Definition & Overview

A root canal is one of the most common procedures performed in the field of restorative dentistry. It is characterized by the removal of the infected pulp found underneath the upper layer of a tooth due to the build-up of abscess or infection.

There's more to the teeth than meets the eye. The enamel (the hardest part of the tooth) and the dentin are the first things a person can see since they serve as the outer covering of the tooth. Underneath them is a chamber with pulp. While the tooth develops its roots, the pulp inside the chamber nourishes it through its network of nerves, tissues, and blood vessels. Once the teeth have fully matured, the pulp ceases to function, but it is retained in the chamber.

However, there are cases wherein bacteria, due to a crack on the teeth or significant tooth decay, or damage to the pulp due to trauma, can lead to inflammation or infection. This can threaten the gums and cause enormous pain. The condition is treated with a root canal therapy.

In the procedure, the entire pulp is removed before it is filled. The dentist then has the option to add a new crown, among others, to restore the appearance of the tooth and prevent further damage.

Who should undergo and expected results

Not all types of toothaches require a root canal treatment. It is only recommended to those who have a damaged pulp.

Usually, a person with an infected pulp develops initial symptoms including but not limited to temperature sensitivity (the tooth suddenly becomes sensitive to very hot or cold drinks and food), loose or cracked teeth, pain in the tooth, and difficulty in eating and chewing.

However, the most ideal way to diagnose it is through an X-ray, which provides a comprehensive picture of the inflamed pulp, its location, and the extent of the infection. The x-ray images can also help the dentist plan the course of action especially if the root canal is to be performed in a tooth that is not easy to reach or if more than one root canal is affected.

As for the results, a root canal therapy eliminates the infection and swelling. In several cases, it also saves the rest of the tooth from further damage. However, unless a new crown is added or the decayed tooth is dealt with correctly, the effects of the root canal may not be as effective. Nevertheless, root canal can restore the tooth's basic function.

How the procedure works

The root canal procedure is not often performed during the first visit. Normally, it takes around 2 to 3 appointments before it is carried out.

During the first visit, consultation and thorough assessment are performed. This is also the best time to carry out certain tests including X-rays and pulp test, which can be electric or thermal. On the second visit, the results of the tests are typically presented to the patient before the endodontist discusses the most appropriate treatment plan. Other health conditions that may have not been discussed during the first visit may also be talked about during the second appointment.

In the third visit, the patient undergoes the actual procedure. A root canal is only an outpatient process and takes roughly an hour to complete, so it can be easily squeezed into the day-to-day schedule. It also doesn't require sedation unless it is necessary to calm the patient. Otherwise, a local anesthesia is enough.

After the anaesthetics are administered to numb the area, the affected tooth is then isolated from the rest of the mouth using a rubber dam. First, the tooth is cleaned and any decay is treated accordingly. Then, the chamber is accessed usually through the top (or sometimes at the back) using a dental drill. Using measuring tools, the dentist determines the depth of the pulp, making sure everything is removed.

Layers of tissues and pulp are then removed until nothing is left in the chamber. Once the chamber has already been cleaned, it is disinfected to kill off any remaining bacteria.

Once the chamber is completely empty, it will be filled so it will continue to support the structure of the tooth and prevent any entry of bacteria and debris. This can be accomplished by using gutta percha. The dentist may then add the new crown as a form of extra protection to the teeth.

Possible risks and complications

Sometimes the root canal procedure fails. This usually happens when the tooth still suffers from infection even after the entire pulp has already been removed. Normally, however, when there are still bacteria in the chamber, the dentist adds an antibacterial solution rather than a gutta percha. It's only when the infection has subsided that the permanent filling is used.

Pain, is of course, expected especially after the treatment. The dentist therefore recommends pain relievers. However, if the pain remains or even worsens after a few days, the patient should go back to the dental clinic for an assessment.

Some may experience discoloration, but this can be easily settled with teeth whitening.


  • Christian JM. Odontoogenic infections. In: Flint PW, Haughey BH, Lund LJ, et al, eds. Cummings Otolaryngology: Head & Neck Surgery. 5th ed. Philadelphia, Pa: Mosby Elsevier; 2010:chap 12.
  • Pogrel MA. Damage to the inferior alveolar nerve as the result of root canal therapy. J Am Dent Assoc. 2007;138(1):65-69.
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