title: Morphology and electrochemical behavior of Ag-Cu nanoparticle-doped amalgams.
abstract: The aim of this study was to introduce Ag-Cu phase nanopowder as an additive to improve the corrosion behavior of dental amalgams. A novel Ag-Cu nanopowder was synthesized by the precipitation method. An amalgam alloy powder (World-Cap) was added and mixed with 5 wt.% and 10 wt.% of Ag-Cu nanopowders, respectively, to form experimental amalgam alloy powders. The original alloy powder was used as a control. Alloy powders were examined using X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy and electron probe microanalysis. Amalgam disk specimens of metallurgically prepared were tested in 0.9% NaCl solution using electrochemical methods. The changes in the corrosion potential and anodic polarization characteristics were determined. Corrosion potential data were analyzed statistically (n=3, analysis of variance, Tukey's test, p<0.05). The diameters of lamellar structure Ag-Cu nanoparticles were measured to be approximately 30 nm. The composition of the Ag-Cu nanoparticles determined by TEM-energy-dispersive spectroscopy was 56.28 at.% Ag-43.72 at.% Cu. A light-shaded phase was found mixing with dark Cu-Sn reaction particles in the reaction zones of Ag-Cu nanoparticle-doped amalgams. The Ag-Cu nanoparticle-doped amalgams exhibited zero current potentials more positive than the control (p<0.05) and no current peak was observed at -325mV that related to Ag-Hg phase and Cu6Sn5 phase in anodic polarization curves. The results indicated that the corrosion resistance of high-copper single-composition amalgam could be improved by Ag-Cu nanoparticle-doping.
authors.affiliation: Division of Dental Materials Science, Department of Restorative Dentistry, University of Washington, Seattle, WA, USA.
authors.forename: Kwok-Hung
authors.initials: KH
authors.lastname: Chung
authors.forename: Li-Yin
authors.initials: LY
authors.lastname: Hsiao
authors.forename: Yu-Sheng
authors.initials: YS
authors.lastname: Lin
authors.forename: Jenq-Gong
authors.initials: JG
authors.lastname: Duh
mesh_terms: D003300:Copper / Q000737:chemistry*; D003723:Dental Amalgam / Q000737:chemistry*; D004563:Electrochemistry; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011199:Potentiometry; D012834:Silver / Q000737:chemistry*; D012996:Solutions; D014961:X-Ray Diffraction
chemical_list: D012996:Solutions; D012834:Silver; D003300:Copper; D003723:Dental Amalgam