Advice for patients requiring root canal treatment

About root canal treatment

Your teeth have a core of blood vessels and nerves at their centre. This living tissue is called the pulp and it’s in a space called the root canal. The number of root canals a tooth has varies, depending on how far back the tooth is in your mouth. Your front teeth often have just one root canal, whereas your back teeth may have three or more.

If your tooth’s pulp becomes damaged, the blood vessels may die. This results in a ‘dead’ tooth, which is more likely to get infected

There are a number of ways that your tooth’s pulp can be damaged. These include:

  • decay
  • injury
  • gum disease

All of these conditions can lead to bacteria getting trapped in your teeth. There is then the possibility that your tooth pulp will become infected, causing blood vessels and nerves to die.

Without treatment, a collection of pus (an abscess) can form at the root tip. This can lead to pain and swelling and may cause damage to the bone around your tooth.

The aim of root canal treatment is to get rid of the damaged pulp and the bacteria that are causing the infection. It involves removing inflamed or dead nerves and blood vessels from the centre of your tooth. This is done by drilling a hole through the top of your tooth to the root canal and removing the dead tissue. The empty root canal system is then cleaned, filled and a permanent seal is put over the top of your tooth.

The procedure may be carried out over one or two visits to your dentist. All dentists can carry out root canal treatment, but many prefer not to carry out re-treatment procedures (where a previous root canal treatment has failed) as these may be more difficult and require additional equipment. Your dentist may refer you to an endodontist, who specialises in root canal treatment.

What are the alternatives?

Your dentist may not always be able to repair your tooth with root canal treatment. This may be because your tooth is very seriously damaged by decay or injury or if you have gum disease meaning that your tooth isn’t well supported. Your dentist may recommend that you have the tooth taken out (extracted) instead.

Preparing for root canal treatment

Your dentist will take an X-ray of your tooth to see whether you need root canal treatment and to check the shape of your root system to make sure we can place a root filling.This can help to show how far any decay has spread, if there is an abscess, how many root canals your tooth has and to check the shape of your root system to make sure we can place a root filling.

If you have a dead tooth or one with severely damaged pulp, root canal treatment may be the only way to repair it. However, it’s important to discuss with your dentist what is involved in this treatment before deciding to go ahead with it.

About the procedure

Your dentist will give you an injection of local anaesthetic. This completely blocks pain from the area and you will stay awake during the procedure. You may not need to have an anaesthetic if your tooth is dead. Your dentist will discuss this with you.

Your dentist will make a hole in the top of your tooth, and remove the dead or diseased pulp through this hole. He or she will then clean the empty pulp cavity and may put in some medication to help get rid of bacteria.

This may be all your dentist does at your first visit – if so, he or she will put a temporary filling on your tooth to keep it sealed until you go back for further treatment. However, your dentist may decide to fill the cavity immediately if the root canal infection hasn’t caused you any serious problems.

If you had a temporary filling, when you go back to your dentist he or she will remove this and then fill the root canal with a suitable material. This is likely to be a rubber substance called gutta percha. A permanent filling or crown is then placed over the top of your tooth to protect your filled root canal and your tooth. Your dentist may recommend a crown made from gold or porcelain. If your dentist thinks it’s necessary, he or she may also place a metal or plastic rod inside the canal to help support the crown.

What to expect afterwards

You will usually be able to go home when you feel ready. After a local anaesthetic it may take several hours before the feeling comes back into your mouth. Take special care not to bump or knock your mouth or bite your tongue, particularly when you’re speaking, drinking or eating.

You may need pain relief to help with any discomfort as the anaesthetic wears off. If you need pain relief, you can take over-the-counter painkillers such as paracetamol or ibuprofen. Always read the patient information leaflet that comes with your medicine and ask your pharmacist for advice if you have any questions.

You may find that the tooth that was treated changes colour slightly. If your tooth does change colour, you may be able to have treatment to correct it.

After your treatment, it’s important that you take care of your repaired tooth as you would any other. Brush your teeth at least twice a day and visit your dentist regularly. Your root canal treatment should be assessed by your dentist after a year and reassessed at regular intervals after this.

What are the risks?

Root canal treatment is commonly performed and generally safe. However, in order to make an informed decision and give your consent, you need to be aware of the possible side-effects and the risk of complications.


Cleaning your teeth may cause slight tenderness, but this is only temporary.

Possible complications

Root canal treatment is not always successful for no reason we can find. Commonly the root canal system of posterior teeth can be complicated with multiple roots which can be very curved and twisted which make them difficult to fill adequately. If your dentist feels your tooth may be especially difficult to fill they may refer you to a specialist called an endodontist.

Sometimes we are unable to find all or some of the root canals inside a tooth. This is because these root canals can become very small or blocked so unfortunately we are unable to fill all the root canal system of the tooth which may mean infected material is still present. Obviously the long term lifespan of the tooth can be compromised. If the tooth is painful or shows evidence of infection your dentist may advise you to see a specialist endodontist or advise extraction of the tooth.

We use high performance instruments to carry out root canal treatment but sometimes these instruments can break in the root canal system due to the fact they are very small and thin. If this happens your dentist will inform you. Commonly these fractured instruments cause no problems, but if the tooth is painful or shows evidence of infection again your dentist may advise you to see a specialist endodntist or advise extraction of the tooth.

It’s unlikely that you will have any further problems after root canal treatment. If your tooth does become infected again, your dentist can repeat the procedure. However, repeated treatments are generally not as successful.

Very occasionally after root canal treatment, you will still have inflammation at the tip of your tooth. You may need to have a surgical procedure called an apicectomy to remove the root tip.