title: Biofilm dissolution and cleaning ability of different irrigant solutions on intraorally infected dentin.
abstract: BACKGROUND
  The aim of this study was to evaluate the biofilm dissolution and cleaning ability of different irrigant solutions on intraorally infected dentin.
  
  
  METHODS
  One hundred twenty bovine dentin specimens were infected intraorally by using a removable orthodontic device. Thirty samples were used for each irrigant solution: 2% chlorhexidine and 1%, 2.5%, and 5.25% sodium hypochlorite (NaOCl). The solutions were used for 5, 15, and 30 minutes and at 2 experimental volumes, 500 μL and 1 mL. The samples were stained by using acridine orange dye before and after the experiments and evaluated by using a confocal microscope. The percentage of biofilm, isolated cells, and noncolonized dentin was measured by using a grid system. Differences in the reduction or increase of the studied parameters were assessed by using nonparametric methods (P < .05).
  
  
  RESULTS
  The higher values of biofilm dissolution and noncolonized dentin were found in the 30-minute NaOCl group and in the 5-minute and 15-minute groups of 5.25% NaOCL. The use of 2% chlorhexidine solution did not improve the biofilm dissolution or increase the cleaning of the dentin in comparison with the NaOCl solutions (P < .05).
  
  
  CONCLUSIONS
  Two percent chlorhexidine does not dissolve the biofilms. Thirty minutes of NaOCl are necessary to have higher values of biofilm dissolution and to increase the cleaning of the dentin independently of the concentration in comparison with the 5-minute and 15-minute contact times.
authors.affiliation: Department of Endodontics, Bauru Dental School of Bauru, University of São Paulo, Bauru, São Paulo, Brazil.
authors.forename: Aldo E
authors.initials: AE
authors.lastname: Del Carpio-Perochena
authors.forename: Clovis M
authors.initials: CM
authors.lastname: Bramante
authors.forename: Marco A H
authors.initials: MA
authors.lastname: Duarte
authors.forename: Bruno Cavalini
authors.initials: BC
authors.lastname: Cavenago
authors.forename: Marcelo H
authors.initials: MH
authors.lastname: Villas-Boas
authors.forename: Marcia S
authors.initials: MS
authors.lastname: Graeff
authors.forename: Norberti
authors.initials: N
authors.lastname: Bernardineli
authors.forename: Flaviana Bombarda
authors.initials: FB
authors.lastname: de Andrade
authors.forename: Ronald
authors.initials: R
authors.lastname: Ordinola-Zapata
mesh_terms: D000818:Animals; D018441:Biofilms / Q000187:drug effects*; D002417:Cattle; D002710:Chlorhexidine / Q000008:administration & dosage; D003804:Dentin / Q000382:microbiology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D018613:Microscopy, Confocal; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D018915:Root Canal Preparation / Q000379:methods; D012973:Sodium Hypochlorite / Q000008:administration & dosage; D018709:Statistics, Nonparametric; D007507:Therapeutic Irrigation; D013997:Time Factors
chemical_list: D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite; D002710:Chlorhexidine