Comparison of Horizontal and Vertical Deactivation Force, Length and Superelasticity in Three Commercial NiTi Orthodontic Archwires

2014 ◽  
Vol 1025-1026 ◽  
pp. 330-335 ◽  
Author(s):  
Surachai Dechkunakorn ◽  
Niwat Anuwongnukroh ◽  
Nuntinee Nanthavannich ◽  
Subongkoch Tongkoom
Keyword(s):  
Cross Section ◽  
Descriptive Analysis ◽  
Nickel Titanium ◽  
Vertical Dimension ◽  
Oral Temperature ◽  
Niti Wire ◽  
Bending Tests ◽  
Three Point Bending ◽  
Horizontal Dimension ◽  
Orthodontic Archwires

Objectives: The aim of this study was to investigate and to compare the deactivation force, deactivation length and superelasticity in horizontal and vertical directions of Nickel-titanium (NiTi) orthodontic archwires made by 3 different manufactures. Materials and methods: The archwires tested were NiTi-OR (Ormco), NiTi-GH (G&H) and NiTi-H (Highland) and were 0.016 x 0.022 inch2in cross-section and 25 mm in length. The study analysed load-deflection curves from three-point bending tests performed for each type of NiTi wire in vertical (occluso-gingival) direction (0.022” in horizontal dimension) and horizontal (bucco-lingual) direction (0.016” in vertical dimension) at oral temperature (37±10oC). Statistical Analysis: Descriptive analysis and Kruskal Wallis test were performed to assess differences in deactivation force, deactivation length and superelasticity among the three brands. A p<0.05 was considered as significant. Results: The deactivation forces ranked from low to high were NiTi-GH, NiTi-OR and NiTi-H, 2.09, 2.57 and 2.90 N, respectively in horizontal dimension (occluso-gingival direction) and 3.04, 3.54 and 3.62 N in vertical dimension (bucco-lingual direction), respectively. For the deactivation length, ranking from long to short were NiTi-GH, NiTi-OR and NiTi-H, 1.08, 1.02 and 0.63 mm in horizontal dimension and 1.63, 1.46 and 1.13 mm in vertical dimension, respectively. In regards to superelasticity, NiTi-OR showed the highest superelasticity, 15.37 in horizontal and 9.68 in vertical dimension, followed by NiTi-GH, 9.51 for horizontal and 6.40 for vertical dimension and NiTi-H, 4.12 for horizontal dimension and 2.96 for vertical dimension. Conclusion: Deactivation force was higher in vertical than horizontal dimension and deactivation length was longer in vertical than horizontal dimension. However, the superelasticity was higher in horizontal than vertical dimension, except NiTi-H. The high priced NiTi wire (NiTi-OR) had the most superelasticity following by medium (NiTi-GH) and low priced wires (NiTi H).

scholarly journals EVALUATION OF THE MECHANICAL PROPERTIES AND SURFACE TOPOGRAPHY OF AS-RECEIVED, IMMERSED AND AS-RETRIEVED ORTHODONTIC ARCHWIRES

2017 ◽  
Vol 90 (3) ◽  
pp. 313-326
Author(s):  
Silvia Izabella Pop ◽  
Mircea Dudescu ◽  
Violeta Valentina Merie ◽  
Mariana Pacurar ◽  
Cristina Dana Bratu
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Stainless Steel ◽  
Tensile Testing ◽  
Nickel Titanium ◽  
Bending Tests ◽  
Three Point Bending ◽  
Beta Titanium ◽  
Carbonated Drinks ◽  
Orthodontic Archwires

Background and aims. This experimental study mainly aims at comparing the most important mechanical properties of the new orthodontic archwires, those immersed in fluorinated solution, the as-retrieved ones and  the intra-oral used ones.Methods. A total of 270 arch wires were tested, using tensile testing and three-point bending tests. The tested archwires were made of Stainless Steel, Nickel Titanium, Beta-Titanium and physiognomic covered Nickel Titanium. The tested archwires were subjected to three types of treatments: immersion into fluorinated solution, immersion into carbonated drinks and intra-oral use.Results. The immersion caused variations of the activation and deactivation forces of all arch wires. The most affected arch wires, in terms of bending characteristics,  were the intra-oral used ones.Conclusions. The alteration of mechanical properties of the orthodontic arch wires by their immersion into fluorinated solutions and soft drinks could not be statistically demonstrated.

