Pseudoelasticity and thermoelasticity of nickel-titanium alloys: A clinically oriented review. Part II: Deactivation forces

Santoro, Margherita; Nicolay, Olivier; Cangialosi, Thomas J.

doi:10.1067/mod.2001.112447

Cited by 42 publications

(28 citation statements)

References 37 publications

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“…6 The low constant force of nickel titanium springs may be more biologically compatible than the intermittent high forces delivered by elastic chain, 6 which has been found to degrade by up to 50% after 4 weeks of activation. 7 The rate of space closure has been found to be quicker and more consistent with nickel titanium coils than with elastic modules, with no observable differences in final tooth position. 1 Nickel titanium closed coil springs typically are used in 9 mm and 12 mm lengths.…”

Section: Introductionmentioning

confidence: 99%

“…These phase transitions can occur through changes in temperature, known as thermoelasticity. 7,8 More typically, these phase transitions can be stress induced by engaging an archwire in a deflected tooth, or stretching a spring over a hook. Shape memory is evident when a deflected nickel titanium archwire that is engaging significantly rotated teeth attempts to return to its original arch form (martensitic phase).…”

Section: Introductionmentioning

confidence: 99%

“…These properties of nickel titanium have made a significant impact in terms of orthodontic treatment mechanics. [7][8][9] Superelasticity refers to the ability of an alloy to exhibit fairly constant stress values over a large range. In orthodontics, this property would allow a nickel titanium spring to exhibit approximately the same amount of force whether it was stretched a small or a large distance.…”

Section: Introductionmentioning

confidence: 99%

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Forces of Various Nickel Titanium Closed Coil Springs

Maganzini

Wong

Ahmed

2010

The Angle Orthodontist

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Objective: To compare the forces generated by 14 different 9 mm springs supplied by five different companies. Materials and Methods: Five replicates of 14 different 9 mm springs were evaluated, resulting in 70 total specimens. Each was extended once from its resting length to 12 mm and then was deactivated. All tests were performed in a 37ЊC water bath. Forces were recorded at the 12 mm extension and deactivation distances of 9 mm, 6 mm, 3 mm, and 1 mm using an MTS force gauge. Data were collected with Testworks software, version 4.0, and were analyzed by analysis of variance (ANOVA) with one factor alternated. Results: Mean peak load forces at 12 mm were significantly different between springs, and these forces varied from 147 to 474 grams. Mean unload forces measured at 9 mm, 6 mm, and 3 mm of deactivation values were highly variable, and only 6 of the 14 springs exhibited a ''physiologic'' mean unload force of 50 grams or less over the total deactivation range. Conclusions: Few springs tested exhibited physiologic peak load forces and constant deactivation forces. This study suggests that labeling of nickel titanium closed coil springs is confusing and misleading. (Angle Orthod. 2010;80:182-187.)

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Forces of Various Nickel Titanium Closed Coil Springs

Maganzini

Wong

Ahmed

2010

The Angle Orthodontist

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“…Horizontal deflections of 0.014-in NiTi wires were standardized at 4 mm with the purpose of enabling them to reach full superelastic regime, since NiTi archwire deflections around 2 mm may be insufficient to bring out the superelastic properties of archwires. 11,9 In order to assess the actual orthodontic forces and friction applied to teeth, in vitro studies using an active configuration must reproduce the actual interbracket distances. 11 A 15 mm distance was adopted between bracket centers that act as support for deflection in the canine region because this corresponds to the average distance between lateral incisor and maxillary first premolars.…”

Section: Discussionmentioning

confidence: 99%

Comparative study of frictional forces generated by NiTi archwire deformation in different orthodontic brackets: In vitro evaluation

Queiroz¹,

Ballester²,

Paiva³

et al. 2012

Dental Press J. Orthod.

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Introduction:The purpose of this study was to compare the frictional forces between 0.014-in NiTi wires (Aditek) with 4 mm horizontal deflection and brackets with different archwire ligation systems. Methods:Four types of self-ligating brackets (Damon MX, Easy Clip, Smart Clip and In-Ovation), a triple bracket (Synergy) and a twin bracket with 8-shaped ligature (Tecnident) were tested. Twin brackets with conventional elastomeric ligatures (Morelli) were used as control group. Tests were repeated 10 times for each bracket/archwire combination. Frictional forces were measured in an Instron universal tensile machine at 3 mm/minute speed and a total displacement of 6 mm. Statistical analysis comprised ANOVA and Dunnett's multiple comparison post hoc test.Results: Deflection-induced frictional (DIF) forces increased in the following order: Synergy, Damon, 8-shaped Ligature, Easy Clip, In-Ovation, Smart-Clip and conventional ligatures. The differences among groups were significant, with the exception of the 8-shaped ligature groups which was equal to the Damon and Easy Clip groups. Conclusions:Compared to conventional ligatures, all ligation systems tested reduced frictional forces. However, such reduction varied according to the ligation system employed.

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“…The test allows the investigating load-deflection properties and friction between wire and bracket. [1516]…”

Section: Introductionmentioning

confidence: 99%

Load-deflection and surface properties of coated and conventional superelastic orthodontic archwires in conventional and metal-insert ceramic brackets

Alavi¹,

Hosseini²

2012

Dent Res J

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Background:Properties of coated archwires, which have been introduced for esthetic demands during orthodontic treatments, along with the use of tooth-colored brackets, are not clear. The aim of this study is to compare the load-deflection and surface properties of coated superelastic archwires with conventional superelastic archwires in conventional and metal-insert ceramic brackets.Materials and Methods:In this experimental study, 3 types of archwires including ultraesthetic polycoated, ultraesthetic epoxyresin coated and conventional (uncoated) superelastic nickel-titanium (NiTi) archwires were used in each of 2 types of brackets including conventional and metal-insert ceramic. To simulate oral environment, all specimens were incubated in artificial saliva using thermocycling model and then were tested in three-bracket bending test machine. Loading and unloading forces, plateau gap and end load deflection point (ELDP) were recorded. Archwires were investigated with a stereomicroscope before and after the experiment. Two-way ANOVA and Tukey tests were used at P<0.05.Results:Epoxyresin archwires produced lower forces (19 to 310 gr) compared to polycoated (61 to 359 gr) and NiTi (61 to 415 gr) (P<0.0001). The maximum ELDP (0.43 mm) was observed in epoxyresin archwires (P<0.001). Coatings of some epoxyresin wires were torn and of polycoated wires peeled off. Conventional ceramic bracket produced higher loading forces with polycoated and NiTi archwires and lower unloading forces with all 3 types of archwires compared to metal-insert type (P<0.05).Conclusion:Epoxyresin-coated archwire had the lowest force and highest ELDP. Coatings were not durable in these experimental conditions. Conventional ceramic bracket produced higher frictional force compared to metal-insert type.

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Pseudoelasticity and thermoelasticity of nickel-titanium alloys: A clinically oriented review. Part II: Deactivation forces

Cited by 42 publications

References 37 publications

Forces of Various Nickel Titanium Closed Coil Springs

Forces of Various Nickel Titanium Closed Coil Springs

Comparative study of frictional forces generated by NiTi archwire deformation in different orthodontic brackets: In vitro evaluation

Load-deflection and surface properties of coated and conventional superelastic orthodontic archwires in conventional and metal-insert ceramic brackets

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