Extensions and modifications of standard electrochemical techniques, accounting for unique
conditions related to biological considerations, have proved useful in attacking some problems
related to biocompatibility of the Biomaterial. Some authors have demonstrated that modern
electrochemical techniques can be used to clarify some difficult problems in the field of biomaterials.
Precious alloys can not be apply for all cases especially such as long range bridges or prostheses.
For this reason, Ni-Cr as well as Co-Cr casting alloys have been used for dental application as
alternatives to precious alloys. The biocompatibility of Ni-Cr alloys have been questioned because
of their corrosive, allergenic, and even mutagenic potentials.
The nature of passive films on metals and alloys is the ultimate factor which controls their
corrosion behavior. There is little reliable information on the effects of the physical and chemical
factors involved in the tissue response to an implant and the associated ionic release on the cellmaterial
interaction.
Depending of the casting process during the production of a dental prosthesis, these alloys may
show different phases, ones may be more stable than other. For this reason, the development of a
quick and simple method for determining the corrosion behavior as a control test in the production
Biomecánica, 9 (1), 2001, pp. 66-70
67
of a dental prosthesis is of great interest.
The purpose of this work was to show some results on the corrosion behavior of two different
commercial alloys: Wiron 99 ( Ni-Cr alloy) and Aurolloyd kf (Au alloy). These results were obtained
by several electrochemical methods: Open Circuit Potential vs time and Liner Sweep Voltammetry
for Wiron 99, and Open Circuit Potential vs time and Cyclic Voltammetry for Aurolloyd kf. In the
case of the Ni-Cr alloys, it is concluded that with the combination of both methods, it is possible to
know how the corrosion behavior of casting individual dental Ni-Cr alloy prosthesis is, and in the
case of Au alloy, it is concluded that the differences in electrochemical behavior strongly depend of
surface oxides formed. These results showed that one of the studied combination, Eoc-Rp or Eoc-CV
characterization, could be selected as control test after casting of individual prosthesis.
