Root canal: what happens inside, and how much it hurts

When is it needed?

The soft inner part of a tooth holds the nerve. Deep decay, a broken or cracked tooth, or an abscess can infect it. When decay reaches the nerve, pus can collect at the root. Without treatment, the tooth often has to come out.

Signs to get checked

• Tooth pain, especially when chewing.
• Sensitivity to hot or cold that lasts a long time.
• Swollen gum beside the tooth, or a boil on the gum.

These signs don't always mean a root canal. The dentist decides after an examination and, if needed, an X-ray. If it hurts, don't wait.

How much does it hurt?

The tooth is numbed first, so it usually doesn't hurt. Once the numbness wears off, mild pain or swelling can last a few days and then settles.

How many visits does it take?

It is finished in one or more visits, depending on the infection and how many canals the tooth has. Between visits the tooth may have a temporary filling.

What happens, step by step

1. The tooth is numbedWith local anaesthesia it usually doesn't hurt.
2. The infected nerve is removedA small opening is made in the top of the tooth to take out the nerve.
3. The canal is cleanedFine files and disinfectant clean the inside.
4. The canal is filledIt is filled with a special material and sealed on top.
5. A cap goes on topIn many cases a cap is needed to keep the tooth strong.

What to do after treatment

• Don't eat while you are numb, because you could bite your cheek or lip.
• Avoid chewing anything hard on that tooth until treatment is finished.
• If you need a painkiller, take it as your dentist advises.
• Come to your next visit, and have any cap done on time.
• Keep brushing regularly and come for check-ups.

When to contact us quickly

• Pain or swelling is getting worse instead of better.
• The temporary filling has fallen out.
• Your face is swelling or you have a fever.

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