Have you tried hydroxyapatite? Just curious. (The chemical name is hydroxyLapatite, but it's usually spelled without the L in toothpastes. There's a heated debate about this on the wikipedia talk page.)
I can't say for sure. The first non-fluoride toothpaste, and the one I used for the longest amount of time, was Coral White brand[0]. Hydroxy(l)apatite is not listed as an ingredient, but I also found that it has been derived from coral since at least 1974[1]. Best I can do is... maybe?
