Root Canal or Extraction: How to Decide

The choice in one line

When a tooth has a deep infection or badly inflamed nerve, there are two main routes. Root canal treatment cleans the infected tissue out of the tooth and seals it, so you keep the tooth. Extraction removes the tooth completely, and you then decide whether to replace it. Neither is right for everyone. The decision depends on what is left of the tooth, the bone and gum around it, and what you want from the tooth afterwards.

When saving the tooth is usually possible

A root canal is usually worth considering when:

• enough healthy tooth remains above the gum to hold a filling or crown
• the root is not cracked down its length
• the gum and bone around the tooth are firm
• the root canals can be reached and cleaned

Dentists generally prefer to keep a natural tooth where this is realistic. A natural tooth has a ligament around the root that lets you sense pressure, it keeps the neighbouring teeth in place, and it keeps the bone around it stimulated. Success rates for root canal treatment reported in studies are high, commonly more than 85 to 90 per cent, but they are not a promise for any one tooth. A tooth with a good seal and a well-made crown tends to do well.

When extraction is the more sensible choice

Extraction is often advised when:

• the tooth is broken below the gum line and cannot be rebuilt
• there is a vertical crack in the root
• the tooth is very loose because of advanced gum disease
• the tooth has already had treatment that failed, and re-treatment is unlikely to work
• the tooth is a wisdom tooth that is decayed, repeatedly infected or cannot be reached for cleaning

Cost, time and fear are valid factors too, but they should be weighed alongside the likely outcome, not instead of it. Treating a tooth that cannot realistically be saved can cost more over time than removing it.

What a root canal involves

Treatment is usually 1 to 3 visits of 45 to 90 minutes under local anaesthetic. The dentist removes the infected pulp, cleans and shapes the canals, and fills them. A crown is often advised afterwards, especially on back teeth, because a tooth without its nerve can become brittle. You can read the steps in root canal treatment, and what to expect afterwards in root canal aftercare.

Mild soreness for 2 to 5 days is common. If the tooth later becomes painful or swollen again, it can sometimes be re-treated.

What an extraction involves

A simple extraction takes about 20 to 40 minutes, longer if the tooth is broken or impacted. The area is numbed, and you will feel pressure but not sharp pain. A surgical extraction, for example of a wisdom tooth, may need a small cut in the gum and a few stitches. The socket heals over 1 to 2 weeks, and the bone remodels over several months. See oral surgery for more.

What happens if you leave the gap

Many people are told that a gap at the back "doesn't show", and so leave it. Over months to years, though, this can lead to:

• neighbouring teeth tilting into the space
• the tooth above or below drifting down or up
• food trapping, which increases decay and gum problems
• more chewing load on the remaining teeth
• gradual loss of bone where the tooth was

Not every gap causes trouble, and it is reasonable to wait in some cases, but it should be a decision you make with your dentist, not by default.

Replacing an extracted tooth

The usual choices are a dental implant, a bridge or a removable partial denture. An implant is a titanium post placed in the bone, and it avoids filing down neighbouring teeth. A bridge is faster but depends on those neighbours. A partial denture is the least invasive and usually needs the least time. Which one fits depends on bone, gums, bite, health and budget. See dental implants and how long dental implants last.

Questions to ask

1. Can this tooth be restored with a filling or crown after treatment?
2. What is the realistic chance of success, and what lowers it?
3. If I extract, what are my replacement options and when can they be done?
4. What happens if I wait?
5. What is the total treatment, not just the first step?

Asking for the whole plan, with each stage, is the easiest way to compare the two routes fairly.