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 it is also fibers 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?

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.

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.

How do you know when your tooth needs root canal treatment?

It will take an examination by your dentist to determine if root canal treatment is indicated for your tooth. Not only must your dentist determine if the treatment can be an appropriate solution for your situation but also that the overall condition of the tooth in question warrants the time and expense involved.

Here are some situations where root canal therapy might be the proper solution:

• A tooth is currently causing you pain or else has a history of being painful.
• You have noticed the presence of tenderness and/or swelling in your gums near a tooth.

There can be times when you have a tooth that is in need of having root canal treatment but you are unaware of this fact because there has been no swelling or pain associated with the tooth.

A) Problem teeth identified by x-rays.

The nerve tissue inside a tooth can degenerate and die quietly. The death of a tooth’s nerve is not always a painful experience. In these instances a tooth’s need for root canal treatment can remain undiscovered, even for some years. This is because the virulence of the infection inside the tooth is low and your body’s defensive mechanisms, while not being able to clear up the infection totally, are able to keep it in check.

Dentists often discover teeth that need root canal treatment during routine x-ray evaluations. In the most obvious of these cases the dental x-ray will show a dark spot at the tip of the tooth’s root. This dark spot indicates that there has been a reduction in the density of the bone surrounding the root’s tip. This bone damage has occurred as a result of the infection that is present inside the tooth.

B) A persistent or recurring pimple on your gums.

Sometimes a tooth whose nerve has died will produce a pimple like lesion on a person’s gums. The presence and/or size of these pimples (dentists call them fistulous tracts) can come and go. Because they are literally drains for pus from an infected tooth, a person might notice that they discharge a bad taste (the pus). It is possible that a dentist will discover this type of lesion while performing a routine examination, even though the patient hasn’t noticed it at all.

C) Exposure of a tooth’s nerve.

There can be times when your dentist will find that your needed dental work has resulted in the exposure of your tooth’s nerve. The term “exposure” used here simply means that your dentist, while performing your dental work, has literally been able to visualize your tooth’s nerve tissue. Sometimes a patient will feel a little prick of pain when the exposure occurs. However, many times a patient is totally unaware of the event.

An exposure can lead to the degeneration of a tooth’s nerve tissue. Your dentist may determine that in your situation it is best to go ahead and perform root canal treatment on the tooth now so to avoid possible problems and complications with the tooth later (such as a painful tooth abscess).

D) Teeth which have been traumatized in an accident.

The nerve tissue in teeth which have a history of having been traumatized (such as being bumped in an accident) can deteriorate, thus leading to the need for root canal treatment.

Immediately after the traumatic event the outlook for the nerve’s health can be difficult to predict. Sometimes traumatized teeth do quite well, even for many years.

It is always possible however that at some point the health of the tooth’s nerve tissue will degenerate and subsequently die (often without symptoms). A tip off that the nerve tissue inside a tooth is undergoing degenerative changes is that the tooth, in comparison to its neighbors, appears darkened.

Will you experience pain during your root canal treatment?

We’d be the first to acknowledge that root canal treatment has a reputation for being painful, but we’d be the last to agree that this reputation is deserved. It seems most likely to us that the majority of derogatory remarks you hear in regards to having a root canal almost certainly must have included in them references to the pain and discomfort that the person experienced leading up to receiving treatment.

For the average person and the average case, root canal treatment is a nonevent and not any more uncomfortable than having a filling placed. If your confidence needs a little bolstering…

You might be surprised to learn that it is possible that even without anesthetic many teeth needing root canal treatment could be drilled on and you would feel no pain what so ever. In fact, it is conceivable that in some isolated cases (those where active infection and inflammation are not complicating factors) the entire root canal process could be completed without any anesthetic or pain. Why? Simply because in these cases the nerve tissue in the tooth has died, and dead nerve tissue cannot transmit pain sensations.

Should you expect that your root canal therapy can be performed without the use of an anesthetic? No, that’s not realistic. But if you are unequivocally anticipating that all root canal treatment results in an excruciatingly painful experience then someone has led you astray.

Will your dentist numb up your tooth prior to performing your root canal treatment?

Almost certainly, and especially if you ask them to. Nobody likes a bad time, not you, not your dentist. Just so things go as smoothly as possible and so there are no surprises, most dentists will go ahead and numb up any tooth on which they are performing root canal treatment.

Remember, your dentist is trying to perform treatment that will hopefully last you a lifetime. They need to be able to concentrate on their work and not on how you are reacting to it. By numbing up your tooth both of you will be more at ease and relaxed.

Root canal treatment is a “good thing.”

There are many reasons why a person should be eager to begin root canal treatment. In those cases where a person’s tooth has been the source of pain or swelling it is the root canal therapy that will initiate the process by which the painful or swollen tooth can be settled down. In some cases just those beginning steps a dentist takes as a part of performing root canal treatment can provide instant relief. Even in those cases where relief is not total the treatment should at least significantly reduce the pain, and also set the stage where the healing process can begin to take place much more rapidly than if root canal treatment had not been initiated.

