title: [Color changes induced by fluoride on nickel-titanium orthodontic wires].
abstract: OBJECTIVE
  To observe the color changes of nickel-titanium (Ni-Ti) orthodontic wires induced by fluoride.
  
  
  METHODS
  Each 40 samples of 4 kinds of nickel-titanium orthodontic wires (IMD, SL, TP, YY) were put into artificial saliva with sodium fluoride at different F concentrations (0.05%, 0.10%, 0.15%) and artificial saliva, separately. Dislodged the species and immersed them into artificial saliva with sodium fluoride for 3 minutes, then washed them with deionized water, and put back to artificial saliva, this course should be repeated 3 times per day. The whole immersion test lasted for 28 days. The color and micro-morphous changing were observed.
  
  
  RESULTS
  The color changes came to be more serious as the F- concentration growing (P < 0.05). At the same F- concentration, the color changes of IMD and YY were higher than SL and YP (P < 0.01), while there were no significant difference between IMD and YY, SL and TP (P > 0.05).
  
  
  CONCLUSIONS
  Fluoride can change the color of Ni-Ti wire. Different Ni-Ti wires get different changes at the same F- concentration.
authors.affiliation: Dept. of Stomatology, The Affiliated Hospital of Hangzhou Normal University, Hangzhou 310015, China.
authors.forename: Chang-Bai
authors.initials: CB
authors.lastname: Ma
authors.forename: Xin-Qiang
authors.initials: XQ
authors.lastname: Liu
authors.forename: Jin-Hua
authors.initials: JH
authors.lastname: Li
mesh_terms: D003722:Dental Alloys; D005459:Fluorides; D009532:Nickel; D009969:Orthodontic Wires; D010710:Phosphates; D012464:Saliva, Artificial; D012969:Sodium Fluoride; D014025:Titanium
chemical_list: D003722:Dental Alloys; D010710:Phosphates; D012464:Saliva, Artificial; C040654:titanium nickelide; C012980:fluorophosphate; D009532:Nickel; D012969:Sodium Fluoride; D014025:Titanium; D005459:Fluorides