title: Force-deflection properties of superelastic nickel-titanium archwires.
abstract: This in vitro study compared the force-deflection behavior of 8 superelastic nickel-titanium orthodontic wires (0.017 x 0.025 in) under controlled moment and temperature. To simulate leveling a lateral incisor, brackets and first molar tubes without tip and angulation were used. The wires (n = 5) were ligated into stainless steel brackets attached to a plastic jig to simulate a mandibular arch. A testing machine (Instron) applied deflections of 0.2 to 2.0 mm at 35 degrees C in the lateral incisor area. Force-deflection diagrams were determined from the passive position to an activation of 2 mm and then during deactivation. Forces on deactivation at a deflection of 1 mm were compared by analysis of variance. Significant differences (P < .05) in forces were observed among wires. All wires exhibited superelastic behavior, but in stratified loading levels.
authors.affiliation: Department of Orthodontics, Faculty of Dentistry Sciences, University of Marília, Bauru, Brazil.
authors.forename: J A
authors.initials: JA
authors.lastname: Gurgel
authors.forename: S
authors.initials: S
authors.lastname: Kerr
authors.forename: J M
authors.initials: JM
authors.lastname: Powers
authors.forename: V
authors.initials: V
authors.lastname: LeCrone
mesh_terms: D000704:Analysis of Variance; D003722:Dental Alloys; D003799:Dental Stress Analysis; D004548:Elasticity; D008422:Materials Testing; D003765:Models, Dental; D009532:Nickel; D009969:Orthodontic Wires; D014025:Titanium
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; C093824:Martensite; D009532:Nickel; D014025:Titanium