Document details

Galvanic Corrosion of Two Non Noble Dental Alloys

Author(s): Capelo, Sofia cv logo 1 ; Proença, L cv logo 2 ; Fernandes, JCS cv logo 3 ; Fonseca, ITE cv logo 4

Date: 2013

Persistent ID: http://hdl.handle.net/10174/9802

Origin: Repositório Científico da Universidade de Évora

Subject(s): dental alloys; Wiron®88; Remanium 2000+; ions release; galvanic couples


Description
This study aims to evaluate the corrosion resistance of two nonnoble dental alloys, namely, the Wiron®88 (Ni–Cr–Mo) and the Remanium 2000+ (Co–Cr–Mo–W). A noble alloy, the V-Gnathos® Plus (AuPt) previously studied was also considered for the purpose of comparison. The study was conducted in artificial saliva, pH 7.1, at 37 °C, by cyclic and linear sweep voltammetry, electrochemical impedance spectroscopy and chronoamperometry. The Rp value of the alloy of high contents of Ni, the Wiron®88, was 26.2±0.2 kΩ cm2 and of the one with high contents of Co, the Remanium 2000+, was 22.5±0.6 kΩ cm2. Data from linear polarization resistance and electrochemical impedance spectroscopy lead to the same order for the resistance against corrosion. The order from the less to the more reactive alloy is: Wiron®88 → Remanium 2000+. The galvanic cell obtained by coupling the two nonnoble alloys presents very low cell potential (a few mV, -18 mV), while the galvanic cell between one noble alloy (the V-Gnathos® Plus) and the Wiron®88 showed a higher cell potential (-104 mV). Both galvanic couples, under short circuit, have lead to the release of cations, namely, Co2+, in the case of the Wiron®88Remanium 2000+ and Ni2+ for the Wiron®88V-Gnathos® Plus, galvanic couples, respectively, with the ionic concentrations reaching values of 12.15 and 7.30 μg L-1 (7.30 ppb), respectively. SEM micrographs obtained after 25 days immersion in artificial saliva, at 37 °C, showed the formation of well-defined pits on the surface of the two non-noble alloys.
Document Type Article
Language Portuguese
Editor(s) Antonijevic, Milan M.
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