Root canals are necessary to save teeth if decay has progressed in the nerve inside the tooth. This usually causes the nerve to become infected (abscessed) or the nerve to die (become necrotic). A root canal might also be indicated when a tooth fractures into the nerve inside the tooth.
Tooth abscesses can very painful. Before antibiotics, root canals had a bad reputation for being painful procedures. If the patient is provided pre-operative antibiotics 7-10 days before a root canal procedure, this helps to get the infection under control, thus making it possible to completely anesthetize the tooth. Also, current anesthetics now work better in an infected environment.
During the root canal, the nerve and other infected or diseased tissue is removed from inside the tooth. The cleaned nerve chamber is then filled with a hard rubber-like material called gutta percha. The tooth is built up in preparation for a crown. Sometimes this buildup requires a stainless steel post, depending on the amount of the tooth that needs to be replaced. However, due to composite bonding materials, we have less need to rely on posts for retention.
When the nerve is taken out of a tooth, the blood supply for the tooth is also lost. The tooth becomes non-vital, or dead, but it still can be functional for a patient’s lifetime if properly protected. A non-vital tooth is more brittle than a vital tooth, so to prevent the tooth from fracturing away, a gold or porcelain crown should be placed over the tooth.