I have a tooth #15 that has been decaying from the inside out, the dentist recommended that the tooth be removed. I have since scheduled the tooth to be extracted, I noticed on my treatment plan a charge for bone replacement graft. Is it really nessesary to have a bone graft done? Do I have an option to reject the bone grafting? One last thing. What causes a tooth to decay from the inside out? concerned because this is the 3rd tooth that has done this, thankfully the others were caught in time.