title: Antibiofilm effects of endodontic sealers containing quaternary ammonium polyethylenimine nanoparticles.
abstract: BACKGROUND
  This study evaluated the antibiofilm effects of 2 endodontic sealers incorporated with quaternary ammonium polyethylenimine (QPEI) nanoparticles at a 2% concentration (w/w).
  
  
  METHODS
  The materials tested were AH Plus and Pulp Canal Sealer EWT (PCS) in the commercial unmodified form or containing 2% QPEI. Antibiofilm assays were conducted by using direct-contact and membrane-restricted tests for evaluation of bacterial viability in biofilms grown onto membranes or paper disks and the crystal violet microtiter-plate assay to evaluate the effects of sealer extracts on the biofilm biomass. Two Enterococcus faecalis strains (ATCC and an endodontic isolate) were used.
  
  
  RESULTS
  Direct contact and membrane-restricted antibiofilm tests revealed that PCS 2% was the only material to promote total killing of E. faecalis ATCC biofilms. All the materials significantly reduced bacterial counts in E. faecalis ATCC biofilms when compared with the positive control in both tests (P < .05). In the direct test against E. faecalis RW35, PCS 2% was significantly more effective than the other materials and was the only one that showed significantly lower counts than the positive control (P < .05). In the crystal violet assay, only AH Plus 2% presented optical density readings significantly lower than the positive control of the ATCC strain (P < .05). No other significant effects on the biofilm biomass of the 2 E. faecalis strains were observed for any of the sealers tested (P > .05).
  
  
  CONCLUSIONS
  Addition of QPEI nanoparticles improved the killing ability of PCS against biofilms of both E. faecalis strains and the effects of AH Plus on the biomass of biofilms from the ATCC strain.
authors: Department of Endodontics, Faculty of Dentistry, University of Porto, Porto, Portugal. Electronic address: joana.barros.c@gmail.com.
authors: Joana
authors: J
authors: Barros
authors: Department of Endodontics, Faculty of Dentistry, Estácio de Sá University, Rio de Janeiro, Rio de Janeiro, Brazil.
authors: Marlei G
authors: MG
authors: Silva
authors: Department of Endodontics, Faculty of Dentistry, Estácio de Sá University, Rio de Janeiro, Rio de Janeiro, Brazil.
authors: Isabela N
authors: IN
authors: Rôças
authors: Department of Endodontics, Faculty of Dentistry, Estácio de Sá University, Rio de Janeiro, Rio de Janeiro, Brazil.
authors: Lucio S
authors: LS
authors: Gonçalves
authors: Department of Endodontics, Faculty of Dentistry, Estácio de Sá University, Rio de Janeiro, Rio de Janeiro, Brazil.
authors: Flávio F
authors: FF
authors: Alves
authors: CEMUC, Department of Metallurgical and Materials Engineering, Faculty of Engineering, University of Porto, Porto, Portugal.
authors: Maria A
authors: MA
authors: Lopes
authors: Department of Endodontics, Faculty of Dentistry, University of Porto, Porto, Portugal.
authors: Irene
authors: I
authors: Pina-Vaz
authors: Department of Endodontics, Faculty of Dentistry, Estácio de Sá University, Rio de Janeiro, Rio de Janeiro, Brazil.
authors: José F
authors: JF
authors: Siqueira
mesh_terms: D058491:Bacterial Load / Q000187:drug effects; D001431:Bacteriological Techniques / Q000295:instrumentation; D018441:Biofilms / Q000187:drug effects*; D018533:Biomass; D003786:Dental Pulp Cavity / Q000382:microbiology; D013293:Enterococcus faecalis / Q000187:drug effects; D004853:Epoxy Resins / Q000494:pharmacology; D005374:Filtration / Q000295:instrumentation; D005840:Gentian Violet; D006801:Humans; D008422:Materials Testing; D050296:Microbial Viability / Q000187:drug effects; D053758:Nanoparticles / Q000737:chemistry*; D011094:Polyethyleneimine / Q000494:pharmacology*; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*; D012387:Root Canal Filling Materials / Q000494:pharmacology*; D015035:Zinc Oxide-Eugenol Cement / Q000494:pharmacology
chemical_list: D004853:Epoxy Resins; D000644:Quaternary Ammonium Compounds; D012387:Root Canal Filling Materials; D015035:Zinc Oxide-Eugenol Cement; C534916:epoxy resin-based root canal sealer; C076543:Kerr Pulp Canal Sealer; D011094:Polyethyleneimine; D005840:Gentian Violet
keywords: Biofilms; Enterococcus faecalis; endodontic sealers; nanoparticles; quaternary ammonium