Introduction: Dental casting alloys made of high noble alloys,
noble alloys, and predominantly base metal alloys have been
used in the fabrication of fixed and removable prosthetic dental
appliances. Nickel–chromium (NiCr) alloy has been widely
used in the fabrication of fixed and removable partial denture
frameworks owing to its superior physical properties and lower
cost, but their resistance to tarnish and corrosion is debatable.
Aim: The aim of this study is to evaluate and compare the corrosive
behavior of four commercially available NiCr alloys with
that of a high noble alloy.
Materials and methods: Four commercially available NiCr
alloys (study groups) and high noble alloy were used to study
the corrosion by cyclic polarization test, and the parameters
that were evaluated are corrosion potential (Ecorr), breakdown
potential (Eb), repassivation potential (Ep), and corrosion
current (Icorr).
Results: When all the findings from the four parameters were
evaluated, the values of the control group were significantly
higher than the study groups, and among the four study groups,
group III alloy was significantly more resistant to corrosion than
the other alloy groups.
Conclusion: Within the base metal alloy study groups, group
III behaves to be more resistant to corrosion. Both nickel and
chromium ions were released during the corrosion process,
but the percentage of nickel ions was relatively higher than
chromium ions.
Clinical significance: With the advent of new dental alloys in
the market, the biocompatibility of dental materials is of critical
concern and the evaluation of corrosive behavior of new dental
alloys is highly warranted.
Keywords: Chromium, Corrosion, Cyclic polarization, Nickel,
Noble alloy.
How to cite this article: Begum R, Ariga P, Jain AR. Evaluation
of Corrosive Behavior of Four Nickel–chromium Alloys in
Artificial Saliva by Cyclic Polarization Test: An in vitro Study.
World J Dent 2017;8(6):477-482.