First, any dental gold that is under porcelain is essentially removed from soluble contact with the body, the porcelain being impermeable - the couple of other elements in it in small quantities are pretty benign which I listed in my post, and they are added for temperature/melting point issues as well as strength.

Anyone not sensitive to a heavy metal like mercury is probably from another planet, but remember it is about volume of exposure, and how much mercury could leach out over how long a period of time from a small filling? This question has been looked at by the ADA and others, and the material is still being used today after those inquiries.

Also remember that when you think of alloys, that the individual elements are no longer available as their original element, but are now part of a compound, or molecularly bound in a new structure that makes them in most cases unavailable.

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