Roots and root canals: why a molar can have more than one.
An E-code can name one, two, three or four-plus canals. It sounds technical; the basic idea is more straightforward than it seems.
Updated 27 August 2026
First, the distinction: a root is not a canal
A root is the part of a tooth that sits in the jawbone. Inside it is a narrow space: the root canal. One tooth can have one root, several roots, or more than one canal inside the same root. That is why the number of roots and the number of canals do not always tell the same story.
For a root-canal treatment, the clinician assesses the canal system that needs treatment. That system can divide, join again or have smaller branches. Its shape differs from person to person, so variation is normal.
Why the pattern differs by tooth
Front teeth and canines often have a more straightforward internal pattern. Premolars and molars show more variation. A molar in particular has a larger internal landscape than its outer shape suggests. Images, examination and the clinical situation help build the right picture of one specific tooth.
Even teeth of the same type are not copies of each other. The available space can become narrower over time and canals can follow a different route from a textbook drawing. An illustration is therefore useful for understanding, not for predicting the anatomy of your own tooth.
How to read the E-codes
In the Dutch tariff structure, these code lines describe root-canal treatment per tooth, grouped by the number of canals:
- E13: treatment of a tooth with 1 canal;
- E14: treatment of a tooth with 2 canals;
- E16: treatment of a tooth with 3 canals;
- E17: treatment of a tooth with 4 or more canals.
The code identifies the tariff category of the work. By itself, it does not say how severe a problem is, how long an appointment will take, or which treatment is right for an individual. Other lines — such as an X-ray, anaesthesia or rubber-dam isolation — may appear beside the main code on an overview.
Useful questions when a proposal is discussed
- Which tooth is involved, and how many canals are included in this proposal?
- Which items appear beside the E-code, and why do they belong to this stage?
- Are any material, technical or other costs shown separately in the estimate?
- What happens after this stage, and when will the result be reviewed?
These questions do not reduce a technical term to a simple answer; they make it easier to discuss. Your practitioner can then explain the proposal in the context of your own tooth and images.
