title: Streptococcus mutans adhesion on nickel titanium (NiTi) and copper-NiTi archwires: A comparative prospective clinical study.
abstract: OBJECTIVE
  To compare the adhesion of Streptococcus mutans to nickel titanium (NiTi) and copper-NiTi (Cu-NiTi) archwires and to correlate the adhesion to surface characteristics (surface free energy and surface roughness) of these wires.
  
  
  METHODS
  A total of 16 patients undergoing orthodontic treatment with preadjusted edgewise appliances were included in the study. 0.016" and 0.016" × 0.022" NiTi and Cu-NiTi archwires in as-received condition and after 4 weeks of intraoral use were studied for S mutans adhesion using real-time polymerase chain reaction. Surface roughness and surface free energy were studied by three-dimensional surface profilometry and dynamic contact angle analysis, respectively.
  
  
  RESULTS
  S mutans adhesion was more in Cu-NiTi archwires. These wires exhibited rougher surface and higher surface free energy when compared to NiTi archwires.
  
  
  CONCLUSIONS
  S mutans adhesion, surface roughness, and surface free energy were greater in Cu-NiTi than NiTi archwires. Surface roughness and surface free energy increased after 4 weeks of intraoral exposure for all of the archwires studied. A predominantly negative correlation was seen between the cycle threshold value of adherent bacteria and surface characteristics.
authors.forename: Kirubaharan S
authors.initials: KS
authors.lastname: Abraham
authors.forename: Nithya
authors.initials: N
authors.lastname: Jagdish
authors.forename: Vignesh
authors.initials: V
authors.lastname: Kailasam
authors.forename: Sridevi
authors.initials: S
authors.lastname: Padmanabhan
mesh_terms: D001422:Bacterial Adhesion; D003300:Copper / Q000737:chemistry*; D006801:Humans; D021621:Imaging, Three-Dimensional; D009532:Nickel / Q000737:chemistry*; D009969:Orthodontic Wires; D011446:Prospective Studies; D060888:Real-Time Polymerase Chain Reaction; D013295:Streptococcus mutans; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: C040654:titanium nickelide; D003300:Copper; D009532:Nickel; D014025:Titanium
keywords: Adhesion; Cu NiTi; NiTi; Roughness; S mutans