Elaine,

Hal Huggin indicates on his website that Porcelain contains metal oxides, such as aluminum oxide. Plus, apparently the porcelain is fired onto a metal base that fits onto the tooth. The base is sometimes made of gold (expensive and not very strong), but more often stronger and cheaper substitutes are used like nickel (which is carcinogenic).

I love the progesterone cream I use, but like you said, you could use an herbal supplement instead. I've actually used a combination called Wild Yam & Chaste Tree and it worked very well. I just found that for me, since I take a lot of other supplements, the progesterone cream was easier (Pro-G-Yam 500).

Let us know if you find any other info on the porcelain.