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."

For the purposes of this discussion, so to use terminology that people seem to be most familiar with, we will use the terms "nerve" and "nerve tissue" to refer to a tooth's pulp tissue.

Teeth are hard calcified objects but their inner aspects are not completely solid. Inside every tooth there lies a hollow space which, when a tooth is healthy, contains the tooth's nerve tissue dentists use the following terms to refer to various portions of this nerve area

The pulp chamber: This is a hollow space that lies more or less in the center of the tooth.

The root canals: Each tooth's nerve enters the tooth, in general, at the very tip of its root(s). From this entry point the nerve then runs through the center of the root in small "root canals" which subsequently join up with the tooth's pulp chamber.

You might think that a tooth's nerve tissue is vitally important to a tooth's health and function, but in reality it's not. A tooth's nerve tissue plays an important role in the growth and development of the tooth, but once the tooth has erupted through the gums and has finished maturing the nerve's only function is sensory (it provides the tooth with the ability to feel hot and cold).

In regards to our normal day to day oral functions the sensory information provided by a single tooth is really quite minimal. Dentists realize that on a practical level it is pretty much academic whether a tooth has a live nerve in it or not. If a tooth's nerve tissue is present and healthy, wonderful. But if a tooth has had its nerve tissue removed during root canal treatment that's fine too, you will never miss it.