Electrochemical investigations regarding the bioavailability of silver after potentiodynamic corrosion load of precious metal alloys part 2: dental alloys

摘要

The spectrum of commercial dental alloys has been essentially expanded during the last years. Thetoxicological effects of dental alloys depend mainly on their element specific corrosion behaviour inthe oral cavity. The present study demonstrates the electrochemical boundary conditions regarding the possibleformation of AgCl-corrosion products, for which cytotoxic effects has been established, by means ofspecially adapted electrochemical in-vitro test programs. The prevalence of the developed corrosionmode was proved for two electrolytes and four daily used dental alloys containing different amountsof silver. The results show, that a biological relevant assessment of the released silver ions in bothelectrolytes, induced by anodic metal dissolution, is only reliable if the measurement takes intoaccount the silver ions within the electrolyte as well as the superficial immobilized amount of silverchloride corrosion products. Thus especially from a biological point of view, interface processes likethe formation of immobilized corrosion products seem to be a relevant parameter for the completetesting of biocompatibility of metallic biomaterials. To sum up it can be concluded, that the dental alloys investigated in the course of this study havenot shown any adverse susceptibility to corrosion with respect to the clinical practice and cantherefore be classified as well biocompatible.