Faculty Collaboration Database

Corrosion of CoCr and NiCr dental alloys alloyed with palladium. J Prosthet Dent 2011 Jan;105(1):35-43

Date

01/05/2011

Pubmed ID

21194586

DOI

10.1016/S0022-3913(10)60188-6

Scopus ID

2-s2.0-78650773792 (requires institutional sign-in at Scopus site)   31 Citations

Abstract

STATEMENT OF PROBLEM: A new subclass of casting alloy composition involving the addition of palladium (25 wt%) to traditional base metal alloys, thereby raising their classification to that of a noble alloy, has been recently introduced. Little is known about this class of casting alloy, particularly its corrosion properties, which influence its biocompatibility and esthetics.

PURPOSE: The purpose of this study was to evaluate the corrosion properties of 2 new CoPdCr and one new NiPdCr alloy and compare them to traditional CoCr and NiCr alloys.

MATERIAL AND METHODS: The casting alloys investigated were: CoPdCr-A (NobleCrown NF), CoPdCr-I (Callisto CP+), NiPdCr (Noble Crown), CoCr (Argeloy N.P. Special), and NiCr (Argeloy N.P. Star). Cylindrical (4.8-mm diameter) as-cast and oxidized specimens were assessed electrochemically in phosphate-buffered saline at 24°C (n=8 and n=6, respectively). The open circuit potential (OCP) was monitored for 20 hours, followed by linear polarization and cyclic polarization tests. A generalized linear mixed model was used to determine whether differences existed between alloys and to examine the effect of oxidation (α=.05). Representative alloy surfaces were scanned and examined with light microscopy.

RESULTS: The palladium-containing alloys possessed a significantly greater OCP (P<.001); however, their polarization resistance was less and the corrosion current density was significantly greater (P<.05) than their traditional CoCr and NiCr alloy counterparts. Additionally, a greater incidence of pitting was observed in the palladium-containing alloys. Some differences were noted within alloys between the as-cast and oxidized conditions, but a major trend was not observed.

CONCLUSIONS: Overall, the inclusion of palladium in CoCr and NiCr alloys had deleterious effects on electrochemical corrosion properties.

Author List

Sarantopoulos DM, Beck KA, Holsen R, Berzins DW

Author

David Berzins BS,PhD Graduate Program Director for Dental Biomaterials in the General Dental Sciences/Dental Biomaterials department at Marquette University

MESH terms used to index this publication - Major topics in bold

Biocompatible Materials
Chromium Alloys
Cobalt
Corrosion
Dental Casting Investment
Electric Impedance
Electrochemical Techniques
Hot Temperature
Humans
Image Processing, Computer-Assisted
Materials Testing
Metal Ceramic Alloys
Nickel
Oxidation-Reduction
Palladium
Surface Properties
Time Factors
Vacuum