title: The effect of dentifrice abrasion on denture topography and the subsequent retention of microorganisms on abraded surfaces.
abstract: BACKGROUND
  Denture surfaces provide hard nonshedding niches for the adhesion and subsequent accumulation of oral microorganisms into denture plaque, which can harbor various potential pathogens linked with oral mucosal lesions and inhalation pneumonia. The initial adhesion is the prerequisite for subsequent biofilm growth, and surface roughness niches facilitate this process by trapping cells. Retained microorganisms are then able to proliferate when the denture is returned to the oral cavity.
  
  
  OBJECTIVE
  The purpose of this study was to measure the amount and strength of the attachment of microorganisms to a roughened denture acrylic resin surface. An increase in surface roughness increases the retention of microorganisms and a greater amount of cell-surface contact interface may increase the strength of adhesion and, therefore, retention. Cleaning denture surfaces with brushes and dentifrices can influence the denture surface topography and, therefore, may affect retention.
  
  
  METHODS
  Denture acrylic resin specimens were abraded to provide different surface roughness. The amount of attachment of Streptococcus oralis or Candida albicans to these surfaces was assessed by measuring the area of a microscopic field covered by stained cells after 1 hour of incubation. The strength of attachment was assessed with atomic force microscopy, whereby an increasing force was applied to the attached cells until they detached from the surface.
  
  
  RESULTS
  Both bacteria and yeast cells were retained in increasing amounts on surfaces of increasing roughness. Cells were most strongly attached on surfaces whose linear features (scratches) were of comparable size with the cells (the streptococci on the low-abraded surfaces, and the yeast on high-abraded surfaces).
  
  
  CONCLUSIONS
  Analysis of findings reveal that even small abrasions may enhance retention on denture surfaces and reduce surface cleanability. The strength of attachment instead of the amount is more important in terms of surface hygiene.
authors.affiliation: Professor, School of Health Care Science, Manchester Metropolitan University, Manchester, UK. Electronic address: j.verran@mmu.ac.uk.
authors.forename: Joanna
authors.initials: J
authors.lastname: Verran
authors.affiliation: Former doctoral student, School of Health Care Science, Manchester Metropolitan University, Manchester, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Jackson
authors.affiliation: Senior Lecturer in microbiology, School of Health Care Science, Manchester Metropolitan University, Manchester, UK.
authors.forename: Lisa
authors.initials: L
authors.lastname: Coulthwaite
authors.affiliation: Senior Lecturer, School of Computing, Mathematics and Digital Technology, Manchester Metropolitan University, Manchester, UK.
authors.forename: Anthony
authors.initials: A
authors.lastname: Scallan
authors.affiliation: Professor, Department of Pharmaceutical and Biomedical Sciences, Touro College of Pharmacy, NY; Professor, Department of Microbiology and Immunology, New York Medical College, Valhalla, NY.
authors.forename: Zvi
authors.initials: Z
authors.lastname: Loewy
authors.affiliation: Reader, School of Health Care Science, Manchester Metropolitan University, Manchester, UK.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Whitehead
mesh_terms: D001422:Bacterial Adhesion / Q000502:physiology; D058491:Bacterial Load; D018441:Biofilms; D002176:Candida albicans / Q000502:physiology; D015169:Colony Count, Microbial; D003764:Dental Materials / Q000737:chemistry*; D003773:Dental Plaque / Q000382:microbiology; D003802:Dentifrices / Q000737:chemistry*; D003778:Dentures / Q000382:microbiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D008856:Microscopy, Fluorescence; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D019533:Streptococcus oralis / Q000502:physiology; D013499:Surface Properties; D013997:Time Factors
chemical_list: D003764:Dental Materials; D003802:Dentifrices; D019904:Polymethyl Methacrylate