Root Canal, or endodontics, is the process of removing the nerves from the roots of a tooth. A root canal is often necessary to save an infected tooth. If an infected tooth is left alone for a long period of time, an abscess can form. An abscess will show up on an x-ray as a dark spot below the apex of the root. This is actually bone loss in the jaw. It is very important to catch this problem before it deteriorates too far.