title: Corrosion behaviour of cobalt-chromium dental alloys doped with precious metals.
abstract: Precious metal based dental alloys generally exhibit a superior corrosion resistance, in particular enhanced resistance to pitting and crevice corrosion, compared to non-precious metal based alloys such as CoCr alloys. A new generation of Co-Cr alloys enriched with precious metals (Au, Pt, Ru) have now appeared on the market. The goal of this study was to clarify the effect of the precious metals additions on the corrosion behaviour of such alloys. Various commercial alloys with different doping levels were tested by electrochemical techniques in two different milieus based on the Fusayama artificial saliva and an electrolyte containing NaCl. Open circuit potentials, corrosion currents, polarization resistances, and crevices potentials were determined for the various alloys and completed by a coulometric analysis of the potentiodynamic curves. In addition, the microstructures were characterised by metallography and phase compositions analysed by EDX. The results show that the presence of precious metals can deteriorate the corrosion behaviour of Co-Cr alloys in a significant way. Gold doping, in particular, produces heterogeneous microstructures that are vulnerable to corrosive attack.
authors.affiliation: PX-Tech, PX Holding S.A., Bd. des Eplatures 42, CH-2304 La Chaux-de-Fonds, Switzerland. lucien.reclaru@pxgroup.com
authors.forename: Lucien
authors.initials: L
authors.lastname: Reclaru
authors.forename: Heinz
authors.initials: H
authors.lastname: Lüthy
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Eschler
authors.forename: Andreas
authors.initials: A
authors.lastname: Blatter
authors.forename: Christian
authors.initials: C
authors.lastname: Susz
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry; D002858:Chromium Alloys / Q000032:analysis* / Q000737:chemistry*; D003343:Corrosion; D003722:Dental Alloys / Q000032:analysis / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods*; D006046:Gold / Q000032:analysis / Q000737:chemistry*; D008422:Materials Testing; D010984:Platinum / Q000032:analysis / Q000737:chemistry*; D012428:Ruthenium / Q000032:analysis / Q000737:chemistry*; D012463:Saliva / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D002858:Chromium Alloys; D003722:Dental Alloys; D010984:Platinum; D006046:Gold; D012428:Ruthenium