Co-Cr alloys have excellent corrosion resistance, but in the
ceramic firing process, they are exposed to high temperatures that may affect the alloy corrosion causing ions' release.
We aimed to study the effect of ceramic firing on Co, Cr ions rele
ase from Co-Cr frameworks.
So, 30 Co-Cr models were fabricated and divided randomly into
two equal groups: 1st group: (control), 2nd group: exposed to ceramic firing conditions. Then samples were submerged in artificial saliva for one month, and measurements of released ions were performed using atomic absorption spectrometry.
Concentrations of both cobalt and chromium ions released in
control group (in μg/l) were less than those in 2nd group (without a
statistically significant difference).
We can consider ceramic firing as safe and acceptable process
that slightly increase Co, Cr ions release from Co-Cr frameworks.
Nickel metal may cause systemic toxicity and allergy
The compatibility of dental casting alloys correlates with
their release of elements .The aim of this study was to
specify the relationship of the release of nickel from Ni-
Cr dental alloys wi
th their composition , and to
determine the effects of thermal treatment of Ni-Cr
alloys during porcelain firing process on the release of
nickel .
Ranging Five Ni-Cr alloys commonly used in clinical
practice were used, They have different nickel
percentage Ranging between ٥٩،٣ and ٨١ % , two of
them containing beryllium .
