title: Resistance to Sliding in Clear and Metallic Damon 3 and Conventional Edgewise Brackets: an In vitro Study.
abstract: BACKGROUND
  Frictional forces are considered as important counterforce to orthodontic tooth movement. It is claimed that self-ligating brackets reduce the frictional forces.
  
  
  OBJECTIVE
  The aim of this study was to compare the resistance to sliding in metallic and clear Damon brackets with the conventional brackets in a wet condition.
  
  
  METHODS
  The samples included 4 types of brackets; metallic and clear Damon brackets and metallic and clear conventional brackets (10 brackets in each group). In this study, stainless steel wires sized 0.019×0.025 were employed and the operator's saliva was used to simulate the conditions of oral cavity. The tidy-modified design was used for simulation of sliding movement. The resistance to sliding and static frictional forces was measured by employing Testometric machine and load cell.
  
  
  RESULTS
  The mean (±SD) of resistance to sliding was 194.88 (±26.65) and 226.62 (±39.9) g in the esthetic and metallic Damon brackets, while these values were 187.81(±27.84) and 191.17(±66.68) g for the clear and metallic conventional brackets, respectively. Static frictional forces were 206.4(±42.45) and 210.38(±15.89) g in the esthetic and metallic Damon brackets and 220.63(±49.29) and 215.13(±62.38) g in the clear and metallic conventional brackets. According to two-way ANOVA, no significant difference was observed between the two bracket materials (clear and metal) and the two types of bracket (self-ligating versus conventional) regarding resistance to sliding (p= 0.17 and p= 0.23, respectively) and static frictional forces (p= 0.55 and p= 0.96, respectively).
  
  
  CONCLUSIONS
  Neither the type of bracket materials nor their type of ligation made difference in resistance to sliding and static friction.
authors.affiliation: Dept. of Orthodontics, School of Dentistry, Hamadan University of Medical Sciences, Hamedan, Iran;
authors.forename: Mohammad
authors.initials: M
authors.lastname: Karim Soltani
authors.affiliation: Dept. of Mechanical Engineering, School of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran;
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Golfeshan
authors.affiliation: Dept. of Mechanical Engineering, School of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran;
authors.forename: Yoones
authors.initials: Y
authors.lastname: Alizadeh
authors.affiliation: Dept. of Orthodontics, School of Dentistry, Hamadan University of Medical Sciences, Hamedan, Iran;
authors.forename: Jabraiel
authors.initials: J
authors.lastname: Mehrzad
keywords: Friction; Self-ligating Brackets; Sliding Technique