Root canal treatment: when is it needed, how many visits, does it hurt?
Root canal treatment cleans out a nerve (pulp) inflamed by decay or trauma, disinfects the canals and seals them. It's done under local anaesthetic, usually takes 1–2 visits, and aims to keep the tooth rather than extract it.
Symptoms that may mean you need a root canal
- Pain after hot or cold that lingers
- Spontaneous, throbbing pain that wakes you at night
- Tenderness when biting or touching the tooth
- Swelling of the gum or a pimple-like bump that discharges
- Darkening of the tooth (especially after an injury)
Sometimes a nerve dies without any symptoms and is found on a routine X-ray, which is why regular check-ups matter.
How is root canal treatment done?
- X-rays show the number and length of roots and the extent of infection.
- Local anaesthetic is given and the tooth is isolated.
- Decay is removed and the nerve tissue is reached.
- The canals are cleaned and shaped with special instruments and rinsed with disinfecting solutions.
- The canals are filled with a sealing material.
- The tooth is restored with a permanent filling or crown.
How many visits does it take?
| Situation | Typical visits |
|---|---|
| Vital but inflamed nerve | Usually one |
| Dead nerve with infection at the root (abscess) | Usually two, with medication placed in between |
| Redoing a previous root canal | Two or more |
A visit usually lasts 45–90 minutes. Front teeth have fewer canals and take less time; molars take longer.
Does root canal treatment hurt?
It's done under local anaesthetic and most patients feel no significant pain during treatment. In fact, it relieves the pain caused by the inflammation. Mild tenderness when biting for a few days afterwards is common and usually settles with simple painkillers.
Do I need a crown after a root canal?
Root-filled teeth, especially back teeth, are more prone to fracture because of lost tooth structure, so a crown is often recommended for molars. Front teeth or teeth with little tissue loss may only need a filling. See types of dental crowns.
Isn't extraction simpler?
Extraction can look quicker in the short term, but the missing tooth then needs replacing with an implant or bridge, which takes longer and costs more. Keeping the natural tooth is usually the first choice when possible. If a tooth has been lost, see implant or bridge. You can also read more in our treatments section.
Frequently asked questions
Can a root canal be done in one visit?
If the nerve is still vital and there's no infection at the root, often yes. With an abscess, it's usually completed in two visits.
How long does pain last after a root canal?
Mild tenderness usually fades over 2–5 days. Increasing pain or swelling should be checked.
How long does a root-filled tooth last?
A well-treated and properly restored root-filled tooth can last many years, often for life.
Can I have a root canal while pregnant?
Yes, when needed; the second trimester is usually the most comfortable time. X-rays and medication are planned with your pregnancy in mind.
