Root canal therapy refers to the process by which a dentist treats the inner aspects of a tooth, specifically that area inside a tooth that is occupied by its "pulp tissue." Most people would probably refer to a tooth's pulp tissue as its "nerve." While a tooth's pulp tissue does contain nerve fibers it is also composed of arteries, veins, lymph vessels, and connective tissue.

Initially a tooth's nerve tissue plays an important role in the formation and development of the tooth. Then, once the tooth has formed, the function of this tissue becomes one of helping to preserve the tooth's health and vitality. The nerve tissue keeps the organic components of the tooth's mineralized tissues (dentin and enamel) supplied with nutrients and moisture. The nerve tissue also produces new tooth structure (reparative dentin) as is needed so to help to wall off and protect the nerve from insult or injury (such as advancing tooth decay).

A tooth's nerve tissue does provide a sensory function but this role is probably different from what you expect. Under normal circumstances the nerves inside our teeth provide us with very little information. Yes, when activated by extremes in pressure, temperature, or severe insult (such as a cracked tooth or advancing tooth decay) teeth do respond with a painful sensation. But under normal circumstances the nerves inside our teeth remain relatively "quiet."

At this point you might be thinking that if you push on your tooth with a finger or close your teeth together you will feel a pressure sensation. Because of this you might assume that that sensation must come from the nerve inside the tooth. Well, in reality, that sensation comes from the nerves found in the ligament that binds the tooth to the jawbone, not from inside the tooth itself. This implies then, from a standpoint of the normal functions we perform with our teeth, that the presence of a live nerve inside a tooth is somewhat academic. If a tooth's nerve tissue is present and healthy, wonderful. But if a tooth has had its nerve tissue removed as a part of root canal treatment then that's fine too. You will never miss it.