title: Comparative study of friction between metallic and conventional interactive self-ligating brackets in different alignment conditions.
abstract: OBJECTIVE
  The aim of this study was to compare the friction between three bracket models: conventional stainless steel (Ovation, Dentsply GAC), self-ligating ceramic (In-Ovation, Denstply GAC) and self-ligating stainless steel brackets (In-Ovation R, Dentsply GAC).
  
  
  METHODS
  Five brackets were used for each model. They were bonded to an aluminum prototype that allowed the simulation of four misalignment situations (n = 10). Three of these situations occured at the initial phase (in which a 0.016-in nickel-titanium wire was used): 1. horizontal; 2. vertical; and 3. simultaneous horizontal/vertical. One of the situations occurred at the final treatment phase: 4. no misalignment (in which a 0.019 x 0.025-inch stainless steel rectangular wire was used). The wires slipped through the brackets and friction was measured by a Universal Testing Machine.
  
  
  RESULTS
  Analysis of variance followed by Tukey's Test for multiple comparisons (α = 0.05) were applied to assess the results. Significant interaction (p < 0.01) among groups was found. For the tests that simulated initial alignment, Ovation® bracket produced the highest friction. The two self-ligating models resulted in lower and similar values, except for the horizontal situation, in which In-Ovation C® showed lower friction, which was similar to the In-Ovation R® metallic model. For the no misalignment situation, the same results were observed.
  
  
  CONCLUSIONS
  The self-ligating system was superior to the conventional one due to producing less friction. With regard to the material used for manufacturing the brackets, the In-Ovation C® ceramic model showed less friction than the metallic ones.
authors.forename: Sérgio Ricardo
authors.initials: SR
authors.lastname: Jakob
authors.forename: Davison
authors.initials: D
authors.lastname: Matheus
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Jimenez-Pellegrin
authors.forename: Cecília Pedroso
authors.initials: CP
authors.lastname: Turssi
authors.forename: Flávia Lucisano Botelho
authors.initials: FL
authors.lastname: Amaral
mesh_terms: D002516:Ceramics / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry; D003799:Dental Stress Analysis / Q000295:instrumentation; D017276:Friction; D006801:Humans; D008422:Materials Testing; D009532:Nickel / Q000737:chemistry; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D019279:Resin Cements / Q000737:chemistry; D012399:Rotation; D013193:Stainless Steel / Q000737:chemistry; D013314:Stress, Mechanical; D014025:Titanium / Q000737:chemistry; D019415:Torque
chemical_list: D003722:Dental Alloys; D003764:Dental Materials; D019279:Resin Cements; C477790:Transbond XT; C040654:titanium nickelide; D013193:Stainless Steel; D009532:Nickel; D014025:Titanium
keywords: Esthetics; Friction; Orthodontic brackets