title: Color stability and fluorescence of different orthodontic esthetic archwires.
abstract: OBJECTIVE
  To evaluate the color stability of six esthetic archwires at different time periods and their fluorescence.
  
  
  METHODS
  Samples were evaluated after 7, 14, and 21 days of immersion in staining solution. Color measurements were performed by means of a spectrophotometer according to the Commission Internationale de I'Eclairage L*a*b* system, and color changes (ΔE*) and National Bureau of Standards units were computed. The fluorescence of as-received samples was evaluated by two observers and compared with that of a bovine central incisor. Statistical differences were investigated using analysis of variance and Tukey's post hoc test.
  
  
  RESULTS
  All brands showed statistically significant color change after 21 days (ΔE* from 1.88 to 12.06). The Optis archwire (fiber-reinforced composite) presented the highest color alteration, although staining was observed only near its ends. The Trianeiro archwire (coated nickel-titanium) and the Ortho Organizers archwire (coated stainless steel) presented with less color change. The Optis archwire was the only one that presented with fluorescence similar to that of bovine teeth.
  
  
  CONCLUSIONS
  All esthetic archwires assessed showed clinically noticeable color change after 21 days in staining solution. The optical properties of currently available esthetic archwires may not yet be ideal.
authors.affiliation: Department of Orthodontics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Dayanne Lopes
authors.initials: DL
authors.lastname: da Silva
authors.forename: Claudia Trindade
authors.initials: CT
authors.lastname: Mattos
authors.forename: Marcus Vinicius Almeida
authors.initials: MV
authors.lastname: de Araújo
authors.forename: Antônio Carlos
authors.initials: AC
authors.lastname: de Oliveira Ruellas
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002417:Cattle; D003116:Color / Q000592:standards*; D003188:Composite Resins / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry; D005453:Fluorescence; D008422:Materials Testing; D016382:Orthodontic Appliance Design; D009969:Orthodontic Wires; D013053:Spectrophotometry; D013193:Stainless Steel / Q000737:chemistry; D013499:Surface Properties
chemical_list: D003188:Composite Resins; D003722:Dental Alloys; D013193:Stainless Steel