Patient Information

Endodontic treatment [root canal treatment]

What is Endodontic treatment?

What is endodontic treatment

Endodontic treatment treats the inside of the tooth. The tissue is called the pulp and contains nerves and blood vessels that nourish the tooth.   Endodontic treatment is necessary when the pulp becomes inflamed or infected.  Endodontic treatment removes this infected or damaged tissue from inside the tooth.  The inflammation or infection can have a variety of causes: deep decay, repeated dental procedures on the tooth, faulty crowns, or a crack or chip in the tooth. In addition trauma to a tooth may cause pulp damage even if the tooth has no visible chips or cracks.  If pulp inflammation or infection is left untreated, it can cause pain or lead to an abscess. 

What is endodontic treatment 3

After the pulp is removed, the pulp chamber and root canals are cleaned, disinfected and then filled and sealed with a rubber-like material called gutta-percha.

Root1 Indian Ink
Upper Premolar
Second Upper Central Incisor
Upper Central Incisor
Lower Molar
Lower Canine


I produced these images during my Diploma. The black areas inside these teeth demonstrate the canal systems. They have been stained with Indian ink. All the black areas have to be cleaned and disinfected during root canal treatment. These images show the complexity of root canal systems.


Why do I need root canal treatment?

The most common cause of pulp damage is severe decay or a fracture that exposes the pulp to bacteria that may cause infection.  Other causes of pulp damage include traumatic injury, a cracked or loose filling, repeated fillings in a tooth or if a tooth has been crowned or is part of a bridge.  Periodontal disease [gum disease] can also cause infection of the pulp tissue.


How successful is root canal treatment?

Initial root canal treatment should have a success rate between 85-95% depending on the circumstances and this will be discussed with you at your initial consultation. 


Can all teeth be treated endodontically?

Some heavily filled teeth will need a restorability assessment to decide if the tooth is restorable.  Endodontic treatment can be performed only if the root canals are accessible and can be adequately cleaned and sealed.  The tooth must also have sufficient bone support.  We only carry out treatment where we can give a good long term outlook.


Can treatment fail?

Problems can occur if the tooth develops decay or the restoration on the tooth fails allowing bacteria to re contaminate the root canal system.  On occasions despite good care the tooth may not heal as expected.  Further endodontic treatment or surgery may be carried out if appropriate.  A tooth that develops a crack can also be cause of failure and may result in loss of the tooth.  There may be a poor response of certain bacteria to the root canal treatment.  Some root canal systems are very complicated and bacteria may persist in inaccessible areas within the root canals causing failure of the treatment.


What other treatment options might I have?

Endodontic treatment saves teeth that otherwise would need to be extracted.  If you have your tooth extracted you will then have a gap and can either leave the gap or consider replacing the tooth with:

  1. A Removable denture
  2. Adhesive [Maryland] bridge or a conventional bridge
  3. Implant retained crown


What is rubber dam and why do I need to have it?

A rubber dam is a rectangular sheet of latex or silicone. During root canal treatment it is used to isolate a tooth or teeth from the rest of the mouth. Its purpose during root canal treatment is to prevent contamination of the root canal system by saliva and any bacteria contained within it.  


What do I do after the endodontic treatment is completed?

Usually a definitive restoration of the tooth is required and it may be that your Dentist will advise on a restoration that protects the tooth from fracture such as an onlay or a crown, particularly if the remaining tooth that is left is considerably weakened. 


How many visits will there be?

Root canal treatment is a skilled and time consuming procedure.  It will usually take 1-2 visits but may require more depending on the complexity of the tooth. Most visits are between 1-2 hours.


Will I experience any discomfort?

Endodontic treatment typically involves little or no discomfort.  All root canal treatment will be performed under local anesthesia.  Often there is pain before treatment from the inflamed pulp and endodontic treatment aims to alleviate this.  Cleaning the root canals may cause some slight tenderness but usually pain killers such as Ibuprofen or Paracetamol can alleviate this.

In 1-2% of cases there may be some pain and/or swelling [known as a “flare up”].  You should contact the surgery for advice.  Antibiotics are rarely needed in root canal therapy.


Follow up appointments.

It is recommended to have a follow up radiograph [x-ray] taken a year after the root canal has been completed to check the healing of the tissues around the root of the tooth.  There may be a need for further follow up depending on the circumstances.



Some very heavily restored teeth could fracture during or after the root canal treatment and if your tooth requires a crown then it is important to have your tooth crowned as soon as possible after the root canal treatment had been finished.

There are several complications that occur but these happen rarely:

  1. We use very fine stainless steel and Nickel Titanium hand and rotary files to prepare root canals and there is always a risk that these could separate.  If this happens you will be informed and the options will depend on where the instrument has separated.
  2. Sometimes canals are very fine and it can be difficult to locate them and then get an instrument into them.  In these cases there is a small chance that in attempting to find the canal a perforation can occur, where the instrument breaches the side of the root.  You will be advised if there is a greater chance of this happening.
  3. We use irrigants to disinfect the canal systems and there is a risk that these can be extruded into the tissues surrounding the root, if this happens you will be given advice about what to do.  This is a very rare event.


What is Endodontic re-treatment?

Teeth that have had endodontic treatment can last as long as natural teeth but in some cases the treatment can fail or symptoms can persist.  This may happen shortly after the treatment has been performed or even years following the treatment.  In these cases it may be possible to carry out the treatment again, a procedure called endodontic re-treatment.


Why does the treatment fail?

It can fail for a number of reasons.  If it was not possible to treat very narrow or curved canals well enough or the canals were not fully cleaned during the initial procedure.  The tooth may have additional complicated anatomy that was not found on the initial treatment.  A defective/inadequate dental restoration or cracks in the tooth can also cause bacteria to re infect the canal system.


Is re-treatment more complicated?

Usually it is more complicated than initial treatment as the tooth is normally fully restored with a permanent restoration.  This can range from a simple filling to a full coverage restoration such as a crown or as part of a bridge.  In addition to this a post may have been placed inside the root prior to a final restoration being placed.  This creates difficulty as access to the root canals is more difficult.  Also the canals have been filled previously with gutta percha root filling material and this must be removed before they can be instrumented and cleaned again.  All these obstructions make the process more complicated.