What are you talking about? Teeth are living and are only considered dead if the living tissue or pulp dies or is otherwise removed. I have another question that I'm interested in seeing your answer to. If a root canal is done and a proper coronal seal is achieved with a proper restoration, how is it that the remaining bacteria that can't be removed proliferate? Certainly these organisms are anaerobic and don't need oxygen to survive, but without a food source at their disposal, how can they survive?