Mechanical properties of several nickel-titanium alloy wires in three-point bending tests

1999 ◽  
Vol 115 (4) ◽  
pp. 390-395 ◽  
Author(s):  
Hirokazu Nakano ◽  
Kazuro Satoh ◽  
Robert Norris ◽  
Tomoaki Jin ◽  
Tetsuya Kamegai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Nickel Titanium ◽  
Bending Tests ◽  
Three Point Bending

scholarly journals Experimental study of Young modulus of Attacus atlas, Vespa crabro, and Libellula depressa wings

2018 ◽  
Author(s):  
Michal Landowski ◽  
Zuzanna Kunicka-Kowalska ◽  
Krzysztof Sibilski
Keyword(s):  
Cross Section ◽  
Testing Machine ◽  
Young Modulus ◽  
Air Humidity ◽  
Bending Tests ◽  
Three Point Bending ◽  
Percentage Decrease ◽  
Vespa Crabro ◽  
The Moment ◽  
Do So

AbstractThis paper describes a scientific research aimed at obtaining data for determining Young modulus of the wings of selected insects’ species. A small testing machine intended for three-point bending and equipped with instruments registering low forces was constructed for the needs of the experiment. The machine was used to perform numerous bending tests of wings of three species of insects (obtained from a breeding farm): Attacus atlas, Vespa crabro, Libellula depressa in various air-humidity conditions. Values of the force and displacement obtained in the course of the tests were used to calculate Young modulus. In order to do so, it was also necessary to obtain the moment of inertia of the wing cross-section. These values were measured on the basis of the images obtained with a SEM microscope. Obtained results were averaged and presented with a breakdown by air-humidity conditions. It was observed that Young modulus decreased with an increase of humidity; hence the calculations of the percentage decrease of this mechanical parameter were performed. Obtained results were compared with the observed structure which was also presented under light microscope. It transpired that the construction of a wing does not only influence the mechanical values but also it influences their susceptibility to the changes occurring in the environment. Thereby, differences between Lepidoptera and Hymenoptera insects were indicated also within the aspect discussed in this paper.

Mechanical Properties of Curved Nickel-Titanium Orthodontic Archwires Prepared by Cold Bending and Heat Bending Techniques

2017 ◽  
Vol 266 ◽  
pp. 245-251 ◽  
Author(s):  
Kanuengnit Pongpat ◽  
Surachai Dechkunakorn ◽  
Niwat Anuwongnukroh ◽  
Anak Khantachawana
Keyword(s):  
Mechanical Properties ◽  
Surface Hardness ◽  
Nickel Titanium ◽  
Open Bite ◽  
Bending Test ◽  
Niti Wire ◽  
Cold Forming ◽  
Deep Bite ◽  
Cold Bending ◽  
Orthodontic Archwires

Curved nickel-titanium (NiTi) orthodontic archwires are widely used in deep bite and open bite correction because of their extraordinary properties of shape memory and superelasticity. The aim of this study were to investigate the mechanical properties of curved NiTi archwires prepared by two different techniques; cold bending and direct electric resistance heat treatment (DERHT) bending and compare those properties to preformed curve NiTi archwires. Preformed curve archwires, 0.016x0.022 inch, were served as a control (group1). Plain archwires were curved into similar geometry as control by fingers (group2) and under the application of DERHT (group3). The three-point bending test was performed to analyze unloading force, springback and stiffness of archwires. Surface hardness was measured by Vickers micro-hardness test. The result showed that the unload force of all sample groups were similar. However, the stiffness and spring back properties of group2 and group3 were significantly higher than those of group 1(p<0.05). Moreover, surface hardness of cold forming technique and preform-curved NiTi archwire was slightly lower than those obtained from DERHT bending technique. Based on these results, the cold bending technique could provide the curved archwire with similar mechanical properties to the preform-curved NiTi archwire. Therefore, the cold bending technique was acceptable to be used as a chair-side orthodontic NiTi wire bending.

scholarly journals Friction between Archwires of Different Sizes, Cross-Section and Alloy and Brackets Ligated with Low-Friction or Conventional Ligatures

2009 ◽  
Vol 79 (1) ◽  
pp. 111-116 ◽  
Author(s):  
Simona Tecco ◽  
Stefano Tetè ◽  
Felice Festa
Keyword(s):  
Stainless Steel ◽  
Ambient Temperature ◽  
Cross Section ◽  
Null Hypothesis ◽  
Frictional Resistance ◽  
Nickel Titanium ◽  
Molybdenum Alloy ◽  
Low Friction ◽  
Significant Difference ◽  
Orthodontic Archwires

