title: Antibacterial effect of composite resin foundation material incorporating quaternary ammonium polyethyleneimine nanoparticles.
abstract: BACKGROUND
  As caries is the most frequent cause of the failure of composite resin-based restorations, composite resins with antibacterial properties are desirable. However, whether quaternary ammonium polyethyleneimine nanoparticles can be effectively incorporated is unknown.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to evaluate the antibacterial activity against Streptococcus mutans and Actinomyces viscosus of a foundation material incorporating quaternary ammonium polyethyleneimine (QPEI) nanoparticles.
  
  
  METHODS
  QPEI antimicrobial nanoparticles were incorporated in a commercially available foundation material (Q Core; BJM Laboratories Ltd) at 1% wt/wt. Antibacterial efficacy against S mutans (106colony-forming units [CFU]/mL) and A viscosus (106CFU/mL) was examined by the direct contact test (DCT), and the agar diffusion test (ADT) with and without surface polishing. Bacterial outgrowth was recorded with a spectrophotometer.
  
  
  RESULTS
  Growth of S mutans and A viscosus was inhibited, showing a decrease by 6 orders of magnitude in bacterial viability in specimens incorporating the nanoparticles, even after polishing the foundation material (P<.05). Growth inhibition was not observed in specimens without nanoparticles.
  
  
  CONCLUSIONS
  Antibacterial properties can be achieved in a commercially available foundation material by incorporating polycationic antibacterial nanoparticles. This antibacterial effect did not diminish after surface polishing.
authors.affiliation: Clinical Instructor, Department of Prosthodontics, The Hebrew University, Hadassah Faculty of Dental Medicine, Jerusalem, Israel. Electronic address: yoavpi@gmail.com.
authors.forename: Yoav
authors.initials: Y
authors.lastname: Pietrokovski
authors.affiliation: Graduate student, Department of Prosthodontics, The Hebrew University, Hadassah Faculty of Dental Medicine, Jerusalem, Israel.
authors.forename: Ilana
authors.initials: I
authors.lastname: Nisimov
authors.affiliation: Graduate student, Department of Prosthodontics, The Hebrew University, Hadassah Faculty of Dental Medicine, Jerusalem, Israel.
authors.forename: Dana
authors.initials: D
authors.lastname: Kesler-Shvero
authors.affiliation: Graduate student, Department of Prosthodontics, The Hebrew University, Hadassah Faculty of Dental Medicine, Jerusalem, Israel.
authors.forename: Natan
authors.initials: N
authors.lastname: Zaltsman
authors.affiliation: Associate Professor, Department of Prosthodontics, The Hebrew University, Hadassah Faculty of Dental Medicine, Jerusalem, Israel.
authors.forename: Nurit
authors.initials: N
authors.lastname: Beyth
mesh_terms: D016924:Actinomyces viscosus / Q000187:drug effects; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003188:Composite Resins / Q000494:pharmacology*; D052978:Disk Diffusion Antimicrobial Tests; D066298:In Vitro Techniques; D053758:Nanoparticles; D011094:Polyethyleneimine / Q000494:pharmacology*; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*; D013295:Streptococcus mutans / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D003188:Composite Resins; D000644:Quaternary Ammonium Compounds; D011094:Polyethyleneimine