title: [Comparison of friction force between Lock-loose bracket and traditional bracket].
abstract: OBJECTIVE
  Frictions of Lock-loose brackets with ligated main wings or all six wings were measured as they slid along archwires in dry and artificial saliva environments. The Lock-loose brackets were then compared with traditional brackets and self-ligating brackets.
  
  
  METHODS
  The surface states of the stainless steel archwires were observed with atomic force microscopy before and after mechanical traction. The Lock-loose brackets, traditional brackets, and self-ligating brackets used in this study were composed of 0.406 4 and 0.457 2 mm stainless steel round archwires and 0.457 2 mm x 0.634 9 mm and 0.482 6 mm x 0.634 9 mm stainless steel rectangular archwires. Two different ligating methods were applied to the Lock-loose brackets, i.e., main wings ligated and all six wings ligated. Frictions were measured by using an electronic universal testing machine.
  
  
  RESULTS
  No significant differences were found between the roughness of different archwires before and after mechanical traction in different brackets (P > 0.05). When the main wings of the Lock-loose brackets were ligated, the frictions of the four different stainless steel archwires were close to zero, and the difference with frictions of traditional brackets was significant (P < 0.05). When using 0.457 2 mm x 0.634 9 mm rectangular archwires, maximum friction (P < 0.05; significantly different from those of other brackets) was reached when all six wings of the Lock-loose brackets were ligated. Frictions in the dry state were higher than those in the wet state (P < 0.05).
  
  
  CONCLUSIONS
  The Lock-loose brackets can adjust the friction efficiently with different ligating methods, thus solving the problem of low friction and strengthening anchorage.
authors: Liu
authors: L
authors: Xiaowei
authors: Yang
authors: Y
authors: Luyi
authors: Zhu
authors: Z
authors: Huifang
authors: Dong
authors: D
authors: Yan
authors: Wang
authors: W
authors: Qi
authors: Jiang
authors: J
authors: Wei
authors: Wu
authors: W
authors: Yanran
mesh_terms: D017276:Friction; D006801:Humans; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D013193:Stainless Steel; D013499:Surface Properties
chemical_list: D013193:Stainless Steel