title: An assessment of the effectiveness of mechanical and chemical cleaning of Essix orthodontic retainer.
abstract: OBJECTIVE
  To determine the effectiveness of mechanical and chemical cleaning on the removal of microorganisms from Essix orthodontic retainers.
  
  
  METHODS
  In vitro laboratory study.
  
  
  METHODS
  Department of Orthodontics and Microbiology, Eastman Dental Institute, University College London, UK.
  
  
  METHODS
  Study 1: 120 Essix retainers were divided into four cleaning groups. The effectiveness of each cleaning method to remove a single species biofilm of Streptococcus mutans from the retainer was assessed. Study 2: 140 Essix retainers were divided into four study groups (brushing with fluoride toothpaste, chlorhexidine gel, immersion in chlorhexidine solution only and a control) to investigate the chemical and mechanical cleaning of the multispecies biolfilm of (Streptococcus sanguis, Actinomyces naeslundii, methicillin-resistant Staphylococcus aureus and Candida albicans).
  In study 1, brushing with toothpaste resulted in 99% reduction of Streptococcus mutans. In study 2, all three cleaning methods recorded similarly statistically significant reductions in colony forming units per millilitre compared to the control. There were no statistically significant differences between any of the cleaning groups for any of the microorganisms except MRSA-16. For MRSA-16, chlorhexidine mouthwash and gel were significantly more potent in eliminating the microorganism than the fluoride toothpaste.
  
  
  CONCLUSIONS
  All three cleaning methods effectively removed 99% of microorganisms from the Essix retainers. Brushing with fluoride toothpaste can therefore be confirmed as an effective method for cleaning retainers in most circumstances. The use of chlorhexidine gel or mouthwash is recommended in patients where bacterial infection has to be avoided due to immunosuppression or other reasons.
authors.affiliation: Orthodontic Department, Eastman Dental Institute, University College London, London, UK.
authors.forename: Chiew Sinn
authors.initials: CS
authors.lastname: Chang
authors.affiliation: Orthodontic Department, Eastman Dental Institute, University College London, London, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Al-Awadi
authors.affiliation: Microbiology Department, Eastman Dental Institute, University College London, London, UK.
authors.forename: Derren
authors.initials: D
authors.lastname: Ready
authors.affiliation: Orthodontic Department, Eastman Dental Institute, University College London, London, UK.
authors.forename: Joseph
authors.initials: J
authors.lastname: Noar
mesh_terms: D000190:Actinomyces / Q000187:drug effects / Q000502:physiology; D000891:Anti-Infective Agents, Local / Q000494:pharmacology; D058491:Bacterial Load / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects; D002176:Candida albicans / Q000187:drug effects / Q000502:physiology; D002710:Chlorhexidine / Q000008:administration & dosage / Q000494:pharmacology; D015169:Colony Count, Microbial; D004203:Disinfection / Q000379:methods*; D004866:Equipment Contamination / Q000517:prevention & control*; D005459:Fluorides / Q000494:pharmacology; D005782:Gels; D006801:Humans; D007101:Immersion; D008422:Materials Testing; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000502:physiology; D009067:Mouthwashes / Q000494:pharmacology; D018704:Orthodontic Retainers / Q000382:microbiology*; D013295:Streptococcus mutans / Q000187:drug effects / Q000502:physiology; D013298:Streptococcus sanguis / Q000187:drug effects / Q000502:physiology; D014099:Toothbrushing / Q000379:methods; D014100:Toothpastes / Q000494:pharmacology
chemical_list: D000891:Anti-Infective Agents, Local; D005782:Gels; D009067:Mouthwashes; D014100:Toothpastes; D005459:Fluorides; D002710:Chlorhexidine
keywords: Biofilm; chlorhexidine; cleaning; thermoplastic retainers; tooth brushing