Root Canal Treatment: What Happens and What to Expect Afterwards

Root Canal Treatment: What Happens and What to Expect Afterwards

14th October 2026

Root canal treatment worries a lot of people, often because of what they have heard rather than what they have experienced. It is a routine procedure that can save a tooth that would otherwise need to come out. This article explains why it is needed, what happens at each stage and what to expect afterwards, so you can go into your appointment knowing what is involved.

Reasons for treatment

Inside every tooth is the pulp, a soft core of nerves and blood vessels that runs down through narrow channels in the root. Those channels are the root canals. According to the NHS, the pulp can become infected through tooth decay, gum disease, a chipped or cracked tooth, or a dental abscess.

Once the pulp is infected it cannot heal by itself. Without treatment the infection can spread to the bone around the root, and the tooth may need to be taken out. Root canal treatment removes the infection and keeps the tooth.

Common warning signs

• Toothache, especially a throbbing pain or pain that wakes you at night.
• Sensitivity to hot or cold that lingers after the drink or food has gone.
• Pain when you bite or press on the tooth.
• Swelling in the gum or face, or a small spot on the gum near the tooth.
• A tooth that has turned darker than the teeth beside it.

Some infected teeth cause no pain at all and are only found on an X-ray at a routine check-up. That is one reason regular examinations matter.

Assessment and X-rays

Before recommending treatment, your dentist examines the tooth and takes X-rays to see the shape of the roots and whether infection has reached the bone. They may also test how the tooth responds to cold or to tapping. This tells us whether root canal treatment is likely to work, or whether the tooth is too badly damaged to save.

The treatment itself

You are usually given a local anaesthetic, so you stay awake but should not feel pain during the procedure. A thin rubber sheet, called a rubber dam, is normally placed around the tooth to keep it clean and dry. Then:

1. A small opening is made in the top of the tooth to reach the pulp.
2. The infected pulp is removed and any abscess is drained.
3. The canals are cleaned and shaped with fine instruments and disinfected.
4. The canals are filled and the tooth is sealed.

The NHS says treatment usually takes two or more appointments, each lasting about one to two hours or sometimes longer. Between visits you may have a temporary filling in the tooth.

Crowns after treatment

A tooth that has had root canal treatment has often lost a lot of its structure to decay, old fillings or the original injury. Back teeth in particular take heavy biting forces, so your dentist may recommend a crown to cover and protect the tooth once treatment is finished. We will explain whether you need one and why.

Recovery afterwards

Your jaw and face may stay numb for several hours. The NHS says the area may be swollen and sore afterwards, and this should improve within a couple of weeks. In the meantime:

• Take paracetamol or ibuprofen if you need to, following the instructions on the packet.
• Avoid chewing hard food on the tooth until the final filling or crown is in place.
• Keep brushing and cleaning between your teeth as normal.
• Contact us if the pain or swelling gets worse rather than better after a few days.

Our article How long does pain typically last after root canal treatment? covers recovery in more detail.

Retreatment of older root fillings

Occasionally a tooth that has had root canal treatment in the past becomes infected again, sometimes many years later. It can often be treated a second time by removing the old filling, cleaning the canals again and resealing the tooth. Our endodontics team carries out retreatment as well as first-time root canal work.

The alternative to treatment

The main alternative is taking the tooth out. That removes the infection, but it leaves a gap, and replacing a tooth with an implant, a bridge or a denture is usually more involved than keeping your own. We compare those options in Replacing a missing tooth: implant, bridge or denture?

Root canal treatment appointments

If you have toothache or have been told you may need root canal treatment, we can assess the tooth and explain your options. If treatment is needed, you will receive a written treatment plan with costs before anything starts. We also accept referrals from other dentists and from patients who refer themselves. Our current prices are on our fees page, and you can read more about the treatment on our root canal treatment page.

To book, contact us online or call the practice on 01625 599 001.