Force characteristics of nickel-titanium open-coil springs.
Am J Orthod Dentofacial Orthop
; 138(2): 142.e1-7; discussion 142-3, 2010 Aug.
Article
em En
| MEDLINE
| ID: mdl-20691352
ABSTRACT
INTRODUCTION:
The objective of this study was to quantify the properties of commercially available nickel-titanium open-coil springs.METHODS:
Eleven springs from 3 manufacturers were tested 5 times over a 12-week period. A universal testing machine was used to measure the force generated when open-coil springs were compressed to half of their original length and then gradually allowed to decompress.RESULTS:
The average forces generated at the initial recording session for uniformly wound springs from GAC International (Bohemia, NY) and 3M Unitek (Monrovia, Calif) were 19.3% to 42.7% and 9.7% to 38.8% below the manufacturers' labeled force levels, respectively. GAC's 100-, 150-, and 200-g stop-wound coils demonstrated statistically and clinically significant stepwise force degradation over the 12-week experimental period (P <0.0001). GAC's uniformly wound light (100 g) coils generated the lowest load-deflection ratios (23.7 g/mm).CONCLUSIONS:
Open coils might need to be compressed by more than one-third of their original length to produce the labeled forces. Uniformly wound coils generally produce lower load-deflection ratios and maximum forces, which are generally more acceptable for tooth movement.
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Base de dados:
MEDLINE
Assunto principal:
Aparelhos Ortodônticos
/
Técnicas de Movimentação Dentária
/
Desenho de Aparelho Ortodôntico
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Ligas Dentárias
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article