title: Antibiofilm activity of irrigating solutions associated with cetrimide. Confocal laser scanning microscopy.
abstract: OBJECTIVE
  To evaluate the antibiofilm activity of sodium hypochlorite (NaOCl) and chlorhexidine (CHX) solutions associated with cetrimide (CTR), and QMiX using confocal laser scanning microscopy.
  
  
  METHODS
  Enterococcus faecalis (ATCC- 29212) biofilms were induced on bovine dentine blocks for 14 days. The dentine blocks containing biofilm were immersed for 1 min in the following solutions: 2.5% NaOCl; 2.5% NaOCl + 0.2% CTR; 2% CHX; 2% CHX + 0.2% CTR; 0.2% CTR; QMiX. After contact with the solutions, the dentine blocks were stained with Live/Dead(®) BacLight for analysis of the remaining biofilm using confocal laser scanning microscope. Images were evaluated using the BioImage_L software to determine the total biovolume (μm(3) ), the green biovolume (live cells) (μm(3) ) and the percentage of substrate coverage (%). The data were subjected to nonparametric statistical test using Kruskal-Wallis and Dunn's tests at 5% significance level.
  
  
  RESULTS
  After exposure to irrigants, the total biovolume observed for CHX, CHX+CTR, CTR, QMiX was similar to distilled water (P > 0.05). NaOCl and NaOCl+CTR had the lowest total and green biovolume. The CTR and QMiX had intermediate green biovolume, with greater antibacterial activity than CHX and CHX+CTR (P < 0.05). The NaOCl and NaOCl+CTR solutions were associated with microorganism removal and substrate cleaning ability.
  
  
  CONCLUSIONS
  NaOCl and NaOCl+CTR solutions were effective on microorganism viability and were able to eliminate biofilm. The addition of cetrimide did not influence antibacterial activity.
authors.affiliation: Department of Restorative Dentistry, Araraquara Dental School, UNESP (Univ Estadual Paulista), Araraquara, SP, Brazil.
authors.forename: J M
authors.initials: JM
authors.lastname: Guerreiro-Tanomaru
authors.forename: C A
authors.initials: CA
authors.lastname: Nascimento
authors.forename: N B
authors.initials: NB
authors.lastname: Faria-Júnior
authors.forename: M S Z
authors.initials: MS
authors.lastname: Graeff
authors.forename: E
authors.initials: E
authors.lastname: Watanabe
authors.forename: M
authors.initials: M
authors.lastname: Tanomaru-Filho
mesh_terms: D000818:Animals; D018441:Biofilms; D002417:Cattle; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry*; D018613:Microscopy, Confocal; D007507:Therapeutic Irrigation
chemical_list: D002593:Cetrimonium Compounds; D000077286:Cetrimonium
keywords: Enterococcus faecalis; biofilm; chlorhexidine; confocal laser scanning microscopy; sodium hypochlorite