title: Antimicrobial effects of carbamide peroxide against a polymicrobial biofilm model.
abstract: OBJECTIVE
  To investigate the in vitro antimicrobial effects of carbamide peroxide (CP) and CP-based home bleaching agents against polymicrobial (PM) biofilms.
  
  
  METHODS
  Using a high-throughput active attachment model, PM biofilms were cultured on glass coverslips by diluting the stimulated saliva of one healthy adult. All experiments were performed anaerobically in McBain medium, which was refreshed twice daily. After biofilm formation for 24 or 72 hours, the biofilms were treated with 0.5%, 2.5%, 5%, or 10% CP, 20-fold dilutions of HiLite Shade Up (HS) or Opalescence Regular (OR), 0.2% chlorhexidine digluconate (CHX), 0.2% NaF, or deionized water (n = 10 each). Biofilms were dispersed and the number of colony forming units (CFU) was measured on tryptic soy agar blood plates. Coverslips containing 72-hour biofilms treated with 0.5% and 10% CP and deionized water were stained and scanned by confocal laser scanning microscopy (CLSM).
  
  
  RESULTS
  Treatment of 24- and 72-hour biofilms with HS, OR and CH yielded significantly fewer colonies than treatment with water or 0.2% NaF. No growing colonies were observed after treatment with 10% CP. CLSM showed that the percentage of dead bacteria increased as the concentration of CP increased.
authors: Haruhiko
authors: H
authors: Hasegawa
authors: Kiyoshi
authors: K
authors: Tomiyama
authors: Hidefumi
authors: H
authors: Kumada
authors: Akira
authors: A
authors: Kawata
authors: Kazuyoshi
authors: K
authors: Higashi
authors: Osamu
authors: O
authors: Takahashi
authors: Nobushiro
authors: N
authors: Hamada
authors: Yoshiharu
authors: Y
authors: Mukai
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000891:Anti-Infective Agents, Local / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects*; D058491:Bacterial Load / Q000187:drug effects; D001431:Bacteriological Techniques; D018441:Biofilms / Q000187:drug effects*; D000077463:Carbamide Peroxide; D002327:Cariostatic Agents / Q000494:pharmacology; D002710:Chlorhexidine / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D008422:Materials Testing; D018613:Microscopy, Confocal; D010545:Peroxides / Q000008:administration & dosage / Q000494:pharmacology*; D012463:Saliva / Q000382:microbiology; D012969:Sodium Fluoride / Q000494:pharmacology; D013997:Time Factors; D058205:Tooth Bleaching Agents / Q000008:administration & dosage / Q000494:pharmacology*; D014508:Urea / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D000891:Anti-Infective Agents, Local; D002327:Cariostatic Agents; D010545:Peroxides; D058205:Tooth Bleaching Agents; D000077463:Carbamide Peroxide; D014508:Urea; D012969:Sodium Fluoride; C010882:chlorhexidine gluconate; D002710:Chlorhexidine