[Metal elements from intraoral metal restorations].

Purpose: To detect the metal element from intraoral metal restorations.
Methods: A small sample was taken from each intraoral metal restorations. Energy-dispersive X ray fluorescence spectrometry (EDXRF) was used to detect the metal elements from them.
Results: From 14 suspected patients of dental metal allergy, 120 intraoral metal restorations were detected. The ten most frequent elements detected,in decreasing order of frequency, were Ag, Cu, Au, Pd, Zn, Sn, Co, Cr, In and Mo. The types and percentages of alloys containing these elements were Au-Ag-Pd alloys (65%), Ag-Sn-Hg amalgams (2.5%), Ag alloys (5.4%) , Au alloys (14.6%), Ni-Cr alloys and Co-Cr alloys (10.1%), other alloys (2.4%). In these, Ag-Sn-Hg amalgams (2.5%) are in lower using rate than 10 years before (16%). Ni, Co, Cr alloys are in same using rate as 10 years before. There are 12 patients with two to five kinds of different alloys present at an oral environment. In one of 12 patients,five kinds of different alloys were present within an oral environment.
Conclusions: In patients suspicious of dental metal allergy, co-existence of different metals alloys was often detected, which indicated that in order to prevent dental metal allergy, heterogeneous metal and metal alloys containing Hg and Ni should be avoided as much as possible.