title: Biofilm retention by 3 methods of ligation on orthodontic brackets: a microbiologic and optical coherence tomography analysis.
abstract: BACKGROUND
  The aim of this study was to evaluate biofilm retention around orthodontic brackets related to the method of ligation by using optical coherence tomography (OCT) and microbiologic sampling.
  
  
  METHODS
  Seventy-five plastic central incisors for dentures were divided into 3 groups and used with metal brackets with a 0.022-in slot with elastomeric ligature (n = 25), metal brackets with a 0.022-in slot with steel wire ligature (n = 25), and self-ligating brackets with a 0.022-in slot (n = 25). The samples were submersed in a suspension of Streptococcus mutans, genetically engineered to express green fluorescent protein, at 37°C for 72 hours to allow biofilm formation. The samples were then submitted to microbiologic analysis and OCT imaging.
  
  
  RESULTS
  The microbiologic analysis and the OCT showed significant differences in biofilm formation depending on the ligating method. Brackets ligated with elastomeric rings held more S mutans biofilm, and steel wire ligation had less biofilm retention compared with the other brackets.
  
  
  CONCLUSIONS
  This study provided validation that OCT can be used as a potential qualitative marker of total plaque bacteria that can be rapidly and reliably visualized around orthodontic brackets.
authors.affiliation: Department of Orthodontics, St Leopoldo Mandic Dental Research Center, Campinas, São Paulo, Brazil. garcez.segundo@gmail.com
authors.forename: Aguinaldo S
authors.initials: AS
authors.lastname: Garcez
authors.forename: Selly S
authors.initials: SS
authors.lastname: Suzuki
authors.forename: Martha S
authors.initials: MS
authors.lastname: Ribeiro
authors.forename: Edson Y
authors.initials: EY
authors.lastname: Mada
authors.forename: Anderson Z
authors.initials: AZ
authors.lastname: Freitas
authors.forename: Hideo
authors.initials: H
authors.lastname: Suzuki
mesh_terms: D001431:Bacteriological Techniques; D018441:Biofilms / Q000254:growth & development*; D003722:Dental Alloys / Q000737:chemistry; D020724:Elastomers / Q000737:chemistry; D049452:Green Fluorescent Proteins; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007180:Incisor / Q000382:microbiology; D049408:Luminescent Agents; D018613:Microscopy, Confocal; D016910:Orthodontic Brackets / Q000145:classification / Q000382:microbiology*; D009969:Orthodontic Wires / Q000382:microbiology; D013232:Steel / Q000737:chemistry; D013295:Streptococcus mutans / Q000502:physiology; D013696:Temperature; D013997:Time Factors; D041623:Tomography, Optical Coherence / Q000379:methods*; D014093:Tooth, Artificial / Q000382:microbiology
chemical_list: D003722:Dental Alloys; D020724:Elastomers; D049408:Luminescent Agents; D013232:Steel; D049452:Green Fluorescent Proteins