I started using a tooth powder a while back because I was having a lot of sensitivity in certain areas of my teeth, and I also have some ongoing problems with 2 of my wisdom teeth, and I am almost totally non-compliant with any type of medical "care," which is to say that I really don't ever go to a dentist, much less let them do anything to me.
So I had read that one of the main problems with toothpaste, besides the fluoride and artificial sweeteners, is the glycerin, which coats the teeth with a thin slippery covering, and then the natural process of mineralization which would normally happen from the saliva's contact with the tooth, cannot occur. Almost all toothpastes, including the natural ones, have glycerin. So I switched to tooth powder. Now my teeth have almost zero sensitivity (!) and my wisdom teeth are not bothering me much either, although that's a slightly different problem, perhaps not related to glycerin.