Endodontics is necessary when the pulp (the soft tissue inside the tooth containing blood vessels, nerves and connective tissue) becomes inflamed or diseased. During a root canal, the dentist or endodontist (a dentist who specializes in treating the inside of the teeth) removes the affected pulp. The pulp chamber and root canal of the tooth is cleaned and sealed. If the infected pulp is not removed, it could hurt and swell, and it may be necessary to extract the tooth.

The term "treatment channel" comes from the cleaning takes place in the channels within the tooth root.

The causes of infected pulp may include:
a deep cavity
repeated dental procedures
a broken tooth
tooth injuries (even if there is visible a crack or break)

The pulp is soft tissue which contains nerves, blood vessels and connective tissue. It lies within the tooth and extends from the tooth crown to the tip of the root in the jawbone.
When the pulp is diseased or damaged and can not repair itself, it dies. The most common cause of death is a fractured tooth pulp or a deep cavity. Both problems can allow bacteria to enter the pulp, causing an infection inside the tooth.

Without treatment, pus builds up at the root tip in the jawbone forming a "pus-pocket" called an abscess. An abscess can cause damage to the bone around the teeth. When the infected pulp is not removed, it can result in pain and inflammation. Some byproducts of the infection can damage the jawbone. Without treatment, your tooth may have to be removed.

Treatment often involves channels one to three visits to the dentist. During treatment, a general dentist or an endodontist (a dentist who specializes in problems of the pulp) removes the diseased pulp. Then it clean and seal the pulp chamber and the root canal of the tooth.

A restored tooth can last a lifetime if you continue taking care of your teeth and gums. However, regular visits to the dentist are necessary. While the root of a tooth treated is nourished by the tissues around it, your tooth will remain healthy.