Root Canal therapy (Endodontics)

Understanding your teeth and its pulp tissue

The pulp tissue - Your teeth are in fact calcified objects with a hollow space within. The hollow space is known as the pulp chamber, which comprises of the nerves, arteries, veins, lymph vessels and connective tissue that nourish the tooth.

Root canals - The nerve of each tooth enters at the tip of its root and runs through the centre of the root in small root canals that merge ultimately with the pulp chamber. The number of canals varies according to the teeth. Generally, the front teeth have a single root canal while molars often have three or more canals.

Initially, the nerve tissue plays an important aspect in the development and formation of teeth.  On formation its function is to preserve the tooth’s health and vitality by:

  • Retaining the organic components of the tooth’s mineralised tissues namely the dentin and enamel, by supplying nutrients and moisture
  • Producing new tooth structure to protect the nerve from injury or infection

However, once the tooth’s nerve tissue has to be removed as a result of infection, it should not affect you in any manner.

What is the purpose of a root canal treatment?

A root canal treatment is performed when the pulp tissue of the tooth has become infected, in order to prevent the formation of abscess and eventual spreading of the infection to the surrounding tissues.

How is the pulp damaged?

The pulp can be damaged as a result of:

  • Untreated tooth decay – causing bacteria to spread into your tooth and infect the pulp.
  • Severe gum disease – causing gums to pull away from the teeth, thereby creating a gap called a periodontal pocket, which traps bacteria that can infect the pulp.
  • Injury – due to accident that affects and infects the pulp.

What happens if the tooth is left untreated?

If left untreated it leads to the formation of an abscess, which is the collection of pus as a result of the multiplying bacteria, and it pushes beyond the root tips. As the abscess expands within the bone, the tooth rises slightly out of its socket making it feel tender when you bite down. Without treatment, this infection can further spread to the surrounding tissues and nerves resulting in

  • Nausea
  • Fever
  • Difficulty in swallowing

How can root canal treatment help?

Root canal treatment removes the infected pulp and disinfects the pulp chamber thereby stopping the spread and formation of further infection. This helps to retain the teeth in its natural form.

What are the indications for a root canal treatment?

By Symptoms

  • Persistent toothache
  • Presence of tenderness in your gums near a tooth.
  • Presence of swelling in your gums near a tooth
  • A tooth that is partially or completely darkened following a trauma

By dental examination

  • X-rays - show a dark spot at the tip of the tooth's root, indicating a reduction in the density of the bone surrounding the root's tip as a result of the infection inside the tooth.
  • Routine evaluation - A persistent or recurring pimple on your gums detected by the dentist
  • Due to Exposure of a tooth's nerve during dental work –  may occur when the dentist is carrying out other dental work, in which case a root canal treatment may be necessary to prevent the degeneration of the tooth’s nerve tissue.

What are the factors to consider in a root canal treatment ?

  • Front teeth have fewer canals than the back teeth and hence the treatment for the former tends to be more successful.
  • Though retreatment is possible for the same teeth, the margin of success reduces each time.
  • Complications though rare can occur in some cases

How is root canal treatment carried out?

Root canal treatment may take one or several appointments to complete. It depends upon the extent of infection in the tooth and the number of root canals to be treated.

At the first appointment

  • The area to be treated is numbed with a mild anaesthetic
  • The dentist places a rubber dam over the tooth to keep it dry and prevent the bacteria in saliva from infecting the root being treated.
  • The pulp chamber of the tooth is accessed by drilling a hole into it.  In case of posterior teeth the access point is usually made through the centre of the chewing side while in the front teeth the hole is made behind the tooth.
  • X-rays are used to evaluate the depth of the canals and cleaning equipments are used accordingly to clean out the infected tissue in the canals.
  • The dentist may wash out the teeth periodically to clean out debris from the canal.
  • X-rays are taken to verify whether the roots have been cleaned across their entire depth.
  • A temporary filling is then placed and the tooth is sealed

At the next appointment

  • The dentist numbs the treatment area using a local anaesthetic
  • The rubber dam is placed over the teeth.
  • The tooth is once more accessed by drilling it.
  • The temporary filling is removed and dentist ensures that the root canals are dry and free from infection
  • The root canals are then filled using gutta percha
  • X-rays are taken to verify if the gutta percha has filled the canals completely
  • The dentist then covers the tooth using a permanent filling or crown.

