Root Canal Therapy (Endodontics)

Endodontics (Root Canal Therapy)

More often than not, the most scary and mystical dental procedure according to our patients is root canal therapy. We would like to summarize the endodontic treatment procedure briefly here to address the curiosity about root canal therapy and soothe potential concerns.

Tooth anatomy

In order to comprehend root canal therapy, first we need to have a basic understanding of tooth anatomy.

Upper part of tooth, the bone part visible above the gum, is called ‘crown’; on the other end, the lower part, which is not visible as it is inside the jawbone, is called ‘root’. A tooth also is made of layers like our bones. Outer layer, the part visible above gum line, is called ‘enamel’. Enamel is the hardest and most mineralized part of our body. Under gum line, ‘cement’ covers root surface. Under enamel and cement layers is a formation called ‘dentine’. While almost as hard as bone, dentine contains nerve ends, unlike enamel.

The layer under dentine is called ‘dental pulp’, and consists of large and tiny blood vessels, connective tissue, nerve fibrils, and a variety of cells. Pulp’s mission is to feed the tooth during growth and development. Once a tooth is fully developed, pulp is demoted down to a pain transmitter if/when tooth is damaged or infected.

Sometimes pulp can be infected. In such cases, pulp may need to be removed by root canal therapy. Canal treatment is the only way to keep an infected tooth in your mouth. A fully developed tooth can keep functioning without a pulp.

How is dental pulp infected?

Most common reason of pulp infection is untreated cavities. Every person has a certain amount of bacteria in their mouths, and these are not harmful under normal conditions. However, some of these bacteria metabolize (tear down) food or drink with carbohydrates (sugar) and produce acid. This acid is harmful to enamel and dentine. When a tooth decay formed this way is untreated, bacteria advance their way through dentine to pulp (nerve) tissue to expose and infect it.

Pulp can also be infected after a trauma on tooth. A strong blow on tooth may prevent blood flow into tooth through jawbone, which causes pulp tissue to wither away. Interesting point: if there’s a crack on enamel or dentine layers, root canal treatment requirement may in fact be lower. That crack would push on blood flow towards the tooth and help absorb trauma.

Another way to get pulp infection is having a long-term periodontal disease around tooth. Bacteria may find their way through infected tooth into the dental pulp via tiny canals on root surface, and cause what we call ‘retrograde infection’.

Regardless of cause, infected pulp tissue will wither away, and may cause a painful abscess around jawbone.

How can I tell if a tooth is infected?

If your tooth suffers from long-term hot/cold sensitivity or biting causes pain, we may consider tooth infection.

At the same time, a significant colour change or a swelling in surrounding gum tissue, even when there is no pain, can be sign of a dental infection.

Sometimes, without any of these symptoms, dental and radiographic examinations may reveal findings that require a root-canal treatment, too.

How much antibiotics are required to treat tooth infection?

When a tooth is infected, we would consider root canal therapy, or in severely damaged cases, extraction. A dead pulp makes the tooth an ideal environment for bacteria growth. When necessary, your dentist may prescribe you antibiotics to strengthen your immune system and fight the infection.

Under normal circumstances, you don’t need to use antibiotics during root canal treatment.

Will I feel pain during and after root canal treatment?

Root canal therapy requires patience and devotion by both the patient and dentist. Dentist’s most important responsibility is to make them as comfortable as possible and spare them from feeling pain. For this reason, dentist may apply anaesthetics around the infected tooth before operation, if they deem necessary. This numbness will prevent patient from feeling any pain, and procedure is completed rather quickly.

Do all teeth have same number of roots?

Incisor and canine teeth at front part of mouth have 1 root and 1 canal inside that root, while premolar on sides of the mouth generally have 2 roots, and 1 or 2 canals. Upper jaw molars generally have 3 roots and 3 or 4 canals, and finally lower jaw molars have 2 roots and 3 or 4 canals.

All these numbers are generalizations. In specific cases, extra roots and/or canals may be commonly encountered.

What are the stages of root canal treatment?

1. Local anaesthesia: numbing tooth and surrounding tissue.

2. Cleaning decay in cavity, if any, and clearing root canals.
3. Determining canal length by radiography (x-ray).
4. Taking out and cleaning the root (pulp) inside the root canal.
5. Shaping root canals with various tools and devices.
6. Disinfecting root canal from microorganisms.
7. Filling up root canals.

The purpose of filling up root canals is to hermetically replace the canal gap left after pulp to create a barrier against microorganisms and tissue liquids. This way, tooth can continue to stand despite being lifeless.

Will there be any pain after canal treatment?

There may be minor pain and sensitivity after the treatment, but it will be temporary. Best solution in this case is to avoid that side of the mouth for a couple of days. In a short while, the sensitivity will disappear.

How can I tell if root canal treatment was unsuccessful?

Success rate for accurately applied root canal therapy is around 90-95%. If there is any pulp tissue left in root during treatment (which may be caused by skipping a root during treatment), or if root filling is improper to allow microorganisms in, if tooth is damaged by perforation or similar mistake, or cracks have formed between roots, root canal treatment may be unsuccessful. In most cases, you will feel pain when biting after an unsuccessful canal therapy.

What should I do after an unsuccessful canal treatment?

Mostly canal treatment is repeated, and mistakes, if any, are corrected. Previous canal filling is removed, tooth canal is reshaped and cleaned again to be filled up. If even after this repeated procedure no results is achieved, a surgical procedure called ‘apical resection’ will be performed. In this operation, surgeon reaches tooth root, surgically cleans the root and surrounding area, and closes and stitches the tissue. If even this surgical procedure isn’t enough, that tooth may have to be extracted.