title: Evaluation of the co-existence of the red fluorescent plaque bacteria P. gingivalis with S. gordonii and S. mutans in white spot lesion formation during orthodontic treatment.
abstract: BACKGROUND
  Early detection of white spot lesions (WSLs) around brackets during orthodontic treatment is important for treatment and prevention. But it is unclear whether red fluorescent plaque (RFP) bacteria Porphyromonas gingivalis and its co-existence with Streptococcus mutans and Streptococcus gordonii has any significant influence on this. Therefore the role of this bacterial co existence and WSLs formation during one year of fixed orthodontic therapy was evaluated.
  
  
  METHODS
  Fourteen 12 to 22 year old (mean 15 ± 3 years) consecutive patients attending the University of Liverpool dental hospital were recruited for this study. Quantitative Light-induced Fluorescence (QLF) was used to identify RFP and enamel demineralisation, respectively, on anterior labial surfaces before and after placement of fixed orthodontic appliances. Bacterial composition was determined by denaturing gradient gel electrophoresis (DGGE) following nested PCR amplification of the 16S rRNA V2-V3 hypervariable region.
  
  
  RESULTS
  WSLs were recorded on 4.2% of tooth surfaces and WSL development was not associated with RFP bacteria P. gingivalis presence. Differences in RFP bacteria P. gingivalis presence with S. mutans and S. gordonii, were observed before and after appliance placement. Intra subject changes in plaque flora between visits were not significantly associated with WSL development (p > 0.05). However, DGGE profiles indicated that apart from S. mutans, S. gordonii might also have a role in human enamel demineralisation.
  
  
  CONCLUSIONS
  Fixed orthodontic brackets in adolescents may play a role in altering bacterial composition around brackets during orthodontic treatment and it is plausible that S. gordonii also have a role in human enamel demineralisation. Combinatorial approach of QLF technology and DGGE may be useful in determining bacterial composition during orthodontic therapy which could inform clinical interventions.
authors: Department of Health Services Research and School of Dentistry, University of Liverpool, Research Wing, Daulby Street, Liverpool L69 3GN, United Kingdom.
authors: Amal
authors: A
authors: Sadeq
authors: Department of Molecular and Clinical Cancer Medicine and School of Dentistry, University of Liverpool, Research Wing, Daulby Street, Liverpool L69 3GN, United Kingdom.
authors: Janet M
authors: JM
authors: Risk
authors: Department of Health Services Research and School of Dentistry, University of Liverpool, Research Wing, Daulby Street, Liverpool L69 3GN, United Kingdom.
authors: Neil
authors: N
authors: Pender
authors: Department of Health Services Research and School of Dentistry, University of Liverpool, Research Wing, Daulby Street, Liverpool L69 3GN, United Kingdom.
authors: Susan M
authors: SM
authors: Higham
authors: Department of Health Services Research and School of Dentistry, University of Liverpool, Research Wing, Daulby Street, Liverpool L69 3GN, United Kingdom. Electronic address: S.Valappil@liv.ac.uk.
authors: Sabeel P
authors: SP
authors: Valappil
mesh_terms: D000293:Adolescent; D002648:Child; D003773:Dental Plaque / Q000382:microbiology*; D004587:Electrophoresis, Agar Gel; D005260:Female; D006801:Humans; D008297:Male; D016910:Orthodontic Brackets / Q000382:microbiology; D010778:Photochemotherapy / Q000379:methods*; D016133:Polymerase Chain Reaction; D016966:Porphyromonas gingivalis / Q000166:cytology*; D012336:RNA, Ribosomal, 16S; D054773:Streptococcus gordonii / Q000166:cytology*; D013295:Streptococcus mutans / Q000166:cytology*; D017001:Tooth Demineralization / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D012336:RNA, Ribosomal, 16S
keywords: Denaturing gradient gel electrophoresis; Dental caries; Dental plaque; Quantitative light-induced fluorescence