title: In vitro and in vivo biofilm adhesion to esthetic coated arch wires and its correlation with surface roughness.
abstract: OBJECTIVE
  To evaluate the in vitro ability of esthetic coated rectangular arch wires to retain oral biofilms and in vivo biofilm formation on these wires after 4 and 8 weeks of clinical use and to correlate the findings with the surface roughness of these wires.
  
  
  METHODS
  Three brands of esthetic coated nickel-titanium (NiTi) arch wires were selected. Arch wires retrieved after 4 and 8 weeks of intraoral use were obtained from 30 orthodontic patients. Surface roughness (SR) was assessed with an atomic force microscope. In vitro adhesion assays were performed using Streptococcus mutans (MS), Staphylococcus aureus, and Candida albicans. The amount of bacterial adhesion was quantified using the colony-count method. Paired t-test, analysis of variance, post hoc Tukey's test, and Pearson's correlation coefficient test were used for statistical analysis at the .05 level of significance.
  
  
  RESULTS
  In vitro bacterial adhesion showed significant differences between wires in terms of MS adhesion (P  =  .01). All wires showed significant increases in SR (P  =  .001 after 4 weeks and .007 after 8 weeks) and biofilm adhesion (P  =  .0001 after 4 weeks and .045 after 8 weeks) after intraoral exposure. A significant positive correlation (P  =  .001 after 4 weeks and .05 after 8 weeks) was observed between these two variables in vivo, but the correlation was not significant for in vitro bacterial adhesion.
  
  
  CONCLUSIONS
  SR and biofilm adhesion increased after intraoral use at all time intervals. There was a positive correlation between SR and biofilm adhesion in vivo only.
authors.affiliation: a  Associate Professor of Orthodontics, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
authors.forename: Mahasen
authors.initials: M
authors.lastname: Taha
authors.affiliation: b  Professor of Dental Biomaterials, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
authors.forename: Abeer
authors.initials: A
authors.lastname: El-Fallal
authors.affiliation: c  Lecturer, Microbiology and Immunology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
authors.forename: Heba
authors.initials: H
authors.lastname: Degla
mesh_terms: D001422:Bacterial Adhesion; D018441:Biofilms; D002176:Candida albicans; D003722:Dental Alloys; D004955:Esthetics, Dental; D006801:Humans; D008422:Materials Testing; D009532:Nickel; D009969:Orthodontic Wires; D013211:Staphylococcus aureus; D013295:Streptococcus mutans; D013499:Surface Properties; D014025:Titanium
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium
keywords: Biofilm adhesion; Esthetic wires; Surface roughness