title: Effects of Dentin Debris on the Antimicrobial Properties of Sodium Hypochlorite and Etidronic Acid.
abstract: BACKGROUND
  The purpose of this study was to determine the influence of dentin powder on the concentration, pH, and antimicrobial activity of sodium hypochlorite (NaOCl) alone and combined with etidronic acid (HEBP).
  
  
  METHODS
  Biofilms of Enterococcus faecalis were grown on the surface of dentin blocks for 5 days and then exposed to 1% and 2.5% NaOCl alone or combined with 9% HEBP for 3 minutes in the absence and presence of dentin powder. The biovolumes of the biofilm were measured using confocal microscopy and the live/dead technique. The available chlorine and pH of the solutions were also measured. Nonparametric tests were used to determine statistical differences (P < .05).
  
  
  RESULTS
  The presence of dentin powder resulted in a reduction of the free available chlorine and pH in all the irrigating solutions; 1% NaOCl lost its antimicrobial activity completely in the presence of dentin powder. The antimicrobial activity was significantly reduced in the 2.5% NaOCl and 1% NaOCl/HEBP groups, and it was not affected in the 2.5% NaOCl/HEBP group.
  
  
  CONCLUSIONS
  The presence of dentin powder significantly decreased the available chlorine and antimicrobial activity of 1% NaOCl, 2.5% NaOCl, and 1% NaOCl/HEBP irrigating solutions. The antimicrobial activity of 2.5% NaOCl/HEBP was not affected by the dentin powder after a 3-minute contact time against E. faecalis biofilms.
authors.affiliation: Department of Microbiology, School of Dentistry, University of Granada, Spain. Electronic address: mtarias@ugr.es.
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Arias-Moliz
authors.affiliation: Department of Microbiology, School of Dentistry, University of Granada, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Morago
authors.affiliation: Department of Endodontics, Bauru Dental School, University of São Paulo, São Paulo, Brazil.
authors.forename: Ronald
authors.initials: R
authors.lastname: Ordinola-Zapata
authors.affiliation: Department of Stomatology, School of Dentistry, University of Granada, Spain.
authors.forename: Carmen María
authors.initials: CM
authors.lastname: Ferrer-Luque
authors.affiliation: Department of Stomatology, School of Dentistry, University of Granada, Spain.
authors.forename: Matilde
authors.initials: M
authors.lastname: Ruiz-Linares
authors.affiliation: Department of Stomatology, School of Dentistry, University of Granada, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Baca
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development; D002713:Chlorine / Q000032:analysis; D003804:Dentin / Q000737:chemistry* / Q000382:microbiology; D004338:Drug Combinations; D013293:Enterococcus faecalis / Q000187:drug effects / Q000254:growth & development; D012968:Etidronic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D018613:Microscopy, Confocal; D012388:Root Canal Irrigants / Q000494:pharmacology; D012973:Sodium Hypochlorite / Q000008:administration & dosage / Q000494:pharmacology*; D014867:Water
chemical_list: D000890:Anti-Infective Agents; D004338:Drug Combinations; D012388:Root Canal Irrigants; D014867:Water; D002713:Chlorine; D012973:Sodium Hypochlorite; D012968:Etidronic Acid
keywords: Antimicrobial activity; dentin debris; etidronic acid; root canal irrigants; sodium hypochlorite