Abstract Objective: To test the null hypothesis that no statistically significant difference in frictional resistance is noted when round or rectangular archwires are used in conjunction with low-friction ligatures (small, medium, or large) or conventional ligatures. Materials and Methods: A total of 10 stainless steel brackets, a 0.022-in slot, and various orthodontic archwires, ligated with low-friction ligatures or conventional ligatures, were tested to compare frictional resistance. The archwires employed were 0.014-in and 0.016-in nickel titanium (NiTi), 0.018-in stainless steel (SS), 0.016 × 0.022-in NiTi, 0.016 × 0.022-in SS, 0.017 × 0.025-in titanium molybdenum alloy (TMA), 0.017 × 0.025-in NiTi, 0.017 × 0.025-in SS, 0.019 × 0.025-in SS, and 0.019 × 0.025-in NiTi. Each bracket/archwire combination was tested 10 times in the dry state at an ambient temperature of 34°C. Results: Low-friction ligatures with round archwires showed statistically significantly lower frictional resistance than did conventional ligatures. When coupled with 0.016 × 0.022-in NiTi and SS, no statistically significant difference was observed among the four groups. When coupled with 0.017 × 0.025-in archwires, low-friction ligatures showed statistically significantly greater frictional resistance than was seen with conventional ligatures. When coupled with 0.019 × 0.025-in NiTi, low-friction ligatures showed statistically significantly greater frictional resistance than did conventional ligatures, but no difference among the four groups was observed with the 0.019 × 0.025-in SS. No significant difference was assessed among low-friction ligatures of different sizes. Conclusion: Low-friction ligatures show lower friction when compared with conventional ligatures when coupled with round archwires, but not when coupled with rectangular ones.

Effect of Direct Electric Resistance Heat Treatment on Loading/Unloading Behavior of Nickel Titanium Orthodontic Wire

2014 ◽  
Vol 487 ◽  
pp. 135-140 ◽  
Author(s):  
Surachai Dechkunakorn ◽  
Chavarit Sujaritviriyakul ◽  
Niwat Anuwongnukroh ◽  
Nathaphon Tangit
Keyword(s):  
Heat Treatment ◽  
Treatment Method ◽  
Nickel Titanium ◽  
Control Group ◽  
Electric Resistance ◽  
Niti Wire ◽  
Orthodontic Wire ◽  
Loading And Unloading ◽  
The Difference ◽  
Orthodontic Archwires

Objective: The aim of this study was to investigate and compare the loading and unloading characteristics of various nickel-titanium (NiTi) and nickel-titanium-copper (NiTiCu) after direct electric resistance heat treatment method (Bender soarer-X equipment). Materials and Methods: Five types of commercial NiTi and NiTiCu orthodontic archwires [NiTi (W&H), NiTi (Ormco), CuNiTi (Ormco), Sentalloy (Tomy) and L&H (Tomy)] underwent heat treatment by the Bender soarer-X equipment and all samples underwent the three point bending tests to analyze their loading and unloading characteristics. Each type of wire was divided into 6 groups with 10 samples per group with one of the groups serving as non-heat treatment control group. The wire composition was analyzed by energy dispersive spectroscopy (EDS) method. Results: The results showed that the loading and unloading characteristics of W&H NiTi and Ormco NiTi after heat treatment were not significantly different from the non-heat treatment groups. But the Tomy Sentalloy, Tomy L&H and Ormco NiTiCu had significantly different results (p<0.05) after heat treatments. The factors which could affect the loading and unloading characteristics were the difference in alloy composition and the condition of heat treatment. Conclusion: Heat treatment increased the loading and unloading force of Tomy L&H and improved the shape forming ability of NiTi wire.

Effect of Direct Electric Resistance Heat Treatment on Mechanical Properties of NiTi Orthodontic Arch Wires

2008 ◽  
Vol 55-57 ◽  
pp. 249-252 ◽  
Author(s):  
W. Kiattiwongse ◽  
Anak Khantachawana ◽  
P. Santiwong
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Bending Test ◽  
Electric Resistance ◽  
Bending Tests ◽  
Three Point Bending ◽  
Heat Treated ◽  
Different Types ◽  
Orthodontic Archwires ◽  
A Current

Two types of rectangular orthodontic archwires; NiTiTM and 40oCuNiTi, were heat treated by Direct Electric Resistance Heat Treatment (DERHT) using different electric currents for 4 s. Their mechanical properties were then evaluated by micro hardness and three-point bending tests. After applying 4.5-5.5 A current, the hardness of NiTiTM increased with the increased current, whereas the change in hardness of 40oCuNiTi was slight. When 6 A current was applied, the hardness of the midspan of both wires significantly decreased. From the three-point bending test, unloading forces of NiTiTM increased after treating with 5.5 A current, while those of 40oCuNiTi decreased. However, both specimens lost their superelasticity when applied with 6 A current. In conclusion, after DERHT, various changes in mechanical properties can be noted in the different types of nickel titanium archwire.

