title: Observations of biofilm growth on human dentin and potential destruction after exposure to antibiotics.
abstract: OBJECTIVE
  This study was performed to observe biofilm formation on dentin and to then observe effects of clinically achievable antimicrobial drug concentrations on these biofilms.
  
  
  METHODS
  Wild-strain endodontic bacteria were anaerobically cultured from necrotic pulps of extracted human teeth and used to grow biofilms on sterilized dentin slices in an anaerobic chamber for 12 days. Then these biofilms were exposed to ampicillin, doxycycline, clindamycin, azithromycin, or metronidazole. Each day for 8 days, specimens were fixed using 2% glutaraldehyde and examined with a scanning electron microscope (SEM).
  
  
  RESULTS
  The SEM images revealed the presence of a mature biofilm after 8 days of growth and that none of the antibiotics tested was effective in eliminating the biofilm even after 8 days of exposure.
  
  
  CONCLUSIONS
  Biofilms are formed in a few days and are resistant to antimicrobial drugs.
authors.affiliation: Department of Endodontics, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
authors.forename: David W
authors.initials: DW
authors.lastname: Norrington
authors.forename: John
authors.initials: J
authors.lastname: Ruby
authors.forename: Preston
authors.initials: P
authors.lastname: Beck
authors.forename: Paul D
authors.initials: PD
authors.lastname: Eleazer
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging / Q000382:microbiology*; D003790:Dental Pulp Necrosis / Q000000981:diagnostic imaging / Q000382:microbiology; D003804:Dentin; D024881:Drug Resistance, Bacterial; D006801:Humans; D011859:Radiography
chemical_list: D000900:Anti-Bacterial Agents