title: Friction between various self-ligating brackets and archwire couples during sliding mechanics.
abstract: BACKGROUND
  The aim of this study was to evaluate the frictional resistance between active and passive self-ligating brackets and 0.019 × 0.025-in stainless steel archwire during sliding mechanics by using an orthodontic sliding simulation device.
  
  
  METHODS
  Maxillary right first premolar active self-ligating brackets In-Ovation R, In-Ovation C (both, GAC International, Bohemia, NY), and SPEED (Strite Industries, Cambridge, Ontario, Canada), and passive self-ligating brackets SmartClip (3M Unitek, Monrovia, Calif), Synergy R (Rocky Mountain Orthodontics, Denver, Colo), and Damon 3mx (Ormco, Orange, Calif) with 0.022-in slots were used. Frictional force was measured by using an orthodontic sliding simulation device attached to a universal testing machine. Each bracket-archwire combination was tested 30 times at 0° angulation relative to the sliding direction. Statistical comparisons were performed with 1-way analysis of variance (ANOVA) followed by Dunn multiple comparisons. The level of statistical significance was set at P <0.05.
  
  
  RESULTS
  The Damon 3mx brackets had significantly the lowest mean static frictional force (8.6 g). The highest mean static frictional force was shown by the SPEED brackets (83.1 g). The other brackets were ranked as follows, from highest to lowest, In-Ovation R, In-Ovation C, SmartClip, and Synergy R. The mean static frictional forces were all statistically different. The ranking of the kinetic frictional forces of bracket-archwire combinations was the same as that for static frictional forces. All bracket-archwire combinations showed significantly different kinetic frictional forces except SmartClip and In-Ovation C, which were not significantly different from each other.
  
  
  CONCLUSIONS
  Passive self-ligating brackets have lower static and kinetic frictional resistance than do active self-ligating brackets with 0.019 × 0.025-in stainless steel wire.
authors.affiliation: Postgraduate student, Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pa.
authors.forename: Sennay
authors.initials: S
authors.lastname: Stefanos
authors.affiliation: Assistant professor, Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pa. Electronic address: antonino@dental.upenn.edu.
authors.forename: Antonino G
authors.initials: AG
authors.lastname: Secchi
authors.affiliation: Clinical assistant professor, Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pa.
authors.forename: Guy
authors.initials: G
authors.lastname: Coby
authors.affiliation: Postgraduate student, Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pa.
authors.forename: Nipul
authors.initials: N
authors.lastname: Tanna
authors.affiliation: Associate professor, Department of Restorative and Preventive Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pa.
authors.forename: Francis K
authors.initials: FK
authors.lastname: Mante
mesh_terms: D000704:Analysis of Variance; D003799:Dental Stress Analysis; D017276:Friction; D008422:Materials Testing; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D013193:Stainless Steel
chemical_list: D013193:Stainless Steel