Schille C. et al

Title: Corrosion behavior of dental CoCr alloys made by different digital workflow processes compared to cast CoCr alloys.
Authors: Christine Schille, Ernst Schweizer, Jürgen Geis-Gerstorfer
Published: May 6, 2017


Dental metallic restorations can be made alternatively by casting or CAD/CAM procedures such as milling and selective laser melting. This raises the question as to how far the material properties differ. The aim of this study was to evaluate the corrosion behavior of dental porcelain fused CoCr alloys manufactured by the CAD/CAM techniques using wet milling of solid blanks (Organic), dry milling of ‘wax-like’ blanks and subsequent sintering (Ceramill Sinron) and selective laser melting (Remanium Star CL) compared to the cast CoCr alloys Remanium Star, Girobond NB and Ankatit U. Corrosion measurements according to ISO 10271 were performed with all alloys. Static immersion tests over 1, 4 and 7 days were used in artificial saliva. The electrolytes of all samples were analyzed by ICP-OES and the corresponding ion release rate was calculated for each alloy and immersion time. Furthermore, electrochemical corrosion measurements were carried out in 0.9% saline. Open-circuit-potential measurement over 2 h were carried out, followed by anodic polarization from -150 mV ~Ecorr to 1 V at a speed of 1 mV/sec. The results revealed a total ion release below 50 µg/cm² for all alloys investigated which is below the limit value of 200 µg/cm² according to ISO 22674.