Undeclared chromium from the gold/platinum dental alloy as etiological factor in the contact allergy attributed to the gold

Gold/platinum (Au/Pt) dental alloy was exposed in vitro to either simulated saliva (Saliva ; phosphate buffer pH 6.0), highly acidic medium resembling the extreme conditions in the oral cavity (Acid ; phosphate buffer pH 3.5), and in lactic acid at pH which occurs under the dental plaque (Plaque, lactic acid pH 3.5). The alloy was immersed in the Saliva, Acid, and Plaque solution for 1, 2, 3, 4, 5, 6, 7, 14, 21, and 30 days. The solution was analyzed for fifteen metals with the ICP-AES. We observed time and solution dependent leaching of Zn, Cu, Fe, and Cr (ANOVA, p<0.01 for solution, time, and interaction comparison). The undeclared chromium from Au/Pt dental alloy may be the principal culprit in the induction of contact allergy attributed to the gold.