Root canal therapy is provided to teeth in which the nerve of the tooth has become infected or damaged and is no longer vital. Once the nerve is dead the nerve needs to be removed to avoid reoccurring infections which more than often happen. Root canal therapy consists of extracting the dead nerve from one or multiple canals in the tooth, and filling the tooth with restorative material. Root canal therapy may need to occur for a few different reasons, the most common reason is deep decay in which the decay has hit the nerve and damaged it.