title: Confocal microscopy evaluation of the effect of irrigants on Enterococcus faecalis biofilm: An in vitro study.
abstract: The purpose of this study was to evaluate in vitro the effectiveness of two endodontic irrigants and their association against Enterococcus faecalis (E. faecalis) by confocal laser scanning microscope (CLSM). Twenty-four bovine incisors were inoculated in a monoculture of E. faecalis for 21 days. After this period, the teeth were divided into three test groups (n = 5) according to the chemical used. Group 1: 2.5% sodium hypochlorite (NaOCl), group 2: 2% chlorhexidine gel (CHX), group 3: 2.5% NaOCl + 2% CHX gel, and two control groups (n = 3): negative control group (NCG)-sterile and without root canals preparation and positive control group (PCG)-saline. Then, the samples were stained with SYTO9 and propidium iodide and subjected to analysis by CLSM. Bacterial viability was quantitatively analyzed by the proportions of dead and live bacteria in the biofilm remnants. Statistical analysis was performed by the One-way ANOVA test (p = 0.05). No statistical differences were observed to bacterial viability. According to CLSM analysis, none of the tested substances could completely eliminate E. faecalis from the root canal space. Until now, there are no irrigant solutions able to completely eliminate E. faecalis from the root canal. In this regard, the search for irrigants able to intensify the antimicrobial action is of paramount importance.
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul, Brazil.
authors.forename: Nicole
authors.initials: N
authors.lastname: Flach
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul, Brazil.
authors.forename: Daiana Elisabeth
authors.initials: DE
authors.lastname: Böttcher
authors.affiliation: Department of Preventive and Social Dentistry, School of Dentistry, Federal University of Rio Grande do Sul, Brazil.
authors.forename: Clarissa Cavalcanti Fatturi
authors.initials: CC
authors.lastname: Parolo
authors.affiliation: Department of Preventive and Social Dentistry, School of Dentistry, Federal University of Rio Grande do Sul, Brazil.
authors.forename: Luciana Bitello
authors.initials: LB
authors.lastname: Firmino
authors.affiliation: Department of Preventive and Social Dentistry, School of Dentistry, Federal University of Rio Grande do Sul, Brazil.
authors.forename: Marisa
authors.initials: M
authors.lastname: Malt
authors.affiliation: Morphological Sciences Department, Basic Health Institute, Federal University of Rio Grande do Sul, Brazil.
authors.forename: Marcelo Lazzaron
authors.initials: ML
authors.lastname: Lammers
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul, Brazil.
authors.forename: Fabiana Soares
authors.initials: FS
authors.lastname: Grecca
mesh_terms: D000818:Animals; D018441:Biofilms / Q000187:drug effects*; D002417:Cattle; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000502:physiology*; D007180:Incisor / Q000382:microbiology*; D050296:Microbial Viability / Q000187:drug effects; D018613:Microscopy, Confocal; D009930:Organic Chemicals; D011419:Propidium; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D013194:Staining and Labeling
chemical_list: D009930:Organic Chemicals; D012388:Root Canal Irrigants; C103389:SYTO 9; D011419:Propidium
keywords: Enterococcus faecalis; chlorhexidine; confocal laser scanning microscopy; endodontics; laboratory research; root canal preparation; sodium hypochlorite