Corrosion behaviours of the dental magnetic keeper complexes made by different alloys and methods

Research Summary

Dental prostheses: Cutting down on corrosion

Silver-palladium-gold and gold-platinium alloys used as magnets for dental prostheses resist corrosion more than cobalt-chromium alloys. In removable prostheses, such magnets are attracted to a keeper, which is placed either on a treated root or a metal framework fixed in the mouth, enabling the prostheses to remain fixed. In the oral environment, the function of these attachment systems declines due to corrosion. Jie-Fei Shen at Sichuan University, Chengdu, China, and colleagues compared the corrosion resistance of three alloys and two common methods (casting or laser-welding) for fabricating the alloy-keeper complex. Microscopy revealed the structure of the corroded surfaces, indicating that the cobalt-chromium alloy is more prone to corrosion than the other alloys tested. The laser-welded cobalt-chromium and silver-palladium-gold alloys were shown to be more resistant to corrosion than equivalent samples made by the casting technique.