Abstract

Objectives: The aim of the present report was to compare the corrosion behaviour of a cast made of brand-new HERAENIUM-NA alloy (Hn) with a cast prepared with the addition of recast material (Hr) and to check if the addition of recast material to the new factorial Ni-Cr alloy would have any influence on corrosion resistance of the rotational casts.
Methods: Corrosion resistance investigations were made using X-ray spectroscopy to determine the amount of metals ions released into solution of artificial saliva (Holland’s modified Fusayama’s formula) and by using the potentiodynamic polarisation method. The structure of the alloys was characterized by means of SEM, EDS. Microanalyses were used to determine the chemical composition of both casts.
Results: The release of metals ions from recast HERAENIUM alloy were higher then those from brand-new alloy which has better corrosion resistance, as was confirmed by the results of a potentiodynamic polarization test. SEM micrographs showed the difference in the casts' microstructures.
Conclusions: The changes of microstructure of dental Ni-Cr alloy caused by addition of recast material could cause changes in corrosion resistance. The results show a decrease in corrosion resistance of alloy with recast additions. Thus, the use of a mixture of alloys is not recommended.

Keywords: Ni-Based Alloys, Cast, Corrosion Resistance, Potentiodynamic Polarisation, SEM