I realize this is outside the scope of cosmetic chemistry, but I'd really be interested in trying to make my own dentifrice. The problem is, that some ingredients are really hard (impossible?) to come by. I can find baking soda (calcium carbonate) easily enough, but none of the various grades needed to make a sensitive toothpaste. I was also looking for arginine bicarbonate, but I can't find a supplier anywhere. Does anyone know where to find the suppliers? Thanks!