Root canal treatment is necessary when the pulp (soft tissue inside your teeth containing blood vessels, nerves, and connective tissue) becomes inflamed or diseased. During root canal treatment, we remove the diseased pulp. The pulp chamber and root canal(s) of the tooth are then cleaned and sealed. If the infected pulp is not removed, pain and swelling can result, and your tooth may have to be removed.

Causes of an infected pulp could include:

• Deep cavity
• Repeated dental procedures
• Cracked or broken tooth
• Injury to the tooth (even if there’s not a visible crack or chip)

If you continue to care for your teeth and gums, your restored tooth could last a lifetime. However, regular checkups are necessary; a tooth without its nerve can still develop cavities or gum disease. Most of the time, a root canal is a relatively simple procedure with little or no discomfort involving one to three visits. Best of all, it can save your tooth and your smile.

Source: http://www.mouthhealthy.org/en/az-topics/r/root-canals