Even if an episode of pain and swelling has not been experienced, a person should still be eager to initiate their root canal treatment. In the absence of pain and extensive infection the treatment will just go that much more smoothly. You will be relaxed and well rested. Your tooth will respond to the steps of the procedure more predictably. Additionally, any tooth that is in need of treatment, but has not yet received it, is unpredictable. Having your root canal treatment completed sooner rather than later reduces the chances that you will experience a painful tooth flare up (an acute tooth abscess).

What are the individual steps of root canal treatment?

A) Placing a rubber dam around your tooth.

After numbing your tooth but before beginning the actual process of performing the root canal treatment, your dentist will stretch a sheet of rubber around your tooth. Dentists call this sheet of rubber a “rubber dam.” It is held in place by a small clamp that grasps your tooth.

The purpose of a rubber dam is as follows. Since one of the fundamental goals of root canal therapy is to clean bacteria out of a tooth, and since saliva does have bacteria in it, the placement of a rubber dam allows the dentist to keep your tooth saliva free so it doesn’t get recontaminated with bacteria while your root canal treatment is being performed.

B) Gaining access to the nerve area of the tooth.

As a starting point for the process of performing your root canal treatment your dentist must first gain access to that area inside the tooth where the nerve tissue resides. This is accomplished by using a dental drill and making an access hole that extends down to the pulp chamber of the tooth. On posterior teeth this hole is made on the chewing surface of the tooth. On front teeth the access hole is made on the tooth’s backside.

C) Cleaning the tooth out.

The next step of the root canal treatment process is for your dentist to clean out the interior of your tooth (the pulp chamber and all root canals). As we discussed previously, this cleaning process removes any bacteria, toxins, nerve tissue, and related debris that are harbored inside your tooth.

For the most part the cleaning process is accomplished by way of using root canal files.” These objects look like straight pins but on closer inspection you would find that their surface is rough, not smooth. These instruments literally are files and are used as such. Your dentist will work a series of root canal files, each of increasing diameter, up and down in your tooth while simultaneously using a twisting motion. This action will scrape and scrub the sides of the tooth’s root canal(s), thus cleaning it out. Additionally, as part of the cleaning process your dentist will wash your tooth out periodically so to help flush away any debris that is present.

The goal is for your dentist to clean the entire length of the tooth’s root canal(s), but not beyond. As a means of determining the length of a canal your dentist may place a root canal file in your tooth and then take an x-ray. Once developed the x-ray picture will reveal if the file extends the full length of the canal or not. Alternatively, your dentist may have an electronic device that can make this same determination when it is touched to a file that has been positioned in a canal.

Traditionally the filing action of root canal files has been created by way of the dentist manipulating them with their fingers. There are, however, special dental drills (dental drills are called “handpieces”) which can hold and twist these files, and your dentist may choose to use one. As a variation on this same theme, there is yet another type of dental handpiece that produces a cleaning motion by way of holding a root canal file and vibrating it vigorously.

D) Placing the root canal filling material.

Once the tooth has been thoroughly cleaned your dentist can fill in and seal up its interior by way of placing root canal filling material. Sometimes a dentist will want to place the filling material the same day that they have cleaned the tooth out. Other times a dentist might feel that it is best to wait about a week before completing the root canal process. In the latter case your dentist will place a temporary filling in your tooth so to keep contaminates out during the time period between your appointments.

What root canal filling material is used?

The most common root canal filling material being used by dentists now days is a rubber compound called gutta percha. Gutta percha comes in preformed cones that are sized to match the files which have been used to clean out the inside of the tooth.

A root canal sealer (a paste) is usually used in conjunction with gutta percha cones. It is either applied to the cone’s surface before the cone is placed into the tooth’s root canal, or else applied inside the root canal itself before the gutta percha cone is positioned. Sometimes several cones of gutta percha need to be placed before the interior of the tooth has been filled adequately.

At times a dentist will warm the gutta percha cones (either before or after they are placed into the tooth) so they become softened. This allows the gutta percha to more closely adapt to the precise shape of the interior of the tooth.

As an alternative to the use of preformed cones, sometimes a dentist will place the gutta percha via the use of a gutta percha “gun.” This apparatus is somewhat similar to a hot glue gun. It warms a tube of gutta percha so the material is very soft. The gutta percha is then squeezed out into the tooth.

After your dentist has finished the filling and sealing aspect of the root canal process they will place a filling in the access hole they created at the beginning of your treatment. The individual steps of performing the root canal treatment have now been completed.

How long does root canal treatment take?

The total amount of appointment time that will be required for your root canal treatment can hinge on a number of factors. Some of these are:

• Different teeth have differing numbers of root canals, each of which need to be located, cleaned, and sealed. As an example, front teeth typically just have a single root canal while molars often have three or more canals.
• Will your root canal treatment be completed in just one sitting or will the process be broken up into two appointments? At times a dentist will feel it is best to clean out a tooth during an initial visit and then have you return for a second appointment when they will seal up the interior of your tooth. Equally common place, a dentist may feel that it is preferable to perform both tasks during the same appointment.

