title: Preparation and characterization of ZnO-PMMA resin nanocomposites for denture bases.
abstract: OBJECTIVE
  The aim of the paper was to investigate the antifungal activity of zinc oxide nanoparticles (ZnONPs) against Candida albicans. Some attempts have been made to find out the best way to introduce ZnONPs into polymethyl methacrylate (PMMA) resin material and to determine some parameters of a newly formed composite.
  
  
  METHODS
  Zinc oxide nanoparticles were manufactured and their basic physical parameters were determined (average particle size, density, specific surface area). Minimal inhibitory concentration (MIC) of ZnONPs was determined for the Candida albicans standard strain. The average size of ZnO conglomerates in the monomer solution of PMMA resin was measured using a dynamic light scattering instrument. PMMA resin samples with incorporated ZnONPs were produced. The morphology of nanopowder and the newly formed composite was examined under a scanning electron microscope (SEM). In addition, the roughness parameter of PMMA resin material was investigated before and after ZnONPs modification.
  
  
  RESULTS
  Nanopowder with the average particle size of 30 nm, density of 5.24 g/cm3 and surface area of 39 m2/g was obtained. MIC was determined at the level of 0.75 mg/mL. The average size of ZnO conglomerates in the monomer solution of acrylic resin dropped by 11 times after ultrasound activation. SEM examination of a newly formed composite showed a successful introduction of ZnONPs confirmed by the energy dispersive X-ray spectroscopy (EDS) analysis. There were no statistically significant differences in the biomaterial roughness before and after the modification of ZnONPs.
  
  
  CONCLUSIONS
  Zinc oxide nanoparticles were successfully incorporated into acrylic resin used for the production of denture bases. The presence of nanoparticles with sizes below 100 nm was confirmed. Nevertheless a newly created composite needs to be further investigated to improve its homogeneity, and to check its microbiological properties, strength and biocompatibility prior to its possible clinical use.
authors.affiliation: Department of Prosthetic Dentistry, Medical University of Warsaw, Poland.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Cierech
authors.affiliation: Institute of High Pressure Physic, Polish Academy of Sciences, Warsaw, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Wojnarowicz
authors.affiliation: Division of Silicon Microsystem and Nanostructure Technology, Institute of Electron Technology, Warsaw, Poland.
authors.forename: Dariusz
authors.initials: D
authors.lastname: Szmigiel
authors.affiliation: Department of Prosthetic Dentistry, Medical University of Warsaw, Poland.
authors.forename: Bohdan
authors.initials: B
authors.lastname: Bączkowski
authors.affiliation: Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, University of Warsaw, Poland.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Grudniak
authors.affiliation: Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, University of Warsaw, Poland.
authors.forename: Krystyna Izabela
authors.initials: KI
authors.lastname: Wolska
authors.affiliation: Institute of High Pressure Physic, Polish Academy of Sciences, Warsaw, Poland.|Faculty of Management, Białystok University of Technology, Białystok, Poland.
authors.forename: Witold
authors.initials: W
authors.lastname: Łojkowski
authors.affiliation: Department of Prosthetic Dentistry, Medical University of Warsaw, Poland.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Mierzwińska-Nastalska
mesh_terms: D000180:Acrylic Resins / Q000138:chemical synthesis*; D002176:Candida albicans / Q000187:drug effects; D003460:Crystallization; D003819:Denture Bases; D008422:Materials Testing; D008872:Microwaves; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D019904:Polymethyl Methacrylate / Q000138:chemical synthesis* / Q000494:pharmacology; D012117:Resins, Synthetic / Q000138:chemical synthesis* / Q000494:pharmacology; D013010:Sonication; D013052:Spectrometry, X-Ray Emission; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000138:chemical synthesis* / Q000494:pharmacology
chemical_list: D000180:Acrylic Resins; D012117:Resins, Synthetic; D019904:Polymethyl Methacrylate; D015034:Zinc Oxide