Oxidation Resistance and Bending Strength at High Temperatures of Ni/(ZrO2+Al2O3) Hybrid Materials

2018 ◽  
Vol 922 ◽  
pp. 104-109
Author(s):  
Hai Vu Pham ◽  
Makoto Nanko ◽  
Wataru Nakao
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Cross Section ◽  
High Temperatures ◽  
Room Temperature ◽  
Bending Strength ◽  
Bending Tests ◽  
Three Point Bending ◽  
Order Of Magnitude ◽  
Zone Development

Oxidation resistance and bending strength at high temperatures of 5 vol% Ni/(10 vol% ZrO2+Al2O3) were investigated in this paper. Oxidation tests were conducted at temperature ranging from 1100 to 1300oC for 1 to 24 h in air. The oxidation resistance of the composites was studied via observation of oxidized-zone development from a cross-section view after oxidation. Three-point bending tests were conducted at temperatures ranging from room temperature to 1200oC in order to estimate its performance at high temperatures. Bending strength of the composites achieved 1200 MPa at room temperature and 460 MPa at 1200oC. Dispersion of ZrO2in Ni/Al2O3composites enhanced both their room and high temperature bending strength. Nevertheless, ZrO2slightly degraded the oxidation resistance of the composites. The oxidation rate of Ni/(ZrO2+Al2O3) was one order of magnitude higher than that of Ni/Al2O3.

Mechanical Properties of Several NiTi Alloy Wires in Three-Point Bending Tests

2011 ◽  
Vol 87 ◽  
pp. 14-19 ◽  
Author(s):  
Surachai Dechkunakorn ◽  
Rutchadakorn Isarapatanapong ◽  
Niwat Anuwongnukroh ◽  
Nattiree Chiranavanit ◽  
Julathep Kajorchaiyakul ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Niti Alloy ◽  
Bending Test ◽  
Dental Arch ◽  
Orthodontic Wires ◽  
Niti Wire ◽  
Bending Tests ◽  
Three Point Bending ◽  
Loading And Unloading ◽  
Deflection Rate

Objective: To clarify mechanical properties of 14 superelastic NiTi orthodontic wires by three-point bending tests. Materials and Methods: The three-point bending test was conducted with a midspan deflection rate of 5 mm/min under constant temperature range 36±1°C. Wires were deflected to 3.1 mm. All data were recorded during the unloading process at deflections 3, 2, 1 and 0.5 mm. to simulate the force a wire exerts as a tooth is moved into the dental arch from a position of malocclusion. Results: The delivered forces changed slightly when the deflection varied during loading and unloading. Sentalloy wire applied the lowest continuous force. Conclusions: Commercial wires may not behave similarly due to minor differences in the production process, and force varies greatly from brand to brand. NiTi wire brands must be selected carefully considering the severity of malocclusion and stage of orthodontic treatment.

Investigation of the Deformation Twins on the Bending Cross Section of TA2 Titanium Sheet

2020 ◽  
Vol 837 ◽  
pp. 41-45
Author(s):  
Shuai Sun ◽  
Kai Hua Liu
Keyword(s):  
Electron Backscatter Diffraction ◽  
Testing Machine ◽  
Pure Titanium ◽  
Titanium Sheet ◽  
Bending Tests ◽  
Three Point Bending ◽  
Deformation Twins ◽  
Ebsd Technique ◽  
Backscatter Diffraction ◽  
Deformation Area

In order to determine the evolution features of deformation twins for TA2 commercial pure titanium (cp-TA2), the TA2 samples were bent under different bending angles in three-point bending tests via a universal testing machine. The electron backscatter diffraction (EBSD) technique was applied to identify the grain boundaries (GBs) and twin boundaries (TBs) in the bending areas. The results reveal that the type of deformation area would effect the evolution of different deformation twins. It is inferred that the state of stress would promote the multiplication of the same type of deformation twins.

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