Why do I need a crown?
The short answer
A crown covers a tooth that's too weak or broken down to hold up on its own. The most common reasons are a large cavity or old filling, a crack or break, or a tooth that's had a root canal.
Common reasons
- A large cavity or a big old filling that leaves thin, weak walls
- A broken chewing corner (cusp) or a broken tooth
- A crack in the tooth
- A root canal. See Do I need a crown after a root canal?
- Replacing an old crown that has a problem. See My old crown doesn't bother me. Why replace it?
- Severe wear from grinding or acid (from foods, drinks, or reflux) that has worn a tooth down. Many plans don't pay for crowns on worn teeth. See how plans handle worn teeth.
- Holding a bridge or covering an implant
- Appearance: covering a badly stained or misshapen tooth. This is often cosmetic, and plans may not pay for it.
How your dentist decides
Your dentist looks at how much healthy tooth is left and where. A chewing corner that's broken or undermined matters more than a small cavity in the middle of the tooth.
Some of what they see won't be obvious on an X-ray. Cracks often don't show up on X-rays at all. Dentists find them with magnification, light, a bite test, or because the tooth hurts when you bite down or let go.
Cracked teeth
A cracked tooth may hurt now and then when you bite down or let go, or be sensitive to cold. Cracks can slowly grow. A crown holds the tooth together and gives it the best protection, though it can't guarantee that a crack won't keep growing. Tiny surface lines in the enamel (craze lines) are common and usually don't need a crown.
What if I wait?
A weak or cracked tooth often doesn't hurt, and it may hold up for a while. But it can also break without warning, sometimes in a way that can't be fixed, and then the tooth may need a root canal or have to come out. Here's what can happen if you skip it →
Seeing it for yourself
Ask to see the X-ray or a photo of the tooth. Many offices have a small camera that shows the tooth up close on a screen. It's often the quickest way to understand why a crown is recommended.
Questions to ask
- Can you show me the X-ray or a photo of what you're seeing?
- How much of the tooth is still healthy?
- Is there a crack? How did you find it?
- Would a filling or an onlay work for this tooth instead?
- Is this urgent, or can it wait a little?
- 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 can't see the problem on an X-ray or photo, if the tooth has only a small filling and no crack, or if several crowns are recommended at once with no symptoms.