What is Root Canal Treatment (Endodontic Therapy)?
What's it purpose? What does it do?
You might find yourself in the situation where you know your tooth needs root canal treatment. And you do understand that it offers a way of saving your tooth. But you don't really understand how it does that.
Well, this is what our pages are all about. They explain the purpose of root canal treatment, its goals and objectives.
What else do we cover?
To further your understanding about this subject, our pages also delve into topics such as:
- What to expect during your procedure, as well as after.
- Ways teeth are rebuilt after their treatment (including post and core with crown placement).
- Treatment costs. / Reasons why a tooth's therapy sometimes fails.
- Possible treatment alternatives (including implant placement vs. root canal).
1) What is root canal treatment?
Root canal (endodontic) therapy refers to the process where a dentist treats that space within a tooth (its root canals and pulp chamber) originally occupied by its "nerve" (or, more accurately, pulp tissue).
(Need help with some of these terms? Here's information about tooth anatomy, as it pertains to root canal therapy.)
2) What's the purpose of having root canal?
Root canal treatment is used to resolve pathologic conditions inside a tooth that have affected both its nerve tissue, and probably the tissues that surround the tooth too. It sets the stage so healing can take place.
This is accomplished using a two-staged process.
A) Cleaning the tooth.
This portion of the procedure removes compromised tissues and/or contaminates from within a tooth's nerve space.
B) Sealing off the tooth's inner space.
A) Cleaning the tooth. - What does this step accomplish?
Although most people don't realize it, root canal treatment is used to treat a number of different nerve-related tooth problems. For example, this same fix is used when a tooth's nerve tissue is either acutely inflamed, in the process of dying or even dead.
And although each of these states are different, what they all have in common is that they involve (or will involve) a situation where the tooth's nerve space contains contaminates that will ultimately leak out of the tooth's root tip and persistently irritate (inflame) the tissues that surround it.
So, the underlying goal of the cleaning portion of the root canal procedure, is to remove as many of these irritants (or items that will degrade into irritants) as possible. These items include bacteria, nerve tissue, the organic debris left over from the breakdown of nerve tissue, and bacterial toxins.
B) Sealing off the tooth's inner space. - Why is this important?
The sealing aspect of the root canal procedure has to do with filling in and sealing off the, now empty, nerve space inside the tooth. Related to this goal, there are two objectives.
- One of them is for the filling material to create a seal that prevents contaminates from seeping back into the tooth. Certainly, once a tooth has been cleansed, you don't want it to become recontaminated.
- The other goal is just the opposite. You also don't want any irritants still contained in the tooth to seep out.
How is it that things seep out, hasn't the tooth been cleaned?
Root canals don't have a precise shape like we show in our illustrations. They're often more like a river, where the main channel may give birth to small branches that separate off for a while and then return.
Our point here is this. Even after the dentist's most diligent of efforts, it's likely (due at least in part to the convoluted shape of the tooth's root canal system) that some debris still remains. So, the sealing process insures that these contaminates remain entombed within the tooth and don't seep out and continue to inflame the tissues that surround its root.
3) Why are contaminates harbored inside a tooth such a big issue?
Here's the purpose of going to all of the trouble of having root canal treatment.
Imagine that your finger is infected, like from a cut. If it is, your body's immune system will immediately kick into gear. It will transport white blood cells, by way of your blood and lymphatic vessels, to and from the infected area to combat the invading bacteria. And, in most cases, your cells will win. They will kill off the offending bacteria.
Infections in teeth are a different situation.
Now, consider a similar scenario with a tooth. Once a tooth's nerve tissue has started to degenerate (die), and bacteria have taken up residence inside the tooth's nerve area, there is no way for white blood cells to effectively get at the bacteria to combat them. The blood and lymphatic vessels inside the tooth that are needed to transport them either no longer exist, or at least have been severely compromised.
This means that the nerve space inside a tooth can provide a nice cozy cave-like location for bacteria to live because it's a place where your body's defense mechanisms have a hard time getting at them.
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 infection will overwhelm your body's defense mechanisms and pain and swelling will ensue (an acute tooth abscess).
Here's what root canal treatment does.
Endodontic therapy provides for a third outcome, one where the infection is not just cordoned off but actually cleared up. Root canal treatment assists your body's infection-fighting process by removing or sealing off the bacteria and tissue irritants inside your tooth that it can't effectively reach and deal with.
4) Tooth anatomy as it relates to root canal treatment.
a) Where precisely in a tooth is its nerve?
Teeth are not solid objects. Inside every tooth there lies a hollow space that contains its nerve tissue. Dentists use the following terms to refer to various portions of this space:
A) Pulp chamber.
This is the hollow area that lies, more or less, in the center of the tooth's crown (that part of the tooth positioned above its gum line).
B) Root canals.
A tooth's root canals run from the apex (tip) of its root up to its pulp chamber.
Terms: Pulp tissue vs. Nerve.
Most people refer to a tooth's pulp tissue as its "nerve." And although we use this same slang terminology on our pages, doing so is only partially accurate. While pulp tissue does contain nerve fibers, it is also composed of arteries, veins, lymph vessels, and connective tissue.
b) Nerve space variations in teeth.
Teeth always have just one pulp chamber but the number of individual root canals that they have can vary widely.
- Every tooth will have at least one root. Some have 2, 3 or possibly more.
- Each tooth root will have at least one root canal. The roots of some teeth are well known for usually having 2 or more.
This comparison demonstrates how varied the nerve space inside different types of teeth can be:
- Upper center teeth (incisors) typically have just one root and one root canal.
- Lower molars usually have 2 roots and 3 canals (see x-ray grahic to right).
- Most upper molars have 3 roots and at least 3 (and frequently 4) canals.
What does the number of root canals mean to you?
The number of canals that a tooth has will affect you, the patient, in the following ways:
- The cost of a tooth's treatment is typically based on the number of individual canals that it has. The greater the number, the higher the cost.
- Treatment time is affected by the number of canals being treated. It is more time consuming for a dentist to treat a tooth with 4 canals as opposed to one just having a single canal.
5) Isn't a tooth's nerve important?
You don't really get much "feeling" input from a tooth's nerve.
Under normal circumstances the nerve tissue inside our teeth provides us with very little information.
Yes, when subjected to pressure or temperature extremes, or exposed to severe insult (like advancing tooth decay or the formation of a crack), teeth do respond with a painful sensation. But other than that, the nerves inside our teeth remain relatively unresponsive.
You might think that when you push on your teeth, or else close them together, the pressure sensation you feel is a signal from within your tooth. Actually, this sensation comes from the nerve fibers found in the tissues that surround the root, not from inside the tooth itself.
After your treatment, you'll never miss your tooth's nerve.
All of the above implies that, from a standpoint of the normal function, the presence of live nerve tissue within a tooth is pretty much optional. If it's present and healthy, then wonderful. But if it's been removed as a part of root canal treatment, then that's fine too. You'll never miss it.