Dental guide
What actually happens during root canal treatment?
A plain explanation of why root canal treatment is done, what the appointments involve, and what recovery usually feels like.
Draft. This guide is not yet approved clinical advice. It awaits review by a named clinician before it can appear on the clinic's official website. It draws on UK (NHS and NICE) guidance; the reviewer will also check how that guidance applies under local requirements and practice.
What this means for you
- Root canal treatment aims to save a tooth whose inner pulp is infected or badly damaged.
- It is done under local anaesthetic and often takes two or more appointments; a crown may follow.
- The main alternative is removing the tooth, so ask about the prospects of each option.
Being told you need root canal treatment can sound alarming. Knowing what the treatment is for, and what happens at each stage, often makes it much easier to face.
What it is for
Inside every tooth is soft tissue called the pulp. If the pulp becomes infected, for example through deep decay, a crack, gum disease or an abscess, the infection can cause pain and spread. Root canal treatment removes the infection from inside the tooth, then cleans and seals it so that it is less likely to become infected again. The main alternative is usually removing the tooth.
What happens during treatment
The NHS describes the treatment in broad steps:
- A local anaesthetic numbs the tooth. You stay awake.
- A small opening is made in the tooth to reach the pulp.
- The infected pulp is removed and the inside of the tooth is cleaned and shaped.
- The tooth is sealed with a filling.
It commonly takes two or more appointments, which may each last one to two hours, or sometimes longer. If the tooth was badly damaged, your dentist may recommend a crown afterwards to protect it.
Afterwards
It is normal for the area to feel numb for a few hours, and for the tooth and gum to feel sore or a little swollen for a while; the NHS says this should improve within a couple of weeks. Your dentist will tell you which pain relief is suitable for you and how to look after the tooth until treatment is complete.
Contact your dentist if pain or swelling gets worse rather than better, or if you develop a high temperature.
Questions you might ask
- Why do you recommend root canal treatment for this tooth, and what are the alternatives?
- How many visits do you expect, and will I need a crown?
- What will the complete course of treatment cost?
Sources
- NHS: Root canal treatment (page last reviewed 3 October 2025; checked 26 September 2026)
General information, not a diagnosis. This guide can't take your individual circumstances into account. Please speak to a dentist about your own situation.