Root canal treatment saves a tooth that is heavily damaged or decayed. Often used as a last resort, root canal treatment involves removing the living portion of a tooth - the pulp - then cleaning and filling the canal that it occupied. Finally, a filling or restoration is placed on the tooth surface to block access to the treated canal.

Anatomy of a tooth

To better understand root canal treatment, you need to have a brief understanding of tooth anatomy. Inside the tooth, under the white enamel and a hard layer called the dentin, is a soft tissue called the pulp. The pulp contains blood vessels, nerves, tissue and creates the surrounding hard tissues of the tooth during development. However, once a tooth has fully matured, it can survive without the pulp.

Why remove the pulp?

A tooth's pulp may need to be removed for various reasons, but the most common are tooth decay, trauma, or tooth sensitivity. Tooth decay, if left untreated, can advance past the outer shell of the tooth and reach the pulp. Since the pulp contains the tooth's blood vessels and nerves, bacterial infection can cause the pulp to become inflamed and irritated. This can in turn cause toothaches, and if left untreated, an abscess can form. An abscess is a pus-filled pocket that forms at the end of the roots of the tooth. Bone is lost around the tooth, swelling begins, and the tooth, and perhaps surrounding teeth, will need to be pulled or extracted. A root canal can stop this cascade of bad events by removing the pulp material, cleaning the chamber, and stopping the infection before it spreads.

Trauma to a tooth can behave the same way as an infection. If a tooth is damaged in an accident, the pulp may become irreversibly inflamed, causing pain. Root canal treatment can remove this pain since removing the pulp also removes the nerves that allow the tooth to feel pain. Similarly, patients who have tooth sensitivity to hot or cold, and have tried other ways to control their symptoms, may have to resort to root canal treatments. Removing the pulp has the effect of removing the nerves which conduct cold/hot sensation from the tooth. Remember, following root canal treatment, a tooth is essentially dead and cannot feel anything - the tooth can still function fully in everyday use though.

Who needs root canal treatment? Who does not?

As stated earlier, any tooth which has an inflamed or infected pulp, may need root canal treatment. If you have pain on biting, prolonged sensitivity to heat or cold, tenderness to touch and chewing, discoloration of the tooth, and swelling, drainage and tenderness in nearby gingival tissues, you may require a root canal. Sometimes, however, there are no symptoms, and a root canal may still be needed. By running various tests, your dentist will be better able to make a recommendation.

In certain cases, an inflamed pulp can return to normal as long as the infection has not reached the pulp. As bacteria make their way to the pulp, the pulp becomes inflamed before the bacteria has even entered the pulp canal. If the decay is removed and repaired, the pulp may reverse itself and no longer be inflamed. If the infection has reached the pulp canal though, root canal treatment is almost always required. Always ensure that your dentist has done everything possible to avoid doing a root canal treatment - because of how extensive and costly it is, root canal treatment should always be a last resort.

Finally, there are few cases where a child should get root canal treatment on primary teeth. Since these teeth will fall out eventually anyways, it is not a common procedure, but still required in particular cases. Root canal treatment of wisdom teeth is never required - they should just be pulled.

In certain cases, your dentist may want to do a root canal treatment, but it is not possible. If the infection has gone too far and for too long, removing the pulp may no longer help the tooth since the infection has spread past the tooth in question. Other times, the root of the teeth may bend at such sharp angles that removing the pulp becomes impossible. An endodontic specialist may be able to perform the treatment though - ask your dentist about getting a referral.

Dental Procedure

Most root canal treatments take 1 to 2 appointments to complete, but might require more time if a crown or cap is being placed on afterwards. 1) To begin, your dentist will analyze x-rays to have an understanding of the tooth's root structure, and will begin the procedure by administering local anesthetic. Following this, a root canal should be essentially painless since all nerves leading to the tooth are now blocked.

The tooth is isolated using a "dental or rubber dam" to prevent your saliva or other contaminants from gaining easy access to the tooth. 2) Using various drills, your dentist will then make an opening in the tooth from the top and slowly drill downwards towards the pulp chamber opening. 3) Once the chamber has been accessed, your dentist will remove the nerves and blood vessels, or pulp, and begin cleaning and shaping the empty canal.

