it seems like it's something evolution didn't get around to. and, save me your nonsense about god - if anything, it's an argument against creation. what kind of sadistic creator would create a being that can't repair their own teeth? no - we're just dealing with a consequence of living past our evolutionary best before date. your teeth fall out for the same reason you get alzheimers.
but, if god doesn't exist, we don't have to worry about usurping it's role. we can see biology as a playground.
so, is this something we can use stem cells for, or what? is there some future in regenerative dental technology?
our teeth don't heal, but they should. and, let's hope we can figure that out, eventually.