Corrosion Behavior of Noble Metals in Different Oral Media

Abstract

In this first study, the corrosion behavior of the noble (Au, Pd, Rh, Cu, Ag, Pt, Ir) metals studied in 0.1M citric acid (CA), 10% carbamide peroxide (CP), artificial saliva (AS) and in the presence of CP, mouthwash (MW) and in presence of AS, and 0.1M NaCl solutions as oral solution. Electrochemical methods investigated with open circuit potential, impedance spectroscopy, current-potential and linear polarization measurements. Metal electrodes immersed in different oral solutions during a week for the determination of total metal cations. These cations analyzed by ICP-OES/MS. This article outline determined with corrosion tendencies of the noble metals and the amount of these ions passing through the human body. Scanning electron microscope (SEM) images showed that gold surface damaged in the presence of the CP. Additionally, the surface examined with EDS. It is concluded that the corrosion rate of noble metals increased in the presence of carbamide peroxide, due to the additional reactions pathways mediated by hydrogen peroxide anions.

Keywords: Noble metals, Pilling-Bedworth, Hydrogen Peroxide, Artificial Saliva, Mouthwash

DOI: 10.7176/JSTR/5-4-14