>>/890660/
Try soap. Pure soap, fat + a base (at most salt as in addition, perhaps can get away with a bit of essential oil, pure soap does not tastes bad, additives make it does).
One of the ingredients of an average toothpase is soap anyway. Plus baking soda, sand, rubbing alcohol (or something similar), and fluoride.
Fluoride is unnecessary for teeth health. Your teeth needs calcium and phosphorus, just like any other bones you have. Your body uses your teeth as a calcium storage, and sucks the calcium out from them if you lack in it pregnancy can cause severe teeth decay for women if doesn't take calcium in access. Not sure about the phosphorus, but should take 1g of calcium each day. Preferrably with Vit D, for that's needed for the chemical process in restoring calcium in your teeth.
Fluoride does add a hard film onto your teeth which could be nice if all your teeth are 100%. But it has some adverse effect, I can't recall from the top of my head, I think it prevents the restoration of calcium.
There are some other minerals, like magnesium that binds to teeth, but I think magnesium makes them brittle, and the rest too.