title: Antimicrobial effect of a modified vanadium chloroperoxidase on Enterococcus faecalis biofilms at root canal pH.
abstract: BACKGROUND
  Previous research showed an antimicrobial effect of vanadium chloroperoxidase (VCPO) on in vitro Enterococcus faecalis biofilms. The current study aimed to optimize the use of this enzyme at the root canal pH using a modified VCPO (mVCPO) that was adapted to function at a higher pH and to explore the biocompatibility of mVCPO.
  
  
  METHODS
  The activity of the original and modified VCPO was assessed using the monochlorodimedone assay. For antimicrobial assessment, 48-hour biofilms of E. faecalis OS-16 were incubated 5 or 30 minutes with mVCPO, bromide, and hydrogen peroxide, and colony-forming units were determined. A metabolic activity assay was used to evaluate the cytotoxic effect of mVCPO on oral fibroblasts.
  
  
  RESULTS
  Reaction products generated by mVCPO at a root canal pH of 7.7 significantly inactivated the biofilm after 5 minutes and even more after 30 minutes (Mann-Whitney U test, P < .05). The mVCPO reaction products showed less cytotoxic effects than control solutions and 0.5% sodium hypochlorite (Kruskal-Wallis test, P < .05).
  
  
  CONCLUSIONS
  The incubation of mVCPO in the presence of its substrates with in vitro E. faecalis biofilms showed a significant antimicrobial effect at the root canal pH. Also, cytotoxicity tests showed preliminary biocompatibility. Therefore, an interappointment dressing containing mVCPO could aid in improving current endodontic treatment through continuous and local generation of antimicrobials.
authors.affiliation: Department of Conservative and Preventive Dentistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and VU University, Amsterdam, The Netherlands. i.persoon@acta.nl
authors.forename: Ilona F
authors.initials: IF
authors.lastname: Persoon
authors.forename: Michel A
authors.initials: MA
authors.lastname: Hoogenkamp
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Bury
authors.forename: Paul R
authors.initials: PR
authors.lastname: Wesselink
authors.forename: Aloysius F
authors.initials: AF
authors.lastname: Hartog
authors.forename: Ronald
authors.initials: R
authors.lastname: Wever
authors.forename: Wim
authors.initials: W
authors.lastname: Crielaard
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000633:toxicity; D001672:Biocompatible Materials / Q000494:pharmacology / Q000633:toxicity; D018441:Biofilms / Q000187:drug effects*; D001965:Bromides / Q000494:pharmacology; D002711:Chloride Peroxidase / Q000494:pharmacology* / Q000633:toxicity; D003512:Cyclohexanones; D003786:Dental Pulp Cavity / Q000187:drug effects / Q000382:microbiology*; D013293:Enterococcus faecalis / Q000187:drug effects*; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D009061:Mouth Mucosa / Q000166:cytology / Q000187:drug effects; D016877:Oxidants / Q000494:pharmacology; D012388:Root Canal Irrigants / Q000494:pharmacology / Q000633:toxicity; D012973:Sodium Hypochlorite / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D001672:Biocompatible Materials; D001965:Bromides; D003512:Cyclohexanones; D016877:Oxidants; D012388:Root Canal Irrigants; C006991:chlorodimedone; D006861:Hydrogen Peroxide; D012973:Sodium Hypochlorite; C418625:vanadium chloroperoxidase; D002711:Chloride Peroxidase
keywords: Antimicrobial agents; Enterococcus faecalis; biofilms; cytotoxicity; hypohalite; pH; vanadium chloroperoxidase