Endodontics is the study and treatment of the tooth pulp. Endodontic treatment can be carried out by general dentists or may be referred to an endodontic specialist for more complex cases. Conventional root canal treatment is the most common type of endodontic procedure and the focus of this article.

The two other major endodontic treatments are surgical root canal treatment (performed when a non-surgical root canal fails or is not enough to save the tooth) and retreatment (a follow-up procedure to a root canal treatment that is needed if the tooth doesn’t heal as expected).

What Is Root Canal Treatment?

Root canal treatment involves the removal of infected or inflamed pulp tissue. The pulp is the soft centre of the tooth located beneath the enamel and dentine. The pulp is made up of nerves, connective tissue and blood vessels that help the tooth grow. Damage to the pulp can be caused by deep decay or an injury to the tooth.

Root canal treatment, or root canal therapy as it’s also known, is recommended as a way of saving the tooth from extraction. This is achieved with the use of endodontic files and other endodontic accessories to shape, clean and fill the canal space.

Most root canal therapy is performed with the patient under a local anaesthetic.

Root Canal Access

To access the root canal, a small opening is made in the top of the tooth. This is normally done with a round bur or tapered bur attached to a high-speed dental handpiece.

For optimum efficiency and to maintain the structure of the tooth, attaining straight line access to the orifice and apex of the tooth is essential.

The orifice is the opening of the canal and the apex is the apical end point of the canal. Apex locators are often used to help identify the exact location of the apex.

A rubber dam should be securely placed around the tooth to prevent saliva or blood from leaking into the area being operating on.

The shape of the access point varies depending on the type of tooth being worked on. Below are the common choices of opening for the different tooth groups:

• Incisors – Triangular access
• Canines – Oval access
• Premolars – Oval access
• Upper molars – Rhomboidal access
• Lower molars – Trapezoidal access

How Many Root Canals Can a Tooth Have?

Different teeth have a different number of roots and a different number of canals. A particular tooth on one patient might have a different anatomy to the exact same tooth of another patient.

Below is a list of the most common anatomies for the different tooth groups:

• Incisors almost always have one canal in one root. Lower incisors occasionally have two canals
• Upper and lower canines almost always have once canal in one root
• Premolars can have either one or two roots and canals
• Majority of upper molars have three roots and often four canals
• Majority of lower molars have two roots and three canals, and occasionally four canals

Is Root Canal Treatment Painful?

Most conventional root canal treatment is carried out with the use of a local anaesthetic to numb the patient’s mouth and minimise the level of pain and discomfort felt.

Pain and discomfort levels can intensify during treatment as the anaesthetic wears off, but this will still usually only be mild. Root canal patients can experience moderate pain after treatment, but this should go away after two or three days. To minimise and reduce pain, patients should avoid eating hard foods immediately after treatment and can purchase over the counter pain relief.

How Long Does Root Canal Treatment Last?

Root canal treatment duration time depends on how many teeth need to be treated and the number of root canals that need to be cleaned. Treatment time can last from anywhere between 30 and 90 minutes depending on the case. According to the NHS, around 9 out of 10 root-treated teeth survive for 8 to 10 years. Having a crown fitted to the tooth is important for prolonging the tooth’s lifespan.