>>52557960You actually have nerves and fleshy parts inside your teeth. These can get infected, especially if you get a cavity. If they do get infected you most likely need a root canal, where they basically drill into yhe tooth, suck out all the fleshy bits, fill it in so essentially its a dead tooth, then glue a fitted cap onto the top of the tooth to cover the holes. Its very painful but necessary because an infected tooth can spread the infection to neighboring teeth.