I read an article on this a few years ago and I was astounded that very few people and dentists are aware of it. Here's something similar to what I read.
http://www.lymecommunity.com/forums/ubb ... 165/page/1
Scared me I no longer use fluoride toot paste and I have a medical grade water filter for consumed water.
Now there's a study that all the drugs we're taking are getting back into our water system mostly by urination.
Bill S.