Root Canals: Know the Anatomy for Root Canal Treatment


Root canal overview

Before knowing root canals, get some idea about the tooth anatomy. A tooth is made up of two portion that is tooth crown and tooth root. Tooth crown has outer hard and strong layer called as Tooth Enamel. Below the enamel, there is a layer of Dentin. Below the dentin, there is pulp chamber. Pulp chamber is consist of pulp tissue that provides vitality to the tooth. These pulp tissues are extended from pulp chamber to the root canals in the tooth root. In the root canals where pulp tissue ends, there is a hole at the root tip, known as Root Canal Orifices.

So, now let’s get some information about what is root canal? And why is it important for root canal treatment?

What is root canal?

As said, the Root canal is one of the anatomies of the tooth. It is the part of the tooth roots. The root canal is the portion of the tooth starts from the base of the pulp chamber to the root canal orifices.

Root canal anatomy

Root canals are mainly divided into three parts. They are:

  • Coronal
  • Middle
  • Apical

The apical portion of the root canal consists of lateral branching. These are called as Accessory or Lateral Canals.

The root canal has an open end at the root tip from where the blood vessels and nerves enter into the tooth root. This open end is known as Apical Foramina. Apical foramina is the main opening of the root canal. Same way, accessory or lateral canals have also open ends. These open ends are called as Accessory Foramina.

It is said that root canals are never been straight. They may show constrictions or some degree of curvature mainly in the apical third of the root. This curvature can be a smooth curvature of an entire root canal or it can be straight till the apical third of root canal and then there is a sharp curvature.

Number of root canals in the tooth

Every tooth has anatomic variation and so some teeth have single root canals, some have two root canals and some have more than two root canals present. Mostly it depends on the number of roots present in the tooth. But it is not true every time.

Root canals present in upper teeth

  • Upper Incisors: one root canal
  • Upper Canine: one root canal
  • Upper first premolars: two root canals
  • Upper second premolars: one or two root canals
  • Upper molars: there, four or more root canals

Root canals present in lower teeth

  • Lower Incisors: one or two root canal
  • Lower Canine: one root canal
  • Lower first premolars: one or two root canals
  • Lower second premolars: one or two root canals
  • Lower molars: there, four or more root canals

(Source: Grossman’s Endodontic Practice, Twelfth Edition)

Curvature of root canals and root canal treatment relation

The curvature of a root canal is basically termed as the shape of the root canal. The shape of the root canal is the main focus for root canal treatment. As we know when the tooth gets infected, it requires root canal treatment to save the tooth. Now, when the tooth gets infected, we need to remove the pulp tissue from the pulp chamber and root canals. Pulp chamber is the wide area that can be cleaned easily by removing pulp tissues with the help of the drills. But, root canals are very narrow and curvy so these cannot be cleaned by using drills. It must be cleaned by files.

Why root canals are the most important part of root canal treatment?

The answer is, due to curvature or shape of the teeth, files sometimes cannot reach the all infected areas in the canals and if the bacteria or other pathogens still there in the canals even after root canal treatment then there is a chance of secondary infection and root canal treatment fails.

Now here the success rate of root canal treatment depends on:

  • Degree of curvature present
  • Flexibility of the files used during root canal treatment
  • Skill of the dentist or endodontist


For better success rate of root canal treatment your doctor or endodontist must be aware of the proper knowledge of root canals anatomy.

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