Ni–Ti Superelástico (G&H) showed the most superelastic curves. Intra-brand and inter-batch differences were observed in some brands. In all cases, the heat treatment at 600 °C produces precipitation in the matrix. The precipitates are rich in titanium and this fact produce changes in the chemical composition of the matrix and the loss of the superelasticity. At 400 °C these precipitates are not produced and the forces delivered by the wires are very similar with wires untreated.

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Section: Discussionmentioning

confidence: 99%

Comparison of the superelasticity of different nickel–titanium orthodontic archwires and the loss of their properties by heat treatment

Bellini

Moyano

Gil

et al. 2016

J Mater Sci: Mater Med

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show abstract

“…This method, adopted in this study, allows comparison with results of other studies with similar methodology 3,4,6,7,13,14,16,20 .…”

Section: Discussionmentioning

confidence: 99%

“…With the increase in temperature, the martensitic transition in austenite is initiated at temperature As (Austenite start) and finalized at Af (Austenite finish), when the NiTi alloy is totally austenitic, recovering its shape and acquiring maximum rigidity 6,14,22 . As a response to the temperature variation, the crystalline structure presents deformations in the molecular arrangement, without changes in the atomic composition 3 .…”

Section: Introductionmentioning

confidence: 99%

Transition temperature range of thermally activated nickel-titanium archwires

Spini¹,

Valarelli²,

Cançado³

et al. 2014

J. Appl. Oral Sci.

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Objectives The shape memory resulting from the superelasticity and thermoelastic effect is the main characteristic of thermally activated NiTi archwires and is closely related to the transition temperature range (TTR). The aim of this study was to evaluate the TTR of thermally activated NiTi archwires commercially available. Material and Methods Seven different brands of 0.019"x0.025" thermally activated nickel-titanium archwires were tested as received by differential scanning calorimetry (DSC) over the temperature range from -100°C to 150°C at 10°C/min. Results All thermally activated NiTi archwires analyzed presented stage transformation during thermal scanning with final austenitic temperature (Af) ranging from 20.39°C to 45.42°C. Three brands of NiTi archwires presented Af close to the room temperature and, this way, do not present properties of shape memory and pseudoelasticity that are desirable in clinical applications. Conclusions The thermally activated NiTi archwires present great variability in the TTR and the elastic parameters of each NiTi archwire should be provided by the manufacturers, to allow achievement of the best clinical performance possible.

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“…9 Differential scanning calorimetry (DSC) is the method used to obtain information about the phases of NiTi wires. 6,9,10 The three-point bending test was used to determine the elastic deflection of the selected wires and evaluate their superelasticity ability. 11 This study aimed to use the DSC technique and a mechanical bending test (i.e., the three-point bending test) to evaluate the process of phase transformation of NiTi orthodontic wires and their forces released on deactivation.…”

Section: Introductionmentioning

confidence: 99%

DSC analysis and evaluation of forces released on deactivation of 0.40-mm (0.016") orthodontic thermo-activated NiTi wires: An in vitro study

Sapata

Gurgel

et al. 2020

J Dent Res Dent Clin Dent Prospects

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Background . This study evaluated the phase transformation of NiTi orthodontic wires and forces they release on deactivation. Methods. The structural phase transformations of the following five thermo-activated nickel-titanium (NiTi) wires were evaluated using differential scanning calorimetry (DSC): Flexy Thermal Sentalloy® (GAC International), NiTi (35ºC) (Eurodonto), Thermo-Plus® (Morelli), FlexyNiTi® Flexy Thermal (35ºC) (Orthometric) and Damon® CuNiTi (35ºC) (ORMCO Corp.). The wires had a cross-section of 0.40 mm (0.016"). In addition, the forces they released were investigated using the three-point bending test. Five arches of each wire were tested using DSC (-20/80ºC at 10ºC/min), and six arches from each wire were sectioned for bending tests. The data were analyzed with ANOVA and post hoc Tukey tests. Pearson’s correlation test was performed between the results yielded by the DSC tests and those by three-point analyses (P=0.05). Results. The DSC analysis showed differences between the NiTi alloys from all the manufacturers, with no differences between the lots of the same brand. ORMCO and Orthometric wires exhibited similar TTR values in cooling (P=0.49), and statistically similar TTR values in heating (P=0.056). The three-point bending test showed different patterns in releasing forces. A correlation was found between the DSC analysis and the three-point bending test results. Conclusion. The higher the temperature transformation was, the larger was the variation of force. All the wires presented higher forces at 3-mm deflection from 155 (±12.3) to 168.1 (±8) cN. The DSC analysis and the three-point bending test showed differences between the NiTi alloys from all the manufacturers.

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Transformation behavior of nickel-titanium orthodontic wires under tensile load

Cited by 10 publications

References 25 publications

Comparison of the superelasticity of different nickel–titanium orthodontic archwires and the loss of their properties by heat treatment

Comparison of the superelasticity of different nickel–titanium orthodontic archwires and the loss of their properties by heat treatment

Transition temperature range of thermally activated nickel-titanium archwires

DSC analysis and evaluation of forces released on deactivation of 0.40-mm (0.016") orthodontic thermo-activated NiTi wires: An in vitro study

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