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

American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics (2014-04-08)
Crystal Cox, Tung Nguyen, Lorne Koroluk, Ching-Chang Ko
RESUMEN

Nickel-titanium 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 was to evaluate changes in force-decay properties of nickel-titanium closed-coil springs after clinical use. Pseudoelastic force-deflection curves for 30 nickel-titanium coil springs (used intraorally) and 15 matched laboratory control springs (simulated intraoral conditions: artificial saliva, 37°C) were tested before and after retrieval via dynamic mechanical analysis and a testing machine, respectively, to evaluate the amounts of force-loss and hysteresis change after 4, 8, or 12 weeks of working time (n = 10 per group). The effects of the oral environment and clinical use on force properties were evaluated by comparing in-vivo and in-vitro data. The springs studied showed a statistically significant decrease in force (approximately 12%) after 4 weeks of clinical use (P <0.01), with a further significant decrease (approximately 7%) from 4 to 8 weeks (P = 0.03), and force levels appearing to remain steady thereafter. Clinical space closure at an average rate of 0.91 mm per month was still observed despite this decrease in force. In-vivo and in-vitro force-loss data were not statistically different. Nickel-titanium closed-coil springs do not deliver constant forces when used intraorally, but they still allow for space-closure rates of approximately 1 mm per month.

MATERIALES
Referencia del producto
Marca
Descripción del producto

Sigma-Aldrich
Raney®-Nickel, W.R. Grace and Co. Raney® 2800, slurry, in H2O, active catalyst
Sigma-Aldrich
Nickel, powder, <50 μm, 99.7% trace metals basis
Sigma-Aldrich
Nickel, nanopowder, <100 nm avg. part. size, ≥99% trace metals basis
Sigma-Aldrich
Nickel, powder, <150 μm, 99.99% trace metals basis
Sigma-Aldrich
Nickel, foil, thickness 0.125 mm, ≥99.9%
Nickel, foam, 150x150mm, thickness 1.6mm, bulk density 0.45g/cm3, porosity 95%, 95%
Sigma-Aldrich
Raney®-Nickel, W.R. Grace and Co. Raney® 4200, slurry, in H2O, active catalyst
Sigma-Aldrich
Nickel, powder, <1 μm, 99.8% trace metals basis
Sigma-Aldrich
Nickel, foil, thickness 0.5 mm, 99.98% trace metals basis
Sigma-Aldrich
Raney®-Nickel, W.R. Grace and Co. Raney® 2400, slurry, in H2O, active catalyst
Sigma-Aldrich
Nickel, wire, diam. 0.5 mm, ≥99.9% trace metals basis
Sigma-Aldrich
Nickel, foil, thickness 0.1 mm, 99.98% trace metals basis
Sigma-Aldrich
Nickel, wire, diam. 0.25 mm, ≥99.9%
Sigma-Aldrich
Nickel, rod, diam. 6.35 mm, ≥99.99% trace metals basis
Sigma-Aldrich
Raney®-Nickel, W.R. Grace and Co. Raney® 3202, slurry, in H2O, active catalyst
Sigma-Aldrich
Nickel, wire, diam. 0.5 mm, ≥99.99% trace metals basis
Nickel, tube, 500mm, outside diameter 1.8mm, inside diameter 1.6mm, wall thickness 0.1mm, hard, 99.5%
Nickel, wire reel, 20m, diameter 0.025mm, as drawn, 99.98%
Nickel, wire reel, 1m, diameter 1.0mm, as drawn, 99%
Nickel, mesh, 100x250mm, nominal aperture 0.73mm, wire diameter 0.25mm, 26x26 wires/inch, open area 55%, plain weave mesh, 99%
Nickel, sphere, 100pcs, diameter 1.0mm, precision sphere grade 200, 99%
Nickel, foil, 50x50mm, thickness 0.30mm, as rolled, 99.98%
Nickel, wire reel, 5m, diameter 1.0mm, hard, 99.98%
Nickel, wire reel, 1m, diameter 0.75mm, as drawn, 99%
Nickel, rod, 100mm, diameter 12.7mm, 99.98%
Nickel, sphere, 200pcs, diameter 3.0mm, precision sphere grade 200, 99%
Nickel, foil, light tested, 100x100mm, thickness 0.015mm, 99.9%
Nickel, foil, 10mm disks, thickness 0.15mm, annealed, 99%
Nickel, foil, 4mm disks, thickness 0.075mm, annealed, 99%
Nickel, foil, 4mm disks, thickness 0.075mm, as rolled, 99.98%

Redes sociales

LinkedIn icon
Twitter icon
Facebook Icon
Instagram Icon

Merck

Investigación. Desarrollo. Producción.

Somos un proveedor líder para la industria de Ciencias de la Vida con soluciones y servicios para investigación, desarrollo y producción biotecnológicos, y para desarrollo y producción de tratamientos farmacéuticos

© 2021 Merck KGaA, Darmstadt, Alemania y/o sus filiales. Todos los derechos reservados.

Queda estrictamente prohibida la reproducción sin permiso de cualquiera de los materiales de la página web.