Root canal treatment is a dental procedure used to treat infection at the centre of a tooth (the root canal system). It's also known as 'endodontics'.

The infection is caused by bacteria that live in the mouth and invade the tooth. This can happen after:

tooth decay
leaky fillings
damage to teeth as a result of trauma, such as a fall or sports injury

MULTIPLE VISIT ROOT CANAL TREATMENT

Root canals may be treated in one or multiple visits. Most root canals can be treated in one visit. The exceptions are

1) extremely infected teeth where your dentist may choose to leave some medication in the tooth for a week or two before completing the root canal or
2) Complications from the procedure and complex cases i.e. ease of access, number of root/canal, a root canal. Teeth with multiple roots and canals and teeth with very small canals may take several visits
3) Generally, front teeth have one canal and the back teeth have multiple canals

PREPARATION

Before having root canal treatment, your dentist may take a series of X-rays of the affected tooth. This will allow them to build up a clear picture of the root canal and assess the extent of any damage

Root canal treatment is usually carried out under local anaesthetic (painkilling medication that numbs a specific area of the body). In some cases, where the tooth has died and is no longer sensitive, it may not be necessary to use a local anaesthetic.
Occasionally, teeth may be difficult to anaesthetise. On these occasions, your dentist can use special local anaesthetic techniques to ensure your treatment isn't painful
Your dentist will place a RUBBER DAM around the tooth to ensure it is dry during treatment. The dam will also prevent you swallowing or breathing in any chemicals the dentist uses.

PROCEDURE

The general sequence of a root canal procedure is as follows:

Step 1: A small access hole is drilled through the biting surface of an affected back tooth or from behind a front tooth, allowing access to the pulp chamber and root canals for treatment.
Step 2: The diseased and dead pulp tissue is removed from the tooth with specially designed instruments used to clean out the root canals and pulp chamber. This is not painful; the area is numb and the tissue being removed is either dead or dying. Once the pulp, along with the nerves contained in it, is removed, the tooth itself can no longer feel pain.
Step 3: The canals are disinfected with antiseptic and antibacterial solutions
Step 4: The canals are then shaped with tiny flexible instruments to allow them to receive root canal fillings and sealers. The canals are washed and cleaned again to remove root canal debris prior to sealing them.
Step 5: Root canal fillings are selected that will exactly fit into the freshly prepared canals. Usually a rubber-like material called gutta-percha is used to fill the canal space together with adhesive cement called a sealer. Sealing the canals is critically important to prevent them from becoming reinfected with bacteria
Step 6: A temporary or permanent filling material will then be placed to seal the access hole that was made to treat the canals, and the dental dam is removed.