title: Response of E. faecalis biofilms to different associations of auxiliary substances during root canal preparation: a confocal laser microscopy analysis.
abstract: OBJECTIVE
  This in vitro study evaluated the effect of different endodontic auxiliary chemical substances over Enterococcus faecalis (Ef) biofilm through confocal laser scanning microscopy (CLSM).
  
  
  METHODS
  Forty-five bovine incisors were infected with Ef for 21 days. Teeth were divided into five groups: group 1: 2.5% NaOCl + EDTA, group 2: 2% CHX gel + EDTA, group 3: 2% CHX liquid + EDTA, group 4: 2.5% NaOCl + 2% CHX gel + EDTA, group 5: 2.5% NaOCl + 2% CHX liquid + EDTA and a negative and a positive control group (NCG; PCG). The samples were stained with SYTO9 and propidium iodide and analyzed by CLSM. Bacterial viability was quantitatively analyzed by the proportions of dead and live bacteria in the biofilm remnants. Scores were standardized according to the total bacterial load (TBL)-1: ≤ 25%, 2: >25 ≤ 50%, 3: >50 ≤ 75%, 4: >75% and debris-1: absence of debris; 2: presence of debris. Statistical analysis was carried out through the Kruskal-Wallis and the Fischer exact tests (P = 0.05).
  
  
  RESULTS
  No statistical differences were observed to CFU, debris and bacterial viability.
  
  
  CONCLUSIONS
  None of the tested substances could completely eliminate Ef from the root canal space.
authors.affiliation: Conservative Dentistry Department, School of Dentistry, Federal University of Rio Grande do Sul (UFRGS), Av. Ramiro Barcelos, 2492, Porto Alegre/RS, Cep 90035-003, Brazil.
authors.forename: Gabriela Luisa
authors.initials: GL
authors.lastname: Hohscheidt
authors.forename: Daiana Elisabeth
authors.initials: DE
authors.lastname: Böttcher
authors.forename: Clarissa Cavalcanti
authors.initials: CC
authors.lastname: Fatturi Parolo
authors.forename: Francisco
authors.initials: F
authors.lastname: Montagner
authors.forename: Fabiana Soares
authors.initials: FS
authors.lastname: Grecca
mesh_terms: D000818:Animals; D018441:Biofilms / Q000187:drug effects*; D002417:Cattle; D015169:Colony Count, Microbial; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000502:physiology*; D066298:In Vitro Techniques; D007180:Incisor / Q000382:microbiology*; D007287:Inorganic Chemicals / Q000627:therapeutic use*; D050296:Microbial Viability / Q000187:drug effects; D018613:Microscopy, Confocal; D018915:Root Canal Preparation; D013194:Staining and Labeling
chemical_list: D007287:Inorganic Chemicals