title: Effect of 0.4% stannous fluoride gel on Streptococci mutans in relation to elastomeric rings and steel ligatures in orthodontic patients.
abstract: BACKGROUND
  Patients with fixed orthodontic appliances often experience an absolute increase in the number of Streptococci mutans colony-forming units (cfu). The aim of this investigation was to study the development of biofilm and S. mutans cfu in connection with stainless steel ligatures and elastomeric rings in orthodontic patients treated with and without 0.4% stannous fluoride gel (SFG).
  
  
  METHODS
  Forty-seven patients were divided into 2 groups: those treated with 0.4% SFG for 4 minutes (experimental) and those without 0.4% SFG (control). In each patient, elastomeric rings were used for ligation on 1 side of the dental arch midline, and stainless steel ligatures were used on the opposite side. Saliva samples were collected before and after appliance placement. At 15 and 30 days after appliance placement, biofilm samples from the stainless steel ligatures and the elastomeric rings were collected and subjected to microbiologic procedures and scanning electron microscopy (SEM) analysis.
  
  
  RESULTS
  The numbers of S. mutans cfu in the saliva and biofilm were not statistically different between the teeth fitted with elastomeric rings and stainless steel ligatures, or between the experimental and control groups. SEM analysis showed biofilm formation on both ligature ties.
  
  
  CONCLUSIONS
  Topical application of 0.4% SFG in orthodontic patients with elastomeric rings or stainless steel ligatures does not cause a significant decrease in S. mutans cfu in the saliva and biofilm.
authors.affiliation: Department of Pediatric Dentistry, Faculty of Dentistry of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Sabryna Maria
authors.initials: SM
authors.lastname: Brêtas
authors.forename: Soraia
authors.initials: S
authors.lastname: Macari
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Elias
authors.forename: Izabel Yoko
authors.initials: IY
authors.lastname: Ito
authors.forename: Mírian Aiko Nakane
authors.initials: MA
authors.lastname: Matsumoto
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D018441:Biofilms / Q000187:drug effects*; D002327:Cariostatic Agents / Q000008:administration & dosage*; D002648:Child; D015169:Colony Count, Microbial; D003773:Dental Plaque / Q000209:etiology / Q000382:microbiology*; D020724:Elastomers / Q000009:adverse effects; D005260:Female; D005782:Gels; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D009967:Orthodontic Appliances / Q000009:adverse effects*; D009969:Orthodontic Wires / Q000009:adverse effects; D012463:Saliva / Q000382:microbiology; D013295:Streptococcus mutans / Q000187:drug effects*; D014002:Tin Fluorides / Q000008:administration & dosage*
chemical_list: D002327:Cariostatic Agents; D020724:Elastomers; D005782:Gels; D014002:Tin Fluorides