eli5: Why can’t our bodies grow new teeth, even though it can grow bones?
Teeth trace their origins back to fish scales and not bone.
Bones are living tissue, because it is living it can be regrown.
Enamel is not living tissue. You can remineralize it to some degree, but it can’t be regrown once it has already been formed. Humans do not have further instruction on a cellular level to form new teeth past our adult teeth so no more are produced.
We can’t regrow entire bone. You cant regrow your femur.
Osteo tissue (bone) does grow around injuries but its complicated and its not the same. Think of it more like a scab over a cut in your skin.