title: Antimicrobial activity of root canal irrigants associated with cetrimide against biofilm and planktonic Enterococcus faecalis.
abstract: OBJECTIVE
  To evaluate the antibacterial activity of sodium hypochlorite (NaOCl) and chlorhexidine (CHX) alone or associated with cetrimide (CTR), and QMiX against biofilm and planktonic Enterococcus faecalis (E. faecalis) [American type culture collection (ATCC) 29212].
  
  
  METHODS
  The solutions 2.5% NaOCl, 2.5% NaOCl + 0.2% CTR, 2% CHX, 2% CHX + 0.2% CTR, 0.2% CTR, and QMiX were evaluated. E. faecalis biofilms were induced for 14 days on bovine dentin blocks. The irrigants were evaluated after contact with E. faecalis suspension and biofilm for 1 and 3 minutes. After that, serial decimal dilutions were made and plated on tryptic soy agar (TSA) medium. Plates were incubated for 24 hours at 37°C and the colony-forming unit (CFU) 1 ml was determined. Data were subjected to ANOVA and Tukey's tests at 5% significance.
  
  
  RESULTS
  All microorganisms were eliminated by direct contact of the irrigants with planktonic cells. Only NaOCl and NaOCl + CTR were able to completely eliminate the microorganisms by direct contact with E. faecalis biofilm. CHX presented effectiveness similar to CHX + CTR CTR, and QMiX after 1 minute of contact and similar to NaOCl and NaOCl + CTR after 3 minutes (p > 0.05), but was unable to completely eliminate the microorganisms. CTR and QMiX did not differ from each other.
  
  
  CONCLUSIONS
  CTR addition to CHX and NaOCl solutions did not improve the antimicrobial activity against biofilm. All evaluated irrigants and associations presented activity against planktonic E. faecalis. Only NaOCl and NaOCl + CTR eliminated biofilm after 1 and 3 minutes of direct contact.
authors.affiliation: MSc Student, Department of Restorative Dentistry, Araraquara Dental School, São Paulo State University (UNESP), Araraquara São Paulo, Brazil.
authors.forename: Camila Almeida
authors.initials: CA
authors.lastname: Nascimento
authors.affiliation: Professor, Department of Restorative Dentistry, Araraquara Dental School, São Paulo State University (UNESP), Araraquara São Paulo, Brazil, e-mail: tanomaru@uol.com.br.
authors.forename: Mario
authors.initials: M
authors.lastname: Tanomaru-Filho
authors.affiliation: PhD Student, Department of Restorative Dentistry, Araraquara Dental School, São Paulo State University (UNESP), Araraquara São Paulo, Brazil.
authors.forename: Norberto Batista
authors.initials: NB
authors.lastname: Faria-Junior
authors.affiliation: Professor, Department of Restorative Dentistry, Araraquara Dental School, São Paulo State University (UNESP), Araraquara São Paulo, Brazil.
authors.forename: Gisele
authors.initials: G
authors.lastname: Faria
authors.affiliation: Professor, Department of Restorative Dentistry, Araraquara Dental School, São Paulo State University (UNESP), Araraquara São Paulo, Brazil.
authors.forename: Juliane Maria
authors.initials: JM
authors.lastname: Guerreiro-Tanomaru
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000494:pharmacology; D058491:Bacterial Load / Q000187:drug effects; D001645:Biguanides / Q000008:administration & dosage / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects*; D002417:Cattle; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000008:administration & dosage / Q000494:pharmacology*; D002710:Chlorhexidine / Q000008:administration & dosage / Q000494:pharmacology; D003804:Dentin / Q000382:microbiology; D004338:Drug Combinations; D013293:Enterococcus faecalis / Q000187:drug effects*; D008422:Materials Testing; D011108:Polymers / Q000008:administration & dosage / Q000494:pharmacology; D012388:Root Canal Irrigants / Q000008:administration & dosage / Q000494:pharmacology*; D012973:Sodium Hypochlorite / Q000008:administration & dosage / Q000494:pharmacology; D013501:Surface-Active Agents / Q000008:administration & dosage / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D000891:Anti-Infective Agents, Local; D001645:Biguanides; D002593:Cetrimonium Compounds; D004338:Drug Combinations; D011108:Polymers; C557698:QMix root canal irrigant; D012388:Root Canal Irrigants; D013501:Surface-Active Agents; D012973:Sodium Hypochlorite; D002710:Chlorhexidine; D000077286:Cetrimonium