title: Contemporary esthetic nickel-titanium wires: do they deliver the same forces?
abstract: OBJECTIVE
  To test for differences in loading and unloading forces delivered by six coated nickel-titanium wires and their noncoated equivalents.
  
  
  METHODS
  From six commercial companies, 0.016-inch diameter round and 0.016 × 0.022-inch rectangular cross-section nickel-titanium wires were procured "as is": Rocky Mountain Orthodontics (Denver, Colo), TP Orthodontics (La Porte, Ind), American Orthodontics (AO; Sheboygan, Wis), G&H (Franklin, Ind), Opal Orthodontics (South Jordan, Utah), and Forestadent USA (St Louis, Mo) (round only). The wires were evaluated using a three-point bending test based on the method in ISO Standard 15841.
  
  
  RESULTS
  No statistically significant differences (P > .05) in force values were found between coated and noncoated wires, listed by deflection in three-point bending, for these specific groups: 1 mm, TP round; 2 mm, TP round and G&H rectangular; 3 mm, G&H round and G&H rectangular; 2.5 mm,TP round and G&H rectangular; 1.5 mm, TP round, G&H round, G&H rectangular, and AO rectangular; and 0.5 mm, AO rectangular and G&H round.
  
  
  CONCLUSIONS
  Some manufacturers market esthetic wires delivering forces similar to the equivalent noncoated wires, when tested according to a standard three-point bend method.
authors.affiliation: a  Private practice, New York, NY.
authors.forename: Bradford
authors.initials: B
authors.lastname: Washington
authors.forename: Carla A
authors.initials: CA
authors.lastname: Evans
authors.forename: Grace
authors.initials: G
authors.lastname: Viana
authors.forename: Ana
authors.initials: A
authors.lastname: Bedran-Russo
authors.forename: Spiro
authors.initials: S
authors.lastname: Megremis
mesh_terms: D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003722:Dental Alloys / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D004955:Esthetics, Dental; D006801:Humans; D008422:Materials Testing; D009532:Nickel / Q000737:chemistry*; D009969:Orthodontic Wires; D018583:Pliability; D013314:Stress, Mechanical; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium
keywords: Nickel-titanium archwires; Orthodontics