title: Comparison of the Load-Deflection Characteristics of Aesthetic and Conventional Super Elastic Ni-Ti Orthodontic Arch Wires in Conventional and Metal-Insert Ceramic Brackets.
abstract: BACKGROUND
  Coated arch wires and ceramic brackets have been introduced to improve aesthetics during orthodontic treatment.
  
  
  OBJECTIVE
  The aim of this study was to determine the effects of coating on the physical properties of aesthetic orthodontic wires.
  
  
  METHODS
  Five round wires (0.016 inch) were obtained from each of three brands: conventional uncoated super elastic Nickel Titanium (Ni-Ti) (Rematitian Lite; Dentaurum, Ispringen, Germany), HUBIT (Teflon Coated, Korea), G&H (Epoxy Coated, Greenwood, Indiana, USA) which belonged to maxillary arch. Two types of standard ceramic brackets (conventional and metal-insert type, Ortho Technology, Tampa, Florida, USA) with the slot size of 0.022×0.028 inches were used. A simulation device was fabricated to resemble a model of human dental arch and each of the specimen was tested in three-point bending test. The test was conducted in the buccolingual plane with crosshead speed of 1mm/minute pressure from metal pole. Each sample was loaded until a deflection of 3.0 mm was produced. The mean values of maximum loading force, unloading force and clinical plateau length were recorded. One-way ANOVA and Tukey tests were used at p<0.05.
  
  
  RESULTS
  Uncoated Ni-Ti arch wire showed higher mean values of maximum loading and unloading force than that of coated aesthetic wires similar to ceramic brackets while G&H wire and metal-insert ceramic brackets presented the lowest values. The longest clinical plateau length was observed in G&H wires and metal-insert ceramic bracket.
  
  
  CONCLUSIONS
  The coating processes for HUBIT (Teflon Coated, Korea), G&H (Epoxy Coated, Greenwood, Indiana, USA) wires might influence bending behaviour which can cause decrease in loading and unloading force.
authors.affiliation: Associate Professor, Department of Orthodontics, Shahid Sadoughi University of Medical Sciences , Yazd, Iran .
authors.forename: Hosseinagha
authors.initials: H
authors.lastname: Aghili
authors.affiliation: Professor, Department of Orthodontics, Shahid Sadoughi University of Medical Sciences , Yazd, Iran .
authors.forename: Soghra
authors.initials: S
authors.lastname: Yassaei
authors.affiliation: Assistant Professor, Department of Orthodontics, Shahid Sadoughi University of Medical Sciences , Yazd, Iran .
authors.forename: Neda
authors.initials: N
authors.lastname: Joshan
authors.affiliation: Orthodontics Resident, Department of Orthodontics, Shahid Sadoughi University of Medical Sciences , Yazd, Iran .
authors.forename: Nemat
authors.initials: N
authors.lastname: Hoseini
keywords: Coated wire; Mechanical properties; Superelasticity; Three-point bending