Pain after a root canal: what's normal and what isn't

What’s probably going on

A root canal removes the inflamed or infected tissue from inside the tooth. The tissue around the root can stay irritated for a little while after, even when the treatment went well.

What’s normal, according to the American Association of Endodontists (AAE):

• Tenderness for a few days. Most people have mild discomfort that improves within three to five days.
• Soreness when you bite or touch the tooth. This is common while the area heals.
• A sore jaw. The AAE says mild jaw soreness is normal and usually fades within days.
• Less pain than before. For most people, the root canal takes away the pain that sent them in.

Cleveland Clinic says most people recover in less than a week. Pain that lasts past that, or gets worse, isn’t the usual pattern.

When pain doesn’t settle, or comes back later, common reasons include:

• An uneven bite. If the tooth hits first when you close, the AAE lists that as a reason to call.
• A canal that wasn’t found or fully cleaned. Narrow, curved or extra canals can be hard to see the first time.
• A leak. A temporary filling that wears away, or a crown that’s loose or cracked, can let bacteria back in.
• A small crack. The AAE says tiny fractures can go undetected on X-rays during the first treatment. See cracked tooth.
• New decay that reaches the root canal filling, sometimes years later.

What to do tonight

For normal soreness in the first few days:

1. Take an over-the-counter pain reliever as the label directs. The AAE says ibuprofen or acetaminophen is often enough. Ask a pharmacist first if you take other medicines, are pregnant, or have stomach, kidney or bleeding problems.
2. Use a cold pack on the cheek for short stretches. The AAE says it can help keep swelling down. Never use heat on a swollen face.
3. Chew on the other side. Avoid hard foods and heavy biting on the treated tooth until it has its permanent filling or crown.
4. Take any prescription exactly as written, if your dentist gave you one.
5. Call if the temporary filling comes out. Losing a thin layer is normal. Losing the whole thing isn’t, because the tooth is open to bacteria.

For more ways to get through the night, see how to sleep with a toothache.

What not to do

• Don’t take more pain reliever than the label allows. If you need more, call your dentist.
• Don’t put aspirin on the tooth or gum. It burns the tissue.
• Don’t take leftover antibiotics. Only a dentist or doctor should decide whether you need them.
• Don’t skip the crown appointment, even once the tooth feels fine.

When to call your dentist

Call your dentist or endodontist if you have any of the signs in the box on this page. The AAE’s list:

• Severe pain or pressure lasting more than a few days
• Swelling you can see, inside or outside your mouth
• An allergic reaction to a medicine: rash, hives or itching
• Your bite feels uneven
• The symptoms you had before treatment come back

Cleveland Clinic adds that pain that gets worse after treatment, especially throbbing, is a reason to call. The AAE calls prolonged or increasing pain uncommon and says it should be checked.

If swelling spreads, you have a fever with a swollen face, or you have trouble swallowing or breathing, go to the ER.

When a root canal needs a redo

Most root canals work and last many years, often a lifetime. Some don’t heal, and a treated tooth can also get reinfected later. The AAE says this can happen months or even years afterward.

The usual clue is that the symptoms you had before treatment come back. Swelling or a pimple-like bump on the gum can be a sign of an abscess, Cleveland Clinic says. See tooth abscess.

The usual options:

• Retreatment. The dentist or endodontist reopens the tooth, removes the old filling material, looks for missed canals or new infection, cleans and refills the canals, and seals it again. It then needs a crown or filling.
• Endodontic surgery. The AAE says surgery can save the tooth when a regular root canal isn’t enough, for example to find a hidden crack or canal.
• Taking the tooth out, then replacing it with an implant or a bridge.

A dentist needs an exam and X-rays to tell which fits. For what treatment and the crown usually cost, see root canal cost. If you don’t have insurance, a dental savings plan (a discount membership, not insurance) can lower the price at participating dentists.

How to keep it from coming back

A root canal tooth can still get decay or break, and a leak around the filling or crown is one way it gets reinfected.

• Get the permanent crown or filling placed soon. The AAE lists a delayed crown as one reason a root canal fails.
• Brush twice a day with a fluoride toothpaste, and clean between your teeth once a day.
• Keep up with checkups, so a loose crown or new cavity gets caught early.
• If you grind your teeth, ask about a night guard. See jaw and tooth pain from grinding.

A good electric toothbrush makes the daily habits easier. See the best electric toothbrush.