Corrosion of coupled metals in a dental magnetic attachment system.

Implants and magnetic attachments are becoming widespread in dental treatment. Their associated use, implants and magnetic attachments, can be seen often too. In those cases, it is difficult to avoid coupling of different metals. The corrosion behavior of the metals is expected to be different depending on whether it is found in an isolated or a coupled condition. Potential corrosion couples in a dental magnetic attachment system among titanium, ferromagnetic stainless steel, gold alloy type IV, and gold-silver-palladium alloy were studied by an immersion test in 1% lactic acid for 7 days and potential/current density curves were measured. Corrosion of titanium and ferromagnetic stainless steel seemed to be accelerated by coupling with gold alloys or gold-silver-palladium alloys. On the other hand, the corrosion amount of gold alloy and gold-silver-palladium alloys were attenuated by coupling.