Corrosion of the η′(Cu‐Sn) phase in dental amalgam

Publisher Website
Google Scholar
Abstract
Previous studies have shown preferential corrosion of the η′(Cu-Sn) phase in highcopper dental amalgam both in vitro and in vivo, while samples of pure η′ have shown high corrosion resistance. To clarify this contradiction, samples of pure η′ crystals mixed with other phases were prepared and tested. Evaluation of the corrosion resistance was based on the results of coulometry at constant potential and potentiodynamic polarization. The corrosion susceptibility of η′ in the matrix of γ(Ag-Hg) was considerably higher than the susceptibility of isolated η′. The susceptibility of pure η′ also could be increased by plating it will small amounts of Hg. It was concluded that in dental amalgam, the presence of mercury in the phases surrounding η′ reduces its resistance to corrosion. Although η′ is more resistant to corrosion than γ2(Sn-Hg) which appears in low-copper amalgams, it is the least corrosion resistant major phase in high-copper amalgams and can suffer deterioration.

This publication has 9 references indexed in Scilit: