Root canal treatment (endodontics) is a dental procedure to treat infection at the centre of a tooth (the root canal system). The infection is caused by bacteria that live in the mouth and invade the tooth when:
- tooth decay occurs
- The seal around fillings fails
- teeth are damaged by trauma, such as a fall
Tooth structure
A tooth is made up of two parts:
- The crown is the part of the tooth that is visible in the mouth.
- The root extends into the bone of the jaw, anchoring the tooth in position.
These parts are composed of the following structures:
- Enamel is the hard outer coating of a tooth.
- Dentine is a softer layer that supports the enamel and forms most of the tooth.
- Cementum is a hard material that coats the root surface.
- The root canal system supplies the nutrients to the tooth through the blood supply and sensation via the nerve supply.
The root canal system contains the nerve and blood supply to the tooth, extending from the crown of the tooth to the end of the root. To complicate matters each root canal is like an inverted tree with billions of nerve branches. A single tooth can have more than one root canal. If bacteria invades the root canal, the nerve and blood supply will begin to die. Eventually the bacteria begins to multiply inside the main trunk and the numerous side channels. The bacteria and the bacterial toxins released will eventually breach the small exit hole where the blood vessels and nerves enter from the jaw bone.
This process continues as there is nothing to stop more bacteria pouring into the root canal, which causes the tissues around the end of the tooth to become red and swollen. This can cause your tooth to become painful and, in extreme circumstances, your face may become swollen (dental abscess).
Some indications that a tooth may need a root canal are:
- Pain when you bite, touch it or push the tooth (toothache is usually described as one of the most excruciating pains)
- Sensitivity to heat
- Sensitivity to cold that lasts longer than a couple of seconds
- Swelling near the affected tooth
- A discoloured tooth, with or without pain
- A broken tooth
Options for Treatment
To treat the infection in the root canal, the bacteria needs to be destroyed. This can be achieved by:
- removing the tooth (extraction)
- attempting to save the tooth by removing the bacteria from the root canal system (root canal treatment)
In root canal treatment, the bacteria are destroyed from inside the root canal system. The root canal is filled and the tooth is sealed with a filling or crown. In most cases, the inflamed tissue at the end of the tooth will heal naturally.
Root canal treatment should not usually be painful because local anaesthetic is always used. The procedure is very successful and should be no more unpleasant than having a filling.
How long does it take?
In the majority of cases we are able to complete your root canal treatment in a single session, but in some circumstances we will need to schedule further treatments. The number of sessions is determined by how long it takes to eliminate the infection.
Some teeth may be more difficult to treat because of the position of the tooth. Some teeth have many and curved root canals that are difficult to locate.
In this clinic, as with all aspects of our dentistry, we use the finest single use flexible titanium alloy root treatment instruments to increase the success rate of our root treatments.
Re-Treatments of Canals
We are often asked to treat a tooth that has already had a root canal treatment carried out elsewhere. This may be necessary for any of several reasons.
It may be that during treatment, the area was insufficiently sterilised and the trapped air has triggered bacterial regrowth causing inflammation and pain.
The side of the tooth was punctured during treatment. This can happen if the canal is curved or difficult to locate. The instruments are flexible and bend to follow the curve of the canal, but sometimes the instrument makes a small hole in the side of the tooth.
A canal was missed or was not fully cleaned out. Locating canals within the tooth can be difficult. If a canal or an offshoot isn’t located and cleaned out, the tooth can remain infected and the procedure will have to be repeated.
A file may break. The tip of a file may break off inside the tooth. Usually, it’s possible to leave the piece in the tooth and finish the procedure. But if the cleaning was not finished, the file piece may have to be removed. To minimise the risk of this we use special rotating instruments which reverse when too much pressure is applied. To provide better visibility and hence a higher standard of result we use surgical magnification loupes as used in general surgery procedures.
Root canal channels tend to be very fine. As a result, it can be very difficult to introduce the disinfecting liquid to the bottom of the channel. Many times air pockets become trapped. These areas can become reinfected, leading to possible root canal treatment failure. With the advent of the waterlase this problem can be eliminated. Unlike conventional endodontics which achieves disinfection of the root canals, laser endodontics achieves total sterility of the root channels.
