title: Antimicrobial activity of Chlorhexidine, Peracetic acid and Sodium hypochlorite/etidronate irrigant solutions against Enterococcus faecalis biofilms.
abstract: OBJECTIVE
  To evaluate the antimicrobial effect of 2.5% sodium hypochlorite alone (NaOCl) and associated with 9% HEBP (NaOCl/HEBP), 2% peracetic acid (PAA) and 2% chlorhexidine (CHX), on the viability of Enterococcus faecalis biofilms attached to dentine.
  
  
  METHODS
  Biofilms of E. faecalis were grown on the surface of dentine blocks for 5 days and then exposed to the irrigating solutions for 3 min. Distilled water was used as the control. The total biovolume and the percentage of dead cells of the infected dentine were measured by means of confocal microscopy and the live/dead technique. Nonparametric tests were used to determine statistical differences (P < 0.05).
  
  
  RESULTS
  NaOCl and the NaOCl/HEBP mixture were associated with a significantly greater percentage of dead cells, followed by PAA (P < 0.05). No significant antimicrobial effect of CHX was observed in comparison with the control group. Total biovolume decreased significantly in NaOCl, NaOCl/HEBP and PAA solutions in comparison with the CHX and control groups.
  
  
  CONCLUSIONS
  NaOCl alone or associated with HEBP were the most effective irrigant solutions in dissolving and killing E. faecalis biofilms.
authors.affiliation: Department of Microbiology, School of Dentistry, University of Granada, Granada, Spain.
authors.forename: M T
authors.initials: MT
authors.lastname: Arias-Moliz
authors.affiliation: Department of Endodontics, Bauru Dental School, University of São Paulo, Bauru, Brazil.
authors.forename: R
authors.identifier: http://orcid.org/0000-0001-9738-0828
authors.initials: R
authors.lastname: Ordinola-Zapata
authors.affiliation: Department of Stomatology, School of Dentistry, University of Granada, Granada, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Baca
authors.affiliation: Department of Stomatology, School of Dentistry, University of Granada, Granada, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Ruiz-Linares
authors.affiliation: Department of Stomatology, School of Dentistry, University of Granada, Granada, Spain.
authors.forename: E
authors.initials: E
authors.lastname: García García
authors.affiliation: Department of Endodontics, Bauru Dental School, University of São Paulo, Bauru, Brazil.
authors.forename: M A
authors.initials: MA
authors.lastname: Hungaro Duarte
authors.affiliation: Department of Endodontics, Bauru Dental School, University of São Paulo, Bauru, Brazil.
authors.forename: C
authors.initials: C
authors.lastname: Monteiro Bramante
authors.affiliation: Department of Stomatology, School of Dentistry, University of Granada, Granada, Spain.
authors.forename: C M
authors.initials: CM
authors.lastname: Ferrer-Luque
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D002710:Chlorhexidine / Q000494:pharmacology*; D003804:Dentin / Q000382:microbiology*; D013293:Enterococcus faecalis / Q000187:drug effects*; D012968:Etidronic Acid / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D018613:Microscopy, Confocal; D010463:Peracetic Acid / Q000494:pharmacology*; D012388:Root Canal Irrigants / Q000494:pharmacology*; D012973:Sodium Hypochlorite / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D050071:Bone Density Conservation Agents; D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite; D010463:Peracetic Acid; D012968:Etidronic Acid; D002710:Chlorhexidine
keywords: antimicrobials; bacteria; dentine infection; root canal irrigants