What can you expect following the procedure?

The tooth might feel a little tender for a day or two which can be alleviated by pain killers prescribed by the dentist

What are the after care guidelines to follow following root canal treatment?


  • Clean your teeth at least once a day with a fluoride toothpaste
  • Floss or use interdental brushes to clean in between the teeth daily

Eating habits

  • Avoid chewing or biting down until the treatment has been completed
  • Reduce the intake of sugary snacks and drinks as it limits the exposure of your teeth to acid, and hence the risk of decay.
  • Minimize chewing on the tooth that has undergone or is undergoing root canal treatment until advised otherwise by the dentist to:
    • Prevent the temporary filling from coming out and contaminating the interior of the tooth again
    • Prevent tooth form breaking or cracking before it has been fully restored

Further dental work for restoring the functionality of the tooth

Often the tooth that has undergone root canal treatment may require restorative dental work to make them sturdier.  Also, restoration work also helps to seal the teeth protecting its interior cavity from contamination by bacteria or other debris.  The common restorations recommended by your dentist will vary according to your dental condition, and may comprise of any of the following:

1. A dental post – Posts are placed in teeth that have large portions of their tooth structure missing. To increase the stability of the tooth, dentists will have to increase the amount of tooth that extends up to the centre of the dental crown. This can be accomplished by using a dental post which will serve as the anchor for the filling material used to increase the height of the internal core of the tooth.

A dental post is a rod made out of metal placed in the canal space by drilling and removing some of the gutta percha filling. The post is then cemented and a core of filling material is used to fill around the upper portion of the post.

2. A dental crown – Used to restore or repair a broken tooth and improve its appearance. Crowns are made of porcelain or metal and serve as excellent seals for tooth by preventing the contamination by bacteria or other debris in the mouth.


  • The treated tooth is prepared by trimming it into a tapered form, which will extend up to the centre of the dental crown to be placed and thus provide stability.
  • An impression of the tooth is then taken and is sent to the dental laboratory to prepare a custom made crown for the tooth.
  • The prepared crown is then cemented into place.

Repeating root canal treatment

Generally, the positive outcomes of a root canal treatment last a lifetime. However, if infection does return the treatment can be repeated.

Are there any other alternatives to root canal treatment?

Tooth extraction is the only other alternative where you can have the tooth with the infected pulp removed. However, it is always better to retain your natural teeth than have them removed.

When does root canal treatment fail?

Signs of a failed root canal treatment

  • Mild to severe tooth pain
  • Slight to more pronounced tenderness or swelling in the gums in the area near the tooth that can either be in a persistent or transient mode following root canal treatment.

Factors influencing the failure of the treatment

  • Shape of the tooth's root canals – If they have branches or forks they may be difficult to detect and therefore are overlooked during treatment.
  • Unexpected number of root canals – When a tooth has root canals that are tiny they may be overlooked during treatment
  • Undetected cracks in the root of the tooth
  • Defective or inadequate dental restoration allowing bacteria to seep into the inner core and recontaminate
  • Disintegration of the tooth seal with the passage of time causing bacteria to recontaminate the tooth
  • Tooth structure that has broken as a result of the treatment and require restorative work for stability
  • The treated teeth are not impervious to tooth decay and gum disease, in which case if extra hygiene is not maintained it can result in the loss of the teeth
  • Poor response of certain bacteria to the root canal treatment

What are the complications associated with root canal treatment?

  • Breaking off of the dental instruments or files in the root canal while cleaning the pulp chamber. This can be removed later but only by a specialised endodontist.
  • Infection as a result of incomplete treatment or filling as a result of the root canals being complex or not being detected on the X-ray
  • Poor response of certain bacteria to the root canal treatment