title: Incorporation of staphylococci into titanium-grown biofilms: an in vitro "submucosal" biofilm model for peri-implantitis.
abstract: OBJECTIVE
  Staphylococcus spp. are postulated to play a role in peri-implantitis. This study aimed to develop a "submucosal" in vitro biofilm model, by integrating two staphylococci into its composition.
  
  
  METHODS
  The standard "subgingival" biofilm contained Actinomyces oris, Fusobacterium nucleatum, Streptococcus oralis, Veillonella dispar, Campylobacter rectus, Prevotella intermedia, Streptococcus anginosus, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola, and was further supplemented with Staphyoccous aureus and/or Staphylococcus epidermidis. Biofilms were grown anaerobically on hydroxyapatite or titanium discs and harvested after 64 h for real-time polymerase chain reaction, to determine their composition. Confocal laser scanning microscopy and fluorescence in situ hybridization were used for identifying the two staphylococci within the biofilm.
  
  
  RESULTS
  Both staphylococci established within the biofilms when added separately. However, when added together, only S. aureus grew in high numbers, whereas S. epidermidis was reduced almost to the detection limit. Compared to the standard subgingival biofilm, addition of the two staphylococci had no impact on the qualitative or quantitative composition of the biofilm. When grown individually in the biofilm, S. epidermidis and S. aureus formed small distinctive clusters and it was confirmed that S. epidermidis was not able to grow in presence of S. aureus.
  
  
  CONCLUSIONS
  Staphyoccous aureus and S. epidermidis can be individually integrated into an oral biofilm grown on titanium, hence establishing a "submucosal" biofilm model for peri-implantitis. This model also revealed that S. aureus outcompetes S. epidermidis when grown together in the biofilm, which may explain the more frequent association of the former with peri-implantitis.
authors.affiliation: Section of Oral Microbiology and Immunology, Institute of Oral Biology, Center of Dental Medicine, University of Zürich, Zürich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Thurnheer
authors.affiliation: Section of Oral Microbiology and Immunology, Institute of Oral Biology, Center of Dental Medicine, University of Zürich, Zürich, Switzerland.
authors.forename: Georgios N
authors.initials: GN
authors.lastname: Belibasakis
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D005881:Gingiva / Q000382:microbiology; D006801:Humans; D066298:In Vitro Techniques; D008954:Models, Biological; D057873:Peri-Implantitis / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000254:growth & development*; D013212:Staphylococcus epidermidis / Q000254:growth & development*; D014025:Titanium
chemical_list: D014025:Titanium
keywords: biofilms; in vitro model; peri-implantitis; titanium surface