Media type: E-Article Title: Corrosion of dental nickel–aluminum bronze with a minor gold content‐mechanism and biological impact Contributor: Ardlin, Berit I.; Lindholm‐Sethson, Britta; Dahl, Jon E. imprint: Wiley, 2009 Published in: Journal of Biomedical Materials Research Part B: Applied Biomaterials Language: English DOI: 10.1002/jbm.b.31143 ISSN: 1552-4973; 1552-4981 Keywords: Biomedical Engineering ; Biomaterials Origination: Footnote: Description: <jats:title>Abstract</jats:title><jats:p><jats:italic>Objectives:</jats:italic> To study corrosion and to evaluate biological effects <jats:italic>in vitro</jats:italic> of corrosion products of a copper‐aluminum‐nickel alloy with 2% gold. <jats:italic>Methods:</jats:italic> The alloy NPG™+2 with the nominal composition Cu:77.3; Al:7.8; Ni:4.3; Fe:3.0; Zn:2.7; Au:2.0; and Mn:1.7 was characterized. Static immersion in acidic saline, pH 2.2–2.4, was used to determine release of metallic elements in a milieu simulating the condition of plaque build‐up in interproximal areas of the tooth. Corrosion and surface reactions in saline and artificial saliva were studied by electrochemical techniques including registration of open‐circuit‐potentials, polarization curves and impedance spectra. Extracts were made in cell culture media and acidic saline and used for MTT test for cytotoxicity and HET‐CAM method for irritation. <jats:italic>Results:</jats:italic> The mean amount of elements released in the acidic saline were in μg cm<jats:sup>−2</jats:sup> : Cu:632; Al:210; Ni:144; Fe:122; Zn:48; Mn:52. No protective film was formed on the surface of the alloy, as extensive corrosion was observed in both saline and artificial saliva. The corrosion rate was higher in saline than in artificial saliva. Acidic extracts of the alloy diluted up to 64 times reduced cell viability with 80% or more. The extract induced coagulation of the blood vessels of the CAM and was rated as moderate irritant solution. <jats:italic>Significance:</jats:italic> The nickel–aluminum bronze showed high corrosion rate caused by an inability to create a protective surface layer. High levels of toxic elements were found after static immersion testing, and the corrosion products had a distinct adverse effect on the biological activity. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009</jats:p>