A root canal is a procedure used to save a tooth that otherwise might have to be extracted. Performed by either general dentists or endodontists, root canals help teeth that are experiencing physical irritation or tooth pain as a result of bacteria in the pulp (the soft material of the tooth containing blood vessels and nerves). The bacteria can result in an abscess---an area of pus, indicating infection. Root canals also help save teeth that have experienced trauma, such as a hit, according to Torres and Ehrlich Modern Dental Assisting.
The dentist can use the end of a mouth mirror handle to perform a percussion test by tapping on the top of a molar or on the edge of a front tooth. The mirror handle is used to check for inflammation in the tissues around the root tip of the tooth. In addition, a dentist can place ice, dry ice or carbon dioxide near the gum line on the problem tooth to determine the response of the tooth to cold. An irreversible problem is noted if the cold relieves the pain or causes a strong, lingering pain. Initial X-rays also provide information about the problem tooth.
If a tooth is vital (alive) prior to a root canal treatment, the dentist will use a local anesthetic agent to numb the area. Oral or inhalation sedatives also are available for patients who are very apprehensive about the procedure. To isolate and disinfect the area of the tooth being worked on, the dentist then uses an item called a rubber dam---a thin, stretchable latex or latex-free material---as well as an antimicrobial solution called sodium hypochlorite.
The dentist uses a high-speed hand piece to create an opening in the tooth. An endodontic explorer helps to locate root canal openings, and a spoon excavator removes pulp tissue and decay. A broach is a thin, flexible instrument with fishhook-like extensions that remove vital pulp tissue from the canal. Then, several files (K-type file, Hedstrom file and reamer file) clean, shape and enlarge the pulp canal. Rubber stops that slide onto the files prevent the files from perforating the tooth's root tip. After the canal is clean and shaped, sodium hypochlorite irrigates the canal. Paper points then dry the canal.
The dentist uses gutta-percha points to fill the dry pulp canal. Gutta-percha is an organic substance that is solid at room temperature and becomes soft when heated. The points are made from a rubber material that comes from the Palaquium gutta tree. Spreaders (instruments with pointed tips) and pluggers (instruments with flat tips) condense and adapt the gutta-percha in the canal.
A root canal sealer is a cement-type material the dentist uses with the gutta-percha to seal voids during the filling process. These sealers can include calcium hydroxide, zinc oxide-eugenol and glass ionomer. Following this, the dentist places a temporary filling on the tooth until it can receive a permanent crown.