title: In-vitro assessment of oxidative stress generated by orthodontic archwires.
abstract: BACKGROUND
  Several metals undergo redox cycling, producing free radicals and generating oxidative stress. The purpose of this study was to investigate in-vitro oxidative stress of orthodontic archwires made of various alloys.
  
  
  METHODS
  Mouse fibroblast cells L929 were exposed to 6 types of archwires, and the concentration of the oxidative stress marker 8-hydroxy-2'-deoxyguanosine in DNA was evaluated. Trypan blue dye was used in the determination of cell viability and numbers.
  
  
  RESULTS
  Standard nickel-titanium archwires generated the highest oxidative stress, significantly higher than all other wires and the controls (P <0.05), and coated nickel-titanium, copper-nickel-titanium, and cobalt-chromium were lower than nickel-titanium (P <0.05), but higher than titanium-molybdenum and the negative and absolute controls (P <0.05). Titanium-molybdenum and stainless steel generated the lowest stress. Nickel-titanium induced the lowest viability, lower than the negative and absolute controls and all other wires (P <0.05) except titanium-molybdenum. Stainless steel showed the highest viability. Nickel-titanium produced the highest inhibition of cell growth, higher than all samples (P <0.05) except the positive control and cobalt-chromium. The lowest inhibition was observed in stainless steel and titanium-molybdenum, lower than nickel-titanium, cobalt-chromium, and the positive control (P <0.05).
  
  
  CONCLUSIONS
  All orthodontic archwires generate oxidative stress in vitro. Stainless steel archwires have the highest and nickel-titanium the lowest biocompatibility.
authors.affiliation: Department of Pediatric Dentistry and Orthodontics, School of Medicine, University of Rijeka, Croatia. spaljs@medri.hr
authors.forename: Stjepan
authors.initials: S
authors.lastname: Spalj
authors.forename: Magda
authors.initials: M
authors.lastname: Mlacovic Zrinski
authors.forename: Vedrana
authors.initials: V
authors.lastname: Tudor Spalj
authors.forename: Zorana
authors.initials: Z
authors.lastname: Ivankovic Buljan
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000497:Alloys / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D002478:Cells, Cultured; D002858:Chromium Alloys / Q000494:pharmacology; D003300:Copper / Q000494:pharmacology; D004249:DNA Damage / Q000187:drug effects*; D003722:Dental Alloys / Q000494:pharmacology*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D009532:Nickel / Q000494:pharmacology; D009969:Orthodontic Wires; D018384:Oxidative Stress / Q000187:drug effects*; D012238:Rhodium / Q000494:pharmacology; D012464:Saliva, Artificial / Q000494:pharmacology; D013193:Stainless Steel / Q000494:pharmacology; D014025:Titanium / Q000494:pharmacology
chemical_list: D000497:Alloys; D002858:Chromium Alloys; C415948:Copper NiTi; D003722:Dental Alloys; D012464:Saliva, Artificial; C525450:titanium molybdenum alloy; C040654:titanium nickelide; D013193:Stainless Steel; D003300:Copper; D009532:Nickel; D000080242:8-Hydroxy-2'-Deoxyguanosine; D014025:Titanium; D012238:Rhodium; D003849:Deoxyguanosine