Various electronic locating devices, along with the use of x-rays, guide the dentist so that the drill never extends past the tooth apex. 4) After the space is cleaned and shaped, the root canal is filled with a biocompatible material, usually a rubber-like material called “gutta-percha.” The gutta-percha is placed with an adhesive cement to ensure complete sealing of the root canals. This ensures that bacteria cannot gain easy access in the future.

Depending on how severe the case is, your dentist may opt to not fill the canal with gutta-percha on the first appointment. Instead, he or she may place medication material within the canal, temporary seal the top portion of the tooth, and give the antibiotic medication some time to work. Then in the next appointment, when the canal is clear of bacteria, the canal will be filled and sealed.

X-rays showing the pre and post treatment results. Note the third tooth and how its roots appear opaqe white in the "after" photo. This is the result of the filling material which is placed in the cleaned out canals nearing the end of the treatment process.

In either case, once the root canal has been sealed, the crown of the tooth (top portion) is ready to be restored. Your dentist may place a simple filling if the cavity made is small, or may place a temporary filling if the tooth requires a crown or cap at a later date.

Pain Expectations

Many endodontic procedures are performed to relieve the pain of toothaches caused by pulp inflammation or infection. With the use of anesthetics, most patients report that they are comfortable during the procedure.

For the first few days after treatment, your tooth may feel sensitive, especially if there was pain or infection before the procedure. This discomfort can be relieved with over-the-counter or prescription medications - inform your dentist if you are sensitive to even minor pain.

Your tooth may continue to feel slightly different from your other teeth for some time after your endodontic treatment is completed. However, if you have severe pain or pressure or pain that lasts more than a few days, call your dentist.

In very rare cases, the tooth might be receiving accessory nerves from other areas of the mouth. Under those circumstances, your dentist may think he has anesthetized the right nerves, but upon drilling, pain is felt. Another injection or "block" is enough to remove all remaining sensation to the tooth - but that initial pain sensation is probably where the fear of root canal treatments derives from. Be assured that this is very rare, and almost all patients have little to no pain during the procedure.

Post Treatment Care

Following treatment, try to avoid chewing or biting hard on the treated tooth until it has been fully restored by your dentist. An unrestored tooth is susceptible to fracture, so you should see your dentist for a full restoration as soon as possible. Practice good oral hygiene, including brushing, flossing, and regular checkups and cleanings, as normal.

Success Rate & Complications

Extensive studies have shown that root canal treatments are highly successful; the procedure has more than a 95% success rate. Many teeth fixed with a root canal can last a lifetime. The success of the treatment depends on how well it is performed by your dentist, and how extensive the damage was to begin with; heavily decayed teeth have lower success rates.

Despite your dentist's best efforts, new infections might emerge following treatment though. Among the likely reasons for this include:

• Your dentist missed a canal and left one untreated (certain teeth can have 4 or more canals)
  
• Undetected crack in the root of the tooth which allows bacteria in from the side
  
• Poor dental restoration which allows bacteria to gain access to the root canal chamber
  
• A breakdown of the inner sealing material over time, allowing bacteria to recontaminate the inner aspects of the tooth

Sometimes retreatment can be successful, other times endodontic surgery must be tried in order to save the tooth. The most common endodontic surgical procedure is an apicoectomy or root-end resection. This procedure relieves the inflammation or infection in the bony area around the end of your tooth that continues after endodontic treatment. In this procedure, the gum tissue is opened, the infected tissue is removed, and sometimes the very end of the root is removed. A small filling may be placed to seal the root canal.

Advantages & Disadvantages

The tooth remains in your mouth, pain free, following root canal treatment. Although the cost of the therapy is significant, replacing the tooth with fixed or removable prosthesis (bridges) usually costs more than the root canal therapy.

Unfortunately, there is a necessary time involvement to accomplish root canal therapy (one or more appoints). Also, the cost is significant, but well worth it to keep your own natural teeth.

Cost

Root canal therapy costs vary significantly. The fee for a root canal for a single-rooted tooth costs much more than removal of the tooth. A single-rooted tooth (front teeth for example) can cost around $500 for treatment, while molars can cost around $700 because of the additional roots they have (molars most often have 3 or more roots). There is usually an additional cost if the tooth requires a post, and if a crown (cap) is needed there is a further cost.

Alternative Therapies