Cracked tooth: signs, what to do, and how it's fixed

What’s probably going on

A cracked tooth is often hard to pin down. The pain may come and go, show up only when you chew, and be tricky even for a dentist to trace to one tooth.

It hurts because chewing makes the cracked pieces move slightly. That irritates the pulp, the soft center of the tooth that holds its nerves and blood vessels.

Signs that often mean a crack:

• Sharp pain when you bite down, or when you let go. Pain as you release the bite is one of the clues.
• A twinge with hot, cold or sweet foods.
• Pain that comes and goes, rather than a steady ache.
• Swelling around one tooth.

Common causes include chewing ice, hard candy or popcorn kernels, grinding or clenching, a large filling, and injuries. A tooth that’s had a root canal but no crown is more likely to crack. So are teeth in people 50 and older.

The five kinds of cracks

The American Association of Endodontists sorts cracks into five types, from harmless to serious.

• Craze lines. Tiny cracks in the outer enamel only. They’re very common in adult teeth, don’t hurt, and are only a cosmetic concern.
• Fractured cusp. A piece of the chewing surface breaks off, often around a filling. It rarely reaches the pulp and usually doesn’t hurt much.
• Cracked tooth. A crack runs from the chewing surface down toward the root. Finding it early matters: once it extends below the gum line, the tooth can’t be saved.
• Split tooth. An untreated cracked tooth that has split into separate pieces. It can’t be saved whole, though sometimes part of it can.
• Vertical root fracture. A crack that starts in the root and works up toward the chewing surface. It often causes few symptoms, so it can go unnoticed until the gum and bone around it get infected.

A crack doesn’t heal the way a broken bone does. Left alone, a cracked tooth can become infected. See tooth abscess, and if biting is your main complaint, tooth hurts when biting.

What to do tonight

You can’t fix a crack at home. You can protect the tooth and calm the pain until you see a dentist, which should be as soon as you can get in.

1. Rinse with warm water. Swish and spit to clean the area. Warm salt water works too.
2. Cold pack on the cheek. It helps keep swelling down.
3. Take an over-the-counter pain reliever as the label directs. An anti-inflammatory such as ibuprofen or naproxen can ease pain and swelling. Ask a pharmacist first if you take other medicines, are pregnant, or have stomach, kidney or bleeding problems.
4. Chew on the other side. Every bite on the cracked tooth moves the pieces. Stick to soft foods until it’s checked.
5. Cover a sharp edge. If a piece broke off, dental wax from the pharmacy can cover the spot. Save the piece in milk if you can and bring it with you. Temporary filling kits aren’t made for broken teeth.

What not to do

• Don’t put aspirin on the tooth or gum. It can burn the gum tissue.
• Don’t keep biting on it to test it. Chewing moves the cracked pieces and irritates the pulp.
• Don’t wait for it to heal. Cracks don’t heal, and they can keep growing.

How a dentist fixes it, and what it costs

Cracks can be hard to find. A dentist may have you bite on a small stick, or shine a light through the tooth. A dye or X-rays can help too.

The fix depends on the type of crack and how deep it goes:

• Bonding. Tooth-colored resin fills in the crack.
• A new filling or crown. A fractured cusp usually gets a new filling or a crown. A crown is a cap over the tooth that can help keep the crack from spreading.
• Root canal. If the crack has reached the pulp, the damaged pulp is removed, and a crown usually goes on afterward.
• Extraction. If the crack runs below the gum line or the tooth has split, it may need to come out.

Once treated, most cracked teeth keep working for years. A crack can still grow or split after treatment, though, and that can mean losing the tooth later.

The price depends mostly on which of these you need. For a root canal, a molar usually costs more than a front tooth because it has more canals. Where you live matters too.

Pulling the tooth isn’t always the cheaper choice. A missing tooth usually needs an implant or bridge, and those tend to cost more, and take more visits, than a root canal.

Ask for a written estimate before any work starts. If you don’t have dental insurance, a dental savings plan (a discount membership, not insurance) can lower the price at participating dentists.

How to keep it from coming back

Most cracks come from pressure the tooth takes over and over.

• Don’t chew ice, unpopped popcorn kernels, hard candy, pens or your fingernails.
• If you grind or clench your teeth, ask your dentist about a night guard. See jaw and tooth pain from grinding.
• Wear a mouth guard for contact sports.
• If you have a large filling, or a tooth with a root canal and no crown, ask your dentist whether it needs more protection.
• See a dentist regularly, so a small crack gets caught before it splits.

If you grind at night, see the night guard pick below.