title: Estimation of changes in nickel and chromium content in nickel-titanium and stainless steel orthodontic wires used during orthodontic treatment: An analytical and scanning electron microscopic study.
abstract: BACKGROUND
  The biocompatibility of orthodontic dental alloys has been investigated over the past 20 years, but the results have been inconclusive. The study compares standard 3 M Unitek nickel-titanium (NiTi) and stainless steel archwires with locally available JJ orthodontics wires. Scanning electron microscope (SEM) study of surface changes and complexometric titration to study compositional change was performed.
  
  
  METHODS
  Ten archwires each of group 1-3 M 0.016" NiTi, group 2-JJ 0.016" NiTi, group 3-3 M 0.019" *0.025" SS and group 4-JJ SS contributed a 10 mm piece of wire for analysis prior to insertion in the patient and 6 weeks post insertion. SEM images were recorded at ×2000, ×4000 and ×6000 magnification. The same samples were subjected to complexiometric titration using ethylenediaminetetraacetic acid to gauge the actual change in the composition.
  
  
  RESULTS
  The SEM images of all the archwires showed marked changes with deep scratches and grooves and dark pitting corrosion areas post intraoral use. 3M wires showed an uniform criss-cross pattern in as received wires indicating a coating which was absent after intraoral use. There was a significant release of Nickel and Chromium from both group 3 and 4. Group 2 wires released ions significantly more than group 1 (P = 0.0).
  
  
  CONCLUSIONS
  Extensive and stringent trials are required before certifying any product to be used in Orthodontics.
authors: Department of Orthodontics, Government Dental College and Hospital, Jaipur, Rajasthan, India.
authors: Vandana
authors: V
authors: Kararia
authors: Department of Orthodontics, Government Dental College and Hospital, Jaipur, Rajasthan, India.
authors: Pradeep
authors: P
authors: Jain
authors: Department of Orthodontics, Government Dental College and Hospital, Jaipur, Rajasthan, India.
authors: Seema
authors: S
authors: Chaudhary
authors: Department of Conservative Dentistry and Endodontics, Rajasthan Dental College and Hospital, Jaipur, Rajasthan, India.
authors: Nitin
authors: N
authors: Kararia
keywords: Biocompatibility; complexometric titration; nickel titanium; stainless steel