title: In vitro biocompatibility of nickel-titanium esthetic orthodontic archwires.
abstract: OBJECTIVE
  To investigate the cytotoxicity of nickel-titanium (NiTi) esthetic orthodontic archwires with different surface coatings.
  
  
  METHODS
  Three fully coated, tooth-colored NiTi wires (BioCosmetic, Titanol Cosmetic, EverWhite), two ion-implanted wires (TMA Purple, Sentalloy High Aesthetic), five uncoated NiTi wires (BioStarter, BioTorque, Titanol Superelastic, Memory Wire Superelastic, and Sentalloy), one β-titanium wire (TMA), and one stainless steel wire (Stainless Steel) were considered for this study. The wire samples were placed at 37°C in airtight test tubes containing Dulbecco's Modified Eagle's Medium (0.1 mg/mL) for 1, 7, 14, and 30 days. The cell viability of human gingival fibroblasts (HGFs) cultured with this medium was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Data were analyzed by a two-way analysis of variance (α  =  .05).
  
  
  RESULTS
  The highest cytotoxic effect was reached on day 30 for all samples. The archwires exhibited a cytotoxicity on HGFs ranging from "none" to "slight," with the exception of the BioTorque, which resulted in moderate cytotoxicity on day 30. Significant differences were found between esthetic archwires and their uncoated pairs only for BioCosmetic (P  =  .001) and EverWhite (P < .001).
  
  
  CONCLUSIONS
  Under the experimental conditions, all of the NiTi esthetic archwires resulted in slight cytotoxicity, as did the respective uncoated wires. For this reason their clinical use may be considered to have similar risks to the uncoated archwires.
authors.affiliation: a  Research Fellow, School of Orthodontics, Department of Neurosciences, Reproductive Sciences and Oral Sciences, University of Naples "Federico II," Naples, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Rongo
authors.affiliation: b  Associate Professor, School of Orthodontics, Department of Neurosciences, Reproductive Sciences and Oral Sciences, University of Naples "Federico II," Naples, Italy.
authors.forename: Rosa
authors.initials: R
authors.lastname: Valletta
authors.affiliation: a  Research Fellow, School of Orthodontics, Department of Neurosciences, Reproductive Sciences and Oral Sciences, University of Naples "Federico II," Naples, Italy.
authors.forename: Rosaria
authors.initials: R
authors.lastname: Bucci
authors.affiliation: c  PhD, Department of Neurosciences, Reproductive Sciences and Oral Sciences, University of Naples "Federico II," Naples, Italy.
authors.forename: Virginia
authors.initials: V
authors.lastname: Rivieccio
authors.affiliation: d  Director of Division of Dentistry, Department of Pediatric Surgery, Bambino Gesù Children's Hospital, Rome, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Galeotti
authors.affiliation: e  Professor and Chair, School of Orthodontics, Department of Neurosciences, Reproductive Sciences and Oral Sciences, University of Naples "Federico II," Naples, Italy.
authors.forename: Ambrosina
authors.initials: A
authors.lastname: Michelotti
authors.affiliation: f  Research Fellow, School of Orthodontics, Department of Neurosciences, Reproductive Sciences and Oral Sciences, University of Naples "Federico II," Naples, Italy; and Division of Dentistry, Department of Pediatric Surgery, Bambino Gesù Children's Hospital, Rome, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: D'Antò
mesh_terms: D003722:Dental Alloys; D004955:Esthetics, Dental; D006801:Humans; D008422:Materials Testing; D009532:Nickel; D009969:Orthodontic Wires; D013193:Stainless Steel; D013499:Surface Properties; D014025:Titanium
chemical_list: D003722:Dental Alloys; D013193:Stainless Steel; D009532:Nickel; D014025:Titanium
keywords: Biocompatibility; Coated wires; Esthetic archwires; Orthodontics