Root canal treatment is carried out using a rubber sheet (dam) around the tooth to ensure the tooth is kept dry during treatment, so there is no contamination from saliva. The dam also prevents you swallowing or breathing in any chemicals the dentist uses. Your dentist will open your tooth through the top of the tooth also known as the crown, to access the soft tissue at the centre of the tooth (pulp). They will then remove any infected pulp that remains.
If you have a dental abscess, which is a pus-filled swelling, your dentist will be able to drain it at the same time. After the pulp has been removed, your dentist will clean the root canal using files, these slowly enlarge the canal where the nerve was, making it easier to fill. The files used to enlarge the canals make them a regular shape so they can be filled. The treatment can take several visits.