Inside a tooth there are hollow chambers, or canals. These canals have a soft tissue in them called pulp tissue. The pulp tissue contains blood vessels, nerves and connective tissue, and helps to grow the root of your tooth during development. A fully developed tooth can survive without the pulp because the tooth continues to be nourished by the surrounding tissues.
Removal of the pulp tissue is necessary when the tissue becomes inflamed or infected. Inflammation or infection can have a variety of causes, but all comes down to bacteria somehow entering the pulp chamber. If pulp inflammation or infection is left untreated, it can cause pain or lead to an abscess.
During root canal treatment, a small access hole is created in the crown of the tooth. Small instruments and disinfectant rinses are used to carefully remove pulp tissue from inside the canals.
After all the tissue is removed, the canals are measured and prepped for a filling material. The filling material is a rubber-like substance called gutta-percha. The gutta-percha is placed with sealer and is heated up and packed into the canal space.
In most cases, the tooth is temporarily sealed with cotton and a temporary filling. This filling will last up to 4 to 6 weeks, until you can get back into your general dentist for your final restoration. Most teeth require a crown to be placed afterwards. After restoration, the tooth continues to function like any other tooth.