Ion release from gold/platinum dental alloy: could release of other elements be accountable in the contact allergy attributed to the gold?

Objectives: The release of metal ions (Al, Ag, Au, Ca, Cd, Co, Cr, Cu, Mg, Mo, Ni, Pd, Pt, Ti, and Zn) from the commercial gold/platinum (Au/Pt) dental alloy of declared composition was studied. Methods: Au/Pt was soaked in pH 6.0 phosphate buffer, 3.5 pH phosphate buffer and pH 3.5 mixture of lactic, formic and acetic acid, and incubated at 37 degrees C for 1, 2, 3, 4, 5, 6, 7, 14, 21, and 30 days. Six samples (n = 6) of every solution were prepared for any time period. Inductively coupled plasma atomic emission spectroscopy was used for analysis of the released elements. Results: Results demonstrated release of only Cr, Cu, Fe, and Zn from the tested Au/Pt dental alloy (ANOVA, p < 0.001 for buffer, time, and interaction, respectively); however, only Cu and Zn were declared. Conclusions: The undeclared chromium from Au/Pt dental alloy, or some other element might be responsible for the contact allergy thus far attributed to the gold.