Why do I need a root canal?
The short answer
Because the soft tissue inside your tooth (the “pulp”) is inflamed, infected, or has died, and it can't heal on its own. A root canal removes that tissue so you can keep the tooth instead of having it pulled.
Common reasons
- Deep decay that has reached, or come very close to, the nerve
- A crack or break that lets bacteria into the inside of the tooth
- An injury, such as a hit to the mouth. The nerve can die slowly, sometimes months or years later, even if the tooth looks fine.
- Repeated work on the same tooth, such as several large fillings over the years, which can wear on the nerve over time
- An old root canal that's having problems. Redoing it is called retreatment.
What a root canal actually does
The dentist makes a small opening in the top of the tooth, removes the damaged pulp, cleans and shapes the canals inside the roots, and seals them. The tooth stays in place and keeps working. Afterward, it usually needs a crown, especially on back teeth. See Do I need a crown after a root canal?
The tooth is numbed first, and most people find the procedure feels similar to getting a filling, though it takes longer. Some soreness for a few days afterward is common.
Who should do it?
Many general dentists do root canals, and some do a lot of them. A root canal specialist (an endodontist) does nothing but root canals and related care, every day.
Front teeth are usually the simplest, with one root and usually one canal. Back teeth have more roots and canals, which can be narrow or curved, so they take more time and skill. A specialist is a good choice for a back tooth, a tricky case, or if you're nervous about the treatment. If it isn't offered, it's fine to ask.
A specialist often costs more. See What should a root canal cost?
How your dentist decides
Your dentist puts together what you feel, what they see, and a few simple tests. Signs that often point to a root canal:
- Pain from hot or cold that lingers after the hot or cold is gone
- Pain when biting, or a tooth that throbs on its own, sometimes waking you up
- Swelling, or a small bump on the gum near the tooth
- A dark spot at the tip of the root on an X-ray
- No response when cold is placed on the tooth, or tenderness when it's tapped
Not every sensitive tooth needs one. If the nerve is only irritated, for example by a cavity that hasn't reached it, treating the cavity may be enough, and the sensitivity often settles down.
Teeth can also need a root canal without hurting at all. See I'm not in any pain. Why do I need a root canal?
What if I wait?
An infected or dead nerve won't heal on its own. The tooth may stay quiet for a while, but it can flare up with pain or swelling, and over time it may no longer be saveable. Here's what can happen if you skip it →
Questions to ask
- Can you show me on the X-ray what you're seeing?
- Which tests did you do, and what did they show?
- What's causing the problem with this tooth?
- Is there a chance a filling alone could fix this?
- Would you do this one, or would a specialist be a better fit?
- Does this tooth need a crown afterward?
- Before we schedule, can I get my cost in writing? (A predetermination if I'm using insurance, or a good faith estimate if I'm paying myself.)
When a second opinion makes sense
Reasonable if you have no symptoms and the X-ray finding is unclear, or if you're unsure whether the tooth is worth saving. An endodontist (a root canal specialist) is a good choice for a second look.