title: Residual and antimicrobial activity of final irrigation protocols on Enterococcus faecalis biofilm in dentin.
abstract: BACKGROUND
  The use of root canal irrigating solutions exerting antimicrobial activity and prolonged residual activity is desirable in order to control dentin infection and delay reinfection of the root canal. The aim of this study was to evaluate the residual antimicrobial activity and the capacity to eradicate Enterococcus faecalis biofilm of different irrigating solutions, alone and in combination, in a dentin-volumetric test.
  
  
  METHODS
  Solutions of 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), 0.2% cetrimide (CTR), 17% ethylendiaminetetraacetic (EDTA), 7% maleic acid (MA), and regimens of 2.5% NaOCl followed by 17% EDTA or 7% MA and 0.2% CTR or 2% CHX were used to determine their residual activity by exposing treated dentin blocks to E. faecalis for 24 hours. Antimicrobial activity was assayed on 3-week biofilm formed on dentin blocks. Results of residual activity and antimicrobial activity were respectively expressed as the inhibition percentage of biofilm formation and the kill percentage of biofilm.
  
  
  RESULTS
  A 2% CHX and 0.2% CTR solution showed 100% biofilm inhibition; 2.5% NaOCl showed the lowest residual activity (18.10%). The kill percentage of 2.5% NaOCl and 0.2% CTR was 100% followed by 7% MA and 2% CHX, whereas 17% EDTA was the least effective (44%). Solutions of 7% MA or 17% EDTA followed by 0.2% CTR or 2% CHX showed 100% residual and antimicrobial activity.
  
  
  CONCLUSIONS
  A 0.2% CTR solution alone and the combinations in which 2% CHX or 0.2% CTR was the final irrigating solution achieved the maximum residual and antimicrobial activity.
authors.affiliation: Department of Preventive and Operative Dentistry, School of Dentistry, University of Granada, Granada, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Baca
authors.forename: Pilar
authors.initials: P
authors.lastname: Junco
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Arias-Moliz
authors.forename: María Paloma
authors.initials: MP
authors.lastname: González-Rodríguez
authors.forename: Carmen María
authors.initials: CM
authors.lastname: Ferrer-Luque
mesh_terms: D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects*; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000008:administration & dosage / Q000494:pharmacology; D002614:Chelating Agents / Q000008:administration & dosage / Q000494:pharmacology; D002710:Chlorhexidine / Q000008:administration & dosage / Q000494:pharmacology; D003804:Dentin / Q000382:microbiology*; D004338:Drug Combinations; D004492:Edetic Acid / Q000008:administration & dosage / Q000494:pharmacology; D013293:Enterococcus faecalis / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D006801:Humans; D006813:Humidity; D008298:Maleates / Q000008:administration & dosage / Q000494:pharmacology; D008422:Materials Testing; D050296:Microbial Viability / Q000187:drug effects; D012388:Root Canal Irrigants / Q000494:pharmacology*; D018915:Root Canal Preparation / Q000379:methods*; D012973:Sodium Hypochlorite / Q000008:administration & dosage / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors
chemical_list: D000890:Anti-Infective Agents; D000891:Anti-Infective Agents, Local; D002593:Cetrimonium Compounds; D002614:Chelating Agents; D004338:Drug Combinations; D004791:Enzyme Inhibitors; D008298:Maleates; D012388:Root Canal Irrigants; C030272:maleic acid; D004492:Edetic Acid; D012973:Sodium Hypochlorite; D002710:Chlorhexidine; D000077286:Cetrimonium