title: Archwire vibration and stick-slip behavior at the bracket-archwire interface.
abstract: BACKGROUND
  It is unknown whether or not intraoral vibrations affect stick-slip behavior at orthodontic bracket-archwire interfaces. In this study, we evaluated bracket-archwire stick-slip behavior as a function of ligation method and archwire vibration.
  
  
  METHODS
  In-vivo archwire vibrations were measured to obtain frequencies and amplitudes for ex-vivo testing. A piezoresistive accelerometer ligated to the maxillary right canines of 6 subjects transduced the intraoral vibrations. All subjects gave informed consent to participate. Amplitude and frequency of the vibrations were quantified and used in a bench-top friction testing apparatus. Active and passive ligation methods were compared for 9 vibration scenarios. The amount of time to move the bracket along a stainless steel wire was recorded in 90 trials. Analysis of variance and post-hoc tests were used for statistical analyses of the data.
  
  
  RESULTS
  During carrot biting, orthodontic wire vibrations had a mean frequency of 98 Hz and a peak-to-peak mean amplitude of 151 mV. The bench-top stick-slip measurement trials containing medium (150 mV) and high (190 mV) amplitude vibrations had significantly less friction (ln, s), 4.81 ± 2.08 and 4.67 ± 2.00, respectively, than those subjected to low (110 mV) amplitudes, 5.80 ± 1.39 (P = 0.04). There were no significant differences between passive and active ligation methods.
  
  
  CONCLUSIONS
  Amplitudes of archwire vibrations affect stick-slip behavior at the bracket-archwire interfaces.
authors.affiliation: School of Dentistry, University of Missouri-Kansas City, USA.
authors.forename: Julie E
authors.initials: JE
authors.lastname: Olson
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Nickel
authors.forename: Mary P
authors.initials: MP
authors.lastname: Walker
authors.forename: Laura R
authors.initials: LR
authors.lastname: Iwasaki
mesh_terms: D003722:Dental Alloys; D003799:Dental Stress Analysis / Q000295:instrumentation; D017276:Friction; D006801:Humans; D015233:Models, Statistical; D009532:Nickel; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D013193:Stainless Steel; D014025:Titanium; D014732:Vibration
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D013193:Stainless Steel; D009532:Nickel; D014025:Titanium