The tooth consists of several layers.

The outermost layer is known as the enamel and it is like a shield which protects the tooth from all kinds of exterior impacts. Underneath the enamel layer there is a structure called dentin.

Under the outer layers of the tooth (enamel and dentin), a soft connective tissue, the dental pulp is found which forms the vital part of the tooth. This layer is commonly known as the "nerve of the tooth".

The pulp is located in a small chamber housing the nerves and the blood vessels. This small chamber is transformed to canals at the roots of the tooth and stretches out to the root tips. That's why the treatment of the pulp tissue is called "root canal treatment". Tooth canals are tiny and thin tunnels that commence from the crown and reach out until the root tips. The nerves and the blood vessels within the root canals open up to the alveolar bone through almost invisibly small holes.

Root canal therapy is the procedure of removing the pulp which has been infected due to various reasons and then disinfecting and placing artificial tissue-friendly materials into the empty canals.

During recent years, in order to relieve the patient with an infected pulp from pain the only thing to do was to extract the tooth. But today, thanks to root canal therapy the teeth can be kept in place providing function for many years.

While the pulp doesn’t have an ability to heal itself, it dies when it is damaged and inflamed.

The damage, inflammation and death of a pulp is most frequently observed in case of:

- A cracked tooth or a tooth which has suffered trauma
Or
- In case of a deep caries which hasn’t been treated and penetrated until the pulp

In both cases, the bacteria reach the pulp and cause an inflammation, afterwards chewing, pressure or any kind of hot, cold stimulants cause extreme sensitivity and pain. Apart from this, the inflamed pulp also leads to spontaneous pain which can’t be cured with painkillers. If you observe a tooth pain which isn’t related with a hot, cold exterior stimulant or a pain which starts on its own, then there is possibly an inflammation of the tooth nerves.

When a tooth starts to decay, first the outermost enamel layer wears off. As the enamel layer doesn’t contain any nerve tissues, no pain is observed at this phase. But when the caries isn’t treated, it penetrates into the deeper areas and reaches the dentin tissue. As the dentin tissue is adjacent to the tooth nerves within the pulp chamber; cold, hot, sugary stimulants cause pain at this phase.

No matter from which location it starts, the caries first erodes the enamel, then the dentin layer and afterwards advances to the pulp

If at this phase the caries is not treated properly, it continues to advance reaching the pulp at its final phase. The nerves of the tooth are infected due to the bacteria within the caries and an inflammation commences. At this stage, the pain starts on its own, no cold, hot or sugary stimulants are needed. The pain starts spontaneously and is very strong making the person suffer tremendously. In some cases painkillers are insufficient.

While it is possible to treat the decays of the enamel and dentin layer with simple fillings, in cases where the caries has reached the nerves, fillings are not an adequate solution anymore. A root canal therapy is necessary in order to remove the inflammated nerve tissue and replace it with artificial canal fillings. Root canal therapy is in a sense the mummification procedure of the tooth. As a result of the root canal therapy the tooth has been cleaned of its nerves, it is lifeless, but it can still maintain its function in chewing hard substances.

Supposing that the pulpal inflammation isn’t treated with a root canal therapy, inflammation filled sacs start to form at the root tips and the alveolar bone and these are called abscess. These abscesses which develop at the root tips widen and cause a destruction at the bone structure surrounding the root.

The radiograph of a tooth with root canal therapy
The dark colored areas around the root tip result from the bone loss due to the abscesses

How is root canal therapy performed?

If the nerves of the tooth are no more vital due to inflammation, the root canal therapy follows a completely painless sequence. But if the vitality of the pulpal nerves are still in question, then the first step is to apply a local anesthetic so that the pain is prevented, afterwards the caries is removed and the tooth is perforated from the crown part in order to reach the pulp.

The infected blood vessels and nerves are removed, then the canal is cleaned and enlarged using a series of files. The canal will then be disinfected, any remaining bacteria will be killed and a well fitted, tissue-friendly filling will be inserted.

A root canal therapy can last approximately 2-3 visits according to the condition of the tooth.

Especially if the tooth isn’t vital and there is a root tip inflammation, the dentist will use some medications to get rid of the bacteria. So that these medications can act on the bacteria, the tooth will be sealed with temporary fillings. In case of severe inflammation, oral antibiotics may be used.

After the treatment has been completed, you might observe minor pain and sensitivity complaints, the pain might increase under pressure, but these are all temporary problems. In these cases, the best solution is not to use that part for a couple of days, afterwards it will be observed that the sensitivity completely diminishes.

After the disinfection of the pulp, and the clearance of the infection problem; first the canal is filled permanently then the lost tooth tissue is restored. Based on the amount of the lost tooth tissue and the shape of the substantial walls, either a filling or a ceramic crown is applied.

If the substantial tissue isn’t sufficient enough to support a crown, then a pin is placed into the canal and post core application is carried out.

Post Core application on a molar tooth

A tooth with root canal therapy can be kept in the mouth for many years just like a completely healthy tooth if good oral hygiene is practiced.

The information contained in the site is to inform about dentistry and treatment methods.
This information is definitely not a substitute for the physician to examine the patient for medical purposes or to make a diagnosis.