title: Changes in the subgingival microbiota and periodontal parameters before and 3 months after bracket placement.
abstract: BACKGROUND
  Dental plaque is organized in a biofilm complex that provides protection and nutrients for periodontopathic bacteria. Several factors can affect microbial colonization, including restorations and orthodontic brackets. The aim of this study was to investigate changes in subgingival microbiota and clinical parameters before and after bracket placement.
  
  
  METHODS
  Clinical parameters and subgingival microbial samples were collected from 30 patients before and after bracket placement. Thirty additional patients with no orthodontic treatment served as controls. Samples were cultured and analyzed for periodontopathic and superinfecting bacteria. A descriptive analysis was conducted, and chi-square, Student t, Wilcoxon matched, and Mann Whitney rank sum tests were used to test for differences between groups (P < or=.05).
  
  
  RESULTS
  No changes in probing depth or clinical attachment level were observed, but scores for bleeding on probing, plaque index, and gingival index increased after bracket placement (P < or =.05). Porphyromonas gingivalis, Prevotella intermedia/Prevotella nigrescens, Tannerella forsythia, and Fusobacterium species were elevated in the experimental group after bracket placement compared with the control group (P < or =.01). Superinfecting microorganisms such as Enterobacter cloacae, Klebsiella oxytoca, Klebsiella pneumoniae, and Serratia marcescens were also found.
  
  
  CONCLUSIONS
  Bracket placement influences the accumulation of plaque and the colonization of important periodontopathic and superinfecting bacteria, resulting in more inflammation and bleeding. Special attention should be paid to oral hygiene methods in orthodontic patients.
authors.affiliation: Resident, Department of Orthodontics, Colegio Odontológico Colombiano, Cali, Colombia.
authors.forename: Andrea Amezquita
authors.initials: AA
authors.lastname: Naranjo
authors.forename: Martha Lucia
authors.initials: ML
authors.lastname: Triviño
authors.forename: Adriana
authors.initials: A
authors.lastname: Jaramillo
authors.forename: Marisol
authors.initials: M
authors.lastname: Betancourth
authors.forename: Javier Enrique
authors.initials: JE
authors.lastname: Botero
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D003773:Dental Plaque / Q000209:etiology / Q000382:microbiology*; D003774:Dental Plaque Index; D005260:Female; D005891:Gingivitis / Q000209:etiology / Q000382:microbiology*; D016965:Gram-Negative Anaerobic Straight, Curved, and Helical Rods / Q000302:isolation & purification; D006801:Humans; D008297:Male; D016910:Orthodontic Brackets / Q000009:adverse effects*; D010512:Periodontal Index; D018709:Statistics, Nonparametric