Root Canal What is root canal treatment?   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.   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. Where precisely in a tooth is its nerve? 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. What is the function of a tooth's nerve 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. What is the purpose of root canal treatment? You could say that the purpose of root canal treatment is to create an end result where the tissues that surround a tooth's root will maintain a healthy status despite the fact that the tooth's nerve has undergone degenerative changes. Specifically, we mean that the tissues surrounding a tooth's root are not affected by bacterial infection and/or irritating substances leaking from those inner aspects of the tooth originally occupied by the tooth's nerve tissue. Possibly in more scientific terms, our bodies, as a defense mechanism, will initiate an "inflammation reaction" when irritants (such as those that might seep out of a problematic tooth) have injured or destroyed body tissues. So if we choose to incorporate the term "inflammation" into our description we would say, root canal treatment is the treatment of the inner aspects of a tooth (whose nerve has undergone degenerative changes) so to provide an environment where the tissues surrounding a tooth's root are free of, and will likely to continue to be free of, the presence of inflammation. How does root canal treatment accomplish this goal?  In a nutshell, the process of root canal treatment first removes (as  thoroughly as possible) bacteria , nerve tissue, the organic debris left over from the breakdown of nerve tissue, and bacterial toxins from within the inner aspects of a tooth (the area originally occupied by the tooth's nerve tissue). Each of these items can produce tissue irritants that can cause your body  to activate an inflammation reaction. Subsequently, once this space has been cleansed the second half of root canal treatment involves filling in and sealing up the interior of the tooth. This aspect of the treatment is an attempt to minimize the possibility that bacteria will be able to recolonize the inner aspects of the tooth or that tissue fluids can seep inside the tooth, become stagnant, and subsequently break down. (Either of these situations could produce a state of persistent inflammation in the tissues surrounding the tooth's root.) The seal also contains and encapsulates any debris that could not be fully removed during the cleaning aspect of the root canal treatment process so that it can't leak out and trigger an inflammation reaction. Why go to all of this trouble? If you get an infection, say from bacteria entering a cut in your skin, your body will transport white blood cells to and from the area (by way of your blood vessels and lymphatic system) so to combat the bacteria that have caused the infection. In most cases your body will win the battle and kill off the offending bacteria. The problem with teeth and infections is that once a tooth's nerve tissue has started to degenerate and bacteria have taken up residence in the tooth's nerve area, there is no effective way for white blood cells to get at the bacteria to combat them. The dying nerve's blood and lymphatic vessels used to transport white blood cells will have begun to degenerate too. The net result of all of this is that the nerve space inside a tooth can provide a nice cozy cave-like location for bacteria to persist because it's a place where your body's defense mechanisms can't get at them effectively. With this scenario, at best your body will only be able to cordon off the infection caused by the bacteria living inside your tooth. At worst, this bacterial infection will overwhelm your body's defense mechanisms and pain and swelling will ensue (an acute tooth abscess). The idea behind having root canal treatment is that it provides the bulk of the clean up work for your body. It removes bacteria and tissue irritants that are present inside the tooth, especially those in the locations where your body would have the most trouble combating them. As an end result, once root canal treatment has been completed it provides your body with an environment where its mechanisms are able to clear away any residual bacteria and tissue irritants that may still be present, thus allowing complete healing (resolution of the inflammation) to occur.