title: Influence of silver nano-particles on monomer elution from light-cured composites.
abstract: OBJECTIVE
  Silver containing materials have been used for years as antimicrobial materials. Silver particles were also added to experimental dental composites to reduce caries. The aim of our study was to show whether silver nanoparticles can lead to higher amounts of elutable substances.
  
  
  METHODS
  0.0125, 0.025, 0.05, 0.1 and 0.3% by weight silver nanoparticles were added to the commercial composite Tetric Flow®. After light curing of the specimen, they were stored up to 7 days in methanol. The eluate was analyzed by gas chromatography/mass spectrometry.
  
  
  RESULTS
  Compared to controls more camphorquinone (CQ), ethoxylated bisphenol-A-dimethacrylate (BisEMA) and triethylene glycol dimethacrylate (TEGDMA) will be eluted when silver nanoparticles were added to the composite. Twenty-four hours after the beginning of the experiment 132μmol/l of CQ, 33.9μmol/l BisEMA and 4.5mmol/l TEGDMA were found in the eluate of the specimens containing 0.3% Ag.
  
  
  CONCLUSIONS
  Silver nanoparticles may influence the polymerization process in dental materials and lead to an increase in elutable substances. Four possible mechanisms of interaction are discussed: (1) reflection and scattering of the photons, (2) absorption of photons, (3) electron transfer from or to the silver nanoparticles and (4) formation of complexes with Ag(+)-ions.
authors.affiliation: Walther-Straub-Institute of Pharmacology und Toxicology, Nussbaumstr. 26, 80336 Munich, Germany. juergen.durner@med.uni-muenchen.de
authors.forename: Jürgen
authors.initials: J
authors.lastname: Durner
authors.forename: Marija
authors.initials: M
authors.lastname: Stojanovic
authors.forename: Ebru
authors.initials: E
authors.lastname: Urcan
authors.forename: Reinhard
authors.initials: R
authors.lastname: Hickel
authors.forename: Franx-Xaver
authors.initials: FX
authors.lastname: Reichl
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D056831:Coordination Complexes; D004579:Electron Transport; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D008689:Methacrylates / Q000032:analysis; D053758:Nanoparticles / Q000737:chemistry; D017785:Photons; D011092:Polyethylene Glycols / Q000032:analysis; D058105:Polymerization; D011109:Polymethacrylic Acids / Q000032:analysis; D012542:Scattering, Radiation; D012834:Silver / Q000737:chemistry*; D018030:Silver Compounds; D013729:Terpenes / Q000032:analysis
chemical_list: D000900:Anti-Bacterial Agents; D003188:Composite Resins; D056831:Coordination Complexes; D008689:Methacrylates; D011109:Polymethacrylic Acids; D018030:Silver Compounds; D013729:Terpenes; C452226:tetric flow composite resin; C020946:triethylene glycol dimethacrylate; D012834:Silver; D011092:Polyethylene Glycols; C074277:ethoxylated bis-phenol A dimethacrylate; C048339:camphoroquinone