Hi HB, thanks. I read about that ingredient, I think in a Colgate product and something about it maybe being not good - my memory leaves me -. I use a natural toothpaste now that has neither that ingredient or flouride, but I notice my teeth are not as white (even though my natural paste includes sodium bicarb and papain) so now and then I use whitening strips with heavy peroxide. Called recurring anthous ulcers - very worrisome at first as no pain and that usually means auto immune disease, but I found the paper on flouride and the ulcer left in a few days, and did not recur until I tried flouride again as a test. Thank you for your post.
ps: our dentists here complain that almost no one has cavities and have not had in twenty years because of flouride, but there have been many movements to get it out of our water. I don't trust all our regulations anymore when I see how drug plants are inspected (not!).
Hope you are both feeling better CLKD.