Why Would Someone Need a Root Canal?

No one wants to be announced by the dentist that a tooth needs a root canal. Here are some of the main reasons why a tooth should get root canal therapy. Knowing those circumstances might also help to prevent them:

• An infection that is at the apex of a tooth (periapical lesion) means that the whole pulp tissue is irritated or infected. A periapical lesion can only be seen on an x-ray. In this case the tooth needs a root canal, following antibiotic therapy.
• A cavity can grow and reach the dental pulp chamber, where the pulp tissue is located, including the nerve. The bacteria contained in the decay infect the pulp directly and the tooth would need root canal therapy to stop the infection.
• If a tooth has had an advanced fracture, and there is not enough tooth material left to repair it with a conventional filling, root canal therapy must be done on that tooth to be able to put a post that will hold a filling or a crown.
• If a tooth has suffered from trauma, the pulp can be irritated permanently and needs to be removed from the tooth by root canal therapy.
• The dental pulp can also be irritated by a filling that is too deep, which was done by a dentist following tooth decay that was very at a very advanced stage.

Source: Root Canal Therapy
In French: Pourquoi aurait-on besoin d’un traitement de canal?