Color stability and fluorescence of different orthodontic esthetic archwires

Objective:To evaluate the color stability of six esthetic archwires at different time periods and their fluorescence.Materials and 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.