title: Influence of ligation method on friction resistance of lingual brackets with different second-order angulations: an in vitro study.
abstract: OBJECTIVE
  To evaluate stainless steel archwire static friction in active and passive self-ligating lingual and conventional brackets with second-order angulations.
  
  
  METHODS
  Two conventional lingual brackets for canines (STb light/Ormco; PSWb/Tecnident), and two self-ligating brackets, one active (In-Ovation L/GAC) and the other passive (3D/ Forestadent), were evaluated. A stainless steel archwire was used at 0°, 3° and 5° angulations. Metal ligatures, conventional elastic ligatures, and low friction elastic ligatures were also tested. A universal testing machine applied friction between brackets and wires, simulating sliding mechanics, to produce 2-mm sliding at 3 mm/minute speed.
  
  
  RESULTS
  Two-way analysis of variance demonstrated a significant effect of the interaction between brackets and angulations (p < 0.001). Tukey test indicated that the highest frictional resistance values were observed at 5° angulation for In-Ovation L, PSWb bracket with non conventional ligature, and STb bracket with metal ligature. As for 3D, PSWb with conventional or metal ligatures, and STb brackets with non conventional ligature, showed significantly lower static frictional resistance with 0° angulation. At 0° angulation, STb brackets with metal ties, In-Ovation L brackets and 3D brackets had the lowest frictional resistance.
  
  
  CONCLUSIONS
  As the angulation increased from 0° to 3°, static friction resistance increased. When angulation increased from 3° to 5°, static friction resistance increased or remained the same. Self-ligating 3D and In-Ovation L brackets, as well as conventional STb brackets, seem to be the best option when sliding mechanics is used to perform lingual orthodontic treatment.
authors.affiliation: Research Assistant, São Leopoldo Mandic, Department of Dental Material and Restorative Dentistry, School of Dentistry and Research Institute, Campinas, São Paulo, Brazil.
authors.forename: Graziane Olímpio
authors.initials: GO
authors.lastname: Pereira
authors.affiliation: Professor, Universidade de Araras (UNIARARAS), Department of Orthodontics, Araras, São Paulo Brazil. Universidade Estadual Paulista (FOA-UNESP), School of Dentistry, Department of Orthodontics, Araraquara, São Paulo, Brazil.
authors.forename: Carla Maria Melleiro
authors.initials: CM
authors.lastname: Gimenez
authors.affiliation: Private practice, Campo Grande, Mato Grosso do Sul, Brazil.
authors.forename: Lucas
authors.initials: L
authors.lastname: Prieto
authors.affiliation: Professor, São Leopoldo Mandic, Department of Dental Material and Restorative Dentistry, School of Dentistry and Research Institute, Campinas, São Paulo, Brazil.
authors.forename: Marcos Gabriel do Lago
authors.initials: MG
authors.lastname: Prieto
authors.affiliation: Professor, São Leopoldo Mandic, Department of Dental Material and Restorative Dentistry, School of Dentistry and Research Institute, Campinas, São Paulo, Brazil.
authors.forename: Roberta Tarkany
authors.initials: RT
authors.lastname: Basting
mesh_terms: D000818:Animals; D003799:Dental Stress Analysis; D004285:Dogs; D017276:Friction; D006801:Humans; D008026:Ligation; D008422:Materials Testing; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D013193:Stainless Steel
chemical_list: D013193:Stainless Steel