Endodontics is a branch of dentistry that involves the treatment of dental pulp. When a very deep cavity has formed and it reaches down to the level of the dental pulp, the tooth will need to undergo a root canal, or endodontic therapy. During endodontics the tooth is thoroughly cleaned down to its root with specific tools that allow the apex of the root to be reached, and once cleaned a seal is placed at the apex to prevent the formation of new infections. Common symptoms include acute neuralgic pain extending to a portion of the face (upper or lower depending on the location of the cavity), throbbing pain and the formation of minor or extensive swelling (also know as an abscess).