Force degradation of closed coil springs: An in vitro evaluation

Angolkar, Padmaraj V.; Arnold, Janet V.; Nanda, Ram S.; Duncanson, Manville G.

doi:10.1016/0889-5406(92)70024-5

Cited by 46 publications

(45 citation statements)

References 19 publications

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“…This is in agreement with an in vitro study conducted by Angolkar et al that showed an overall 8–20% drop over 28 days in force levels among various metal alloy coil springs. 13 A higher force decay percentage of 48% over a 22 week time period was reported in an in vivo study by Nightingale and Jones, which could be due to the fact that their values were measured with an intra-oral force gauge at the spring stretch lengths and thus likely included both the intrinsic force loss within the spring material itself as well as a large contribution from the fact that the coil spring length had decreased between time measurements due to space closure. 14 However, none of the springs tested in these studies were from the GAC company and since manufacturing conditions play a major role in force properties of these springs, the data is likely not very comparable with our study.…”

Section: Discussionmentioning

confidence: 89%

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In-vivo force decay of nickel-titanium closed-coil springs

Cox¹,

Nguyen²,

Koroluk³

et al. 2014

American Journal of Orthodontics and Dentofacial Orthopedics

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Introduction Nickel-titanium (NiTi) closed coil springs are purported to deliver constant forces over extended ranges of activation and working times. In vivo studies supporting this claim are limited. The objective of this study is to evaluate changes in force decay properties of NiTi closed coil springs after clinical use. Methods Pseudoelastic force-deflection curves for 30 NiTi coil springs (used intra-orally) and 15 matched laboratory control springs (simulated intra-oral conditions - artificial saliva, 37°C) were tested pre- and post-retrieval via Dynamic Mechanical Analysis (DMA) and the Instron machine, respectively, to evaluate amount of force loss and hysteresis change following 4, 8, or 12 weeks of working time (n=10 per group). Effect of the oral environment and clinical use on force properties were evaluated by comparing in vivo and in vitro data. Results The springs studied showed a statistically significant decrease in force (~12%) following 4 weeks of clinical use (p<0.01), with a further significant decrease (~7%) from 4–8 weeks (p=0.03) and force levels appearing to remain steady thereafter. Clinical space closure at an average rate of 0.91mm per month was still observed despite this decrease in force. In vivo and in vitro force loss data were not statistically different. Conclusions NiTi closed coil springs do not deliver constant forces when used intra-orally, but they still allow for space closure rates of ~1mm/month.

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Section: Discussionmentioning

confidence: 89%

“…5, 13–17 Maganzini et al examined 14 different types of NiTi closed coil springs in vitro from five different companies and concluded that most of the springs tested did not exhibit constant deactivation forces or physiologic peak load forces. 5 …”

Section: Introductionmentioning

confidence: 99%

In-vivo force decay of nickel-titanium closed-coil springs

Cox¹,

Nguyen²,

Koroluk³

et al. 2014

American Journal of Orthodontics and Dentofacial Orthopedics

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“…Therefore, loads were decreased 10% per week and applied at the centre of the tooth crown in simulation of both tipping and bodily movements, following the methods of Burstone [25] and Angolkar et al [26].…”

Section: Simulation Of Tooth Movement Processesmentioning

confidence: 99%

Three-dimensional FEM analysis of stress distribution in dynamic maxillary canine movement

Jing

Han

Cheng³

et al. 2013

Chin. Sci. Bull.

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An alteration in stress/strain distribution within periodontal ligament (PDL) occurs when the tooth is mechanical stimulated in orthodontic treatment. The majority of previous finite element studies were confined to a static evaluation on initial loading status, and a dynamic long-term analysis was rarely performed in orthodontics. The present study sought to analyze the stress distribution patterns within tooth root, PDL, and alveolar bone during dynamic canine tipping and bodily movement with three-dimensional finite element method in four consecutive therapeutic weeks. We observed that the highest stress was on root surface, secondly alveolar bone, and finally, PDL for either tipping or bodily movement. Throughout the PDL and root surface, the highest stress was always around the cervical area in both patterns of movement through four phases. Moreover, a lower and more uniform stress distribution was produced during bodily movement compared with tipping movement. These results indicated that canine translation might be healthier for periodontal tissue than tipping movement; the cervical region bore a greater load and might also be a susceptible area for tissue damage (except for the apex) regardless of movement pattern. dynamic tooth movement, finite element method (FEM), stress distribution Citation:Jing Y, Han X L, Cheng B H, et al. Three-dimensional FEM analysis of stress distribution in dynamic maxillary canine movement.

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“…10 However, it is difficult to obtain this information from some suppliers. Clinicians should not assume that all nickel titanium wires or springs perform in the same way.…”

Section: Introductionmentioning

confidence: 99%

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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Force degradation of closed coil springs: An in vitro evaluation

Cited by 46 publications

References 19 publications

In-vivo force decay of nickel-titanium closed-coil springs

In-vivo force decay of nickel-titanium closed-coil springs

Three-dimensional FEM analysis of stress distribution in dynamic maxillary canine movement

Forces of Various Nickel Titanium Closed Coil Springs

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