When a tooth becomes badly decayed or infected root canal therapy could be needed. Colloquially the process is known simply as a ‘root canal’ although this term is imprecise as the root canal is the central part of the root containing the pulp and nerve endings. Root canal therapy is the process in which this part of the tooth is removed to allow for cleaning. In broader terms the procedure is known as endodontic therapy which aims to eliminate infection and protect the decontaminated tooth from future microbial invasion.
Pulp infection can occur with excessive decay, repeated dental procedures, large fillings, a crack or chip to the tooth or as a result of dental trauma. When the pulp becomes infected bacteria multiply in the root canal chamber and this can create an abscess, an infection which surpasses the root and creates a pus-filled pocket which gathers at the bottom of the root, if left untreated this can have serious consequences. Swelling could occur in the face and neck, bone could start to erode at the base of the tooth and the abscess could drain in to the gums.
A root canal can be performed by a dentist but depending on the severity of the infection and complexity of the procedure you may be referred to an endodontist, a specialist in the causes, diagnosis, prevention, and treatment of diseases and injuries of the human dental pulp or the nerve of the tooth. The procedure may extend to two or three appointments from diagnosis to treatment. To begin an X ray will be taken to determine the extent of the infection and if it has spread to any surrounding bone.
Following the results of the X ray a local anaesthetic will be administered to numb the area around the tooth, although this may not always be necessary considering the nerve is effectively dead, it is sometimes preferable in order to relax the patient. Your dentist will next place a rubber dam in the mouth to protect the infected tooth from saliva. An access hole will then be drilled through the tooth to reach the infected pulp. Using canal files ascending in size the root canal is then cleaned along with water or sodium hypochlorite.
Once the tooth is thoroughly cleaned it is sealed, some dentists may prefer to wait a week before sealing the tooth. Instead they may insert a medication in to the tooth to ensure the infection has been effectively cleaned out, but this depends on the severity of the infection and success of the root canal. If the root canal is not completed in one appointment a temporary filling would be inserted to ensure no debris enters the root canal. In order to fill the interior of the tooth permanently gutta percha is used to fill the root canal, this is a sealer paste and rubber compound. To fill the exterior access hole a filling is fitted. Finally, restoration to the infected tooth may be required since it is usually a tooth which has suffered decay or damage which requires root canal therapy.
Although root canals have a reputation of being of being painful most patients do not suffer any more than they would when have a filling inserted. There may be some pain or discomfort once the procedure is completed and the filling or crown inserted but usually this pain can be effectively treated with over the counter medication such as ibuprofen. It is wise to minimise the amount of chewing and pressure on the infected tooth prior to the completion of the root canal, that is to say before the filling or crown has been fitted.
Root canals have a 95% success rate and many teeth that have undergone root canal therapy will last a lifetime. However, despite your dentist’s best efforts to keep the root canal free of bacteria re-infection can be a risk. The reasons for this could be an undetected crack, more root canals than originally anticipated, an inadequate filling or crown or a break down of the inner sealing. Although a subsequent root canal can be performed in some cases endodontic surgery may be required.
Given that the majority of root canals are required due to tooth decay obviously the main advice is to maintain good oral hygiene in order to avoid the complications that come with tooth decay. However once the decay has reached the point when an abscess occurs there is very little short of a full tooth extraction which can solve the problem. In this case the tooth would be replaced with a bridge, implant or partial denture, however it is always preferred to save you natural teeth.