You will have to ask your dentist what amount of time is needed for your treatment. As a ballpark estimate however, it seems likely that any single appointment will probably last between 30 and 60 minutes.

What should be expected after root canal treatment?
Will there be any pain or discomfort after the root canal treatment?

The hope is that after your root canal treatment you will notice very little discomfort with your tooth. It can be common that for the first day or so after its treatment a tooth might feel a little tender. Whenever you have a question, in all cases, you should feel free to contact your dentist’s office just to ensure that what you are experiencing seems to them to be within normal limits.

A tooth’s sensitivity can often be minimized by using an over-the-counter analgesic, especially one that also possesses anti-inflammatory properties. Ibuprofen (Advil or Motrin) can be an effective choice for this type of discomfort. Of course you should always read the label, indications, and warnings of any product you anticipate using so to insure that it is an appropriate drug for you.

Should you chew on a tooth that has just had root canal treatment?

Don’t look for trouble. It is usually best to exercise caution with a tooth that is undergoing root canal treatment or has just had its treatment completed. Until your dentist tells you otherwise you should minimize chewing on the tooth. Here are some reasons why:

• In those cases where more than one root canal treatment appointment is needed the temporary filling that has been placed in your tooth might come out. If it does, saliva and debris will contaminate the interior of the tooth again. Your dentist will have to spend your next root canal appointment cleaning your tooth out a second time.
• Sometimes, since the tooth receiving the root canal treatment feels so much better, a person is eager to make use of their tooth again. Until your dentist has had a chance to finish rebuilding your tooth it should be considered to be fragile. What a disappointment it would be to spend the time, effort, and money to have root canal treatment performed, only to have the tooth break or crack irreparably before it was fully restored.

What additional dental work is needed for a tooth that has had root canal treatment?

After your tooth’s root canal treatment has been completed your dentist will need to discuss with you what additional dental work will be required so to make the tooth fully functional again.

Many times a tooth that has required root canal treatment is one that has a big filling or else has large portions missing due to decay or breakage. These teeth, in this state, are not as sturdy as they once were and for this reason it is commonplace that a dentist will recommend that a tooth that has had root canal treatment should be restored with either a dental crown or else a dental crown in combination with a dental post. Of course your dentist will need to determine what treatment is appropriate in your situation.

The dental restoration that is chosen for rebuilding a tooth that has had root canal treatment provides another function also. It provides a seal protecting the interior of the tooth. This barrier helps to prevent seepage of bacteria and contaminates from the oral cavity into the interior aspects of the tooth. Your dentist will need to advise you as to what they think is best for your situation but, in general, the sooner arrangements can be made to have the permanent dental restoration placed (thus creating the best possible seal) the better.

Placing a post in a tooth that has had root canal treatment.

A “post” is a rod that a dentist has positioned and then cemented in the canal space in a tooth’s root. Typically, but not always, dental posts are made out of metal.

Posts are usually only placed in those teeth which have extensive portions of their natural tooth structure missing. Dentists know, in general, that the greater the amount of a tooth that can extend up into the center of the dental crown, the more stable the crown will be. In those cases where a great deal of tooth structure is missing a dentist will “build up” the height of the tooth using dental filling material. A dental post provides a way for the dentist to securely anchor this filling material core to the tooth.

How does a dentist place a post in a tooth?

When placing a post a dentist will first use a drill and remove some of the gutta percha filling material that was placed during the tooth’s root canal treatment. They will then cement the post and subsequently place a core of filling material around the post’s upper portion, so to increase the overall amount of structure that will extend up into the crown.

Placing a dental crown on a tooth that has had root canal treatment.

Crowns are dental restorations that cup over the portion of a tooth that lies above the gum line. People sometimes refer to dental crowns as “caps.” Dental crowns can either be gold or else have a porcelain surface so they look white like a tooth’s neighboring teeth.

A dentist will use a dental crown as a means of improving the appearance of a tooth, restoring a broken tooth to its original shape, and/or strengthening a tooth. Additionally, and very importantly, dental crowns create an excellent seal over a tooth. By this we mean that a crown cemented in place provides a barrier that is helpful in preventing bacteria and contaminates from seeping back into those inner aspects of a tooth where the root canal treatment has been performed. After a tooth has had its root canal treatment completed, any or all of these qualities which a crown can provide may be needed.

What steps are needed to make a dental crown?

Before a dental crown can be placed the tooth must first be trimmed so it is tapered in shape. This tapered aspect of the tooth will extend up into the dental crown’s center and is a very important factor in the crown’s stability. After the needed shape has been achieved your dentist will take an impression of the tooth, which in turn is sent to a dental laboratory which will create the crown. Once the dental lab has completed your crown your dentist will cement it in place.