title: Frictional resistance in plastic preadjusted brackets ligated with low-friction and conventional elastomeric ligatures.
abstract: OBJECTIVE
  To compare frictional resistance of the plastic preadjusted brackets ligated with the low-friction ligatures with those of the conventional elastomeric ligatures.
  
  
  METHODS
  In vitro study.
  
  
  METHODS
  Department of Orthodontics, Faculty of Dentistry, Kyushu University, Fukuoka, Japan.
  
  
  METHODS
  The testing model consisted of four 0.022-inch plastic preadjusted brackets for the first premolar, the canine, the lateral incisor, and the central incisor. A superelastic nickel-titanium 0.014-inch wire and a stainless steel 0.019 x 0.025-inch wire were used for this test. The brackets were either aligned or out of line by 0.5, 1.0, 1.5 and 2.0 mm for the 0.014-inch wire and aligned for the 0.019 x 0.025-inch wire. The frictional forces in plastic preadjusted brackets with low-friction ligatures and conventional elastomeric ligatures were measured at a pulling speed of 0.1 mm/second. Welch t-tests were used to compare the mean differences of each testing measurement between the low-friction and the conventional elastomeric ligatures.
  
  
  RESULTS
  In both use of the superelastic nickel-titanium 0.014-inch wire and the stainless steel 0.019 x 0.025-inch wire, the brackets with the low-friction ligatures showed significantly lower frictional forces than those of the conventional elastomeric ligatures in both aligned and all misaligned brackets (P < 0.0001).
  
  
  CONCLUSIONS
  The study found the significantly lower frictional forces for the low-friction ligatures than those of the conventional elastomeric ligatures.
authors.affiliation: Kyushu University, Fukuoka, Japan. ioi@dent.kyushu-u.ac.jp
authors.forename: Hideki
authors.initials: H
authors.lastname: Ioi
authors.forename: Yumi
authors.initials: Y
authors.lastname: Yanase
authors.forename: Michiya
authors.initials: M
authors.lastname: Uehara
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hara
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Nakata
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nakasima
authors.forename: Amy L
authors.initials: AL
authors.lastname: Counts
mesh_terms: D003722:Dental Alloys; D003799:Dental Stress Analysis; D020724:Elastomers; D017276:Friction; D006801:Humans; D009532:Nickel; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D010969:Plastics; D013193:Stainless Steel; D014025:Titanium
chemical_list: D003722:Dental Alloys; D020724:Elastomers; D010969:Plastics; C040654:titanium nickelide; D013193:Stainless Steel; D009532:Nickel; D014025:Titanium