Teeth have a core of blood vessels and nerves at their centre; this is known as the pulp. The number of root canals a tooth has varies. Generally your back teeth have 2-4 canals, whereas your front teeth often have just one canal.
Root canal treatment is required when your tooth’s pulp becomes traumatised or damaged, this can then lead to the blood vessels dying. Teeth that are ‘dead’ are more likely to become infected as they are no longer protected by your immune system.
Root canal treatment, or endodontics, is used to save a tooth when the dental pulp (blood vessels and nerve) dies which can in-turn cause the tooth to become infected. The cause of infection is usually decay under a filling, trauma such as a blow to the face or if the tooth fractures. Without treatment, this can cause a dental abscess resulting in pain, swelling and infection of the jaw bone.
The only alternative to carrying out root canal treatment is to remove the tooth. Although some people would prefer an extraction, it is usually best to keep as many natural teeth as possible.
The aim of root canal surgery is to avoid removal of the tooth where possible. Before surgery, you may be given antibiotics to control any infection that has gone beyond the tooth, to the bone. Root canal treatment is used to access the pulp chamber, clean out what remains of the pulp and fill the chamber with an inert (non-active) material to prevent the infection returning.
How it is performed
Root canal surgery is usually carried out under local anaesthetic, although in some cases, where the tooth has clearly died and is not sensitive, this may not be necessary. Local anaesthetics will not work in an infected area, and your dentist will usually give you antibiotics to settle the infection first and start treatment about a week later.
Your dentist will first access the pulp chamber by making an entrance in the tooth, this is usually in the back of a front tooth or the flat biting surface of a back tooth. Any remaining tooth pulp/debris is then removed.
Once the pulp has been removed, the remaining root canal will be cleaned and enlarged so that it can easily be filled. The root canals are normally an oval shape and may be very fine and difficult to fill, hence the enlargement.
Your dentist will use a series of small instruments to enlarge the canals and make them a regular shape so that the root filling can be placed. The treatment may take several hours to complete, and may be carried out in one, or several visits.
Generally, the front, incisor and canine teeth have one canal, premolars have two canals, and the back molar teeth have three. The more roots a tooth has the longer the treatment will take to complete.
If the treatment is carried out over several visits your dentist may put a small amount of medication in the cleaned canal in between visits to help clear up any remaining germs and bacteria. The tooth will then be sealed with a temporary filling. You may also be given antibiotics to manage and prevent further infection.
Once the root canal has been cleaned out and shaped, the root filling will be sealed tightly into the root canal. The tooth may then be restored with a filling.
Root-filled teeth are more brittle than live ones and in some cases your dentist may suggest placing a crown on the tooth to protect what remains of the tooth structure. In some cases a root-filled tooth may darken, particularly if it has died as a result of a blow and there are several ways for your dentist to treat this.
Root canal treatment is usually very successful. However, if the infection comes back, the treatment can be repeated.