title: Short-term antibacterial activity of root canal sealers towards Enterococcus faecalis.
abstract: OBJECTIVE
  To investigate the antimicrobial activity of root canal sealers on Enterococcus faecalis, either allowing or avoiding direct contact between sealers and bacteria.
  
  
  METHODS
  Filter paper discs were immersed in standardized E. faecalis suspensions and exposed to freshly mixed sealers (MCS, AH Plus, Grossman's sealer, Sealapex, Apexit) in teflon wells for 30 min, with or without a filter membrane placed between filter paper discs and sealers (membrane-restricted contact test and direct contact test, respectively). After exposure, the filter paper discs were transferred to vials containing phosphate-buffered saline (PBS) and glass beads, and vigorously vortexed. PBS with resuspended bacterial cells was serially diluted and 25 microL droplets were seeded on TSA plates. The plates were incubated in air at 37 degrees C for 24 h and colony-forming units were counted. Using alpha = 0.05 as level for statistical significance, the data obtained were analysed using Student's t-test.
  
  
  RESULTS
  In the direct contact test, MCS and AH Plus killed the bacteria to a level below the detection limit. They were followed in decreasing order of efficacy by Grossman's sealer, Sealapex and Apexit. In the membrane-restricted contact test, the sealers ranked: MCS, AH Plus, Grossman's sealer, Apexit and Sealapex, in descending order of antibacterial potency. MCS, AH Plus and Grossman's sealer significantly reduced the number of viable bacteria in both tests. Sealapex and Apexit were not statistically different from control.
  
  
  CONCLUSIONS
  MCS, AH Plus and Grossman's sealer were effective in reducing the number of cultivable cells of E. faecalis. Calcium hydroxide-based sealers, Sealapex and Apexit were ineffective in this short-term experiment.
authors.affiliation: Department of Endodontics and Conservative Treatment, Faculty of Dentistry, Gazi University, Ankara, Turkey. guvenk@gazi.edu.tr
authors.forename: G
authors.initials: G
authors.lastname: Kayaoglu
authors.forename: H
authors.initials: H
authors.lastname: Erten
authors.forename: T
authors.initials: T
authors.lastname: Alaçam
authors.forename: D
authors.initials: D
authors.lastname: Ørstavik
mesh_terms: D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D002126:Calcium Hydroxide / Q000494:pharmacology; D015169:Colony Count, Microbial; D003786:Dental Pulp Cavity / Q000382:microbiology; D013293:Enterococcus faecalis / Q000187:drug effects*; D004853:Epoxy Resins / Q000494:pharmacology; D006847:Hydrocarbons, Iodinated / Q000494:pharmacology; D012387:Root Canal Filling Materials / Q000494:pharmacology*; D012459:Salicylates / Q000494:pharmacology; D015035:Zinc Oxide-Eugenol Cement / Q000494:pharmacology
chemical_list: D000891:Anti-Infective Agents, Local; C074418:Apexit; D004853:Epoxy Resins; D006847:Hydrocarbons, Iodinated; C502330:MCS Canal Sealer; D012387:Root Canal Filling Materials; D012459:Salicylates; D015035:Zinc Oxide-Eugenol Cement; C534916:epoxy resin-based root canal sealer; C045432:Grossman's sealer; C055601:Sealapex; C010473:iodoform; D002126:Calcium Hydroxide