Medically reviewed by Dr. Sam Wood
A root canal is a procedure that removes infected or inflamed pulp from inside a tooth, cleans and seals the space, and saves the tooth from extraction. It is done under local anesthetic, usually takes one or two visits of 60 to 90 minutes, and in the US typically costs $700 to $1,800 before the crown. Modern root canals feel much like getting a filling.
What a root canal actually is
Every tooth has a soft core called the pulp, made of nerves, blood vessels, and connective tissue. It runs from the crown of the tooth down through narrow channels, the root canals, to the tip of each root. When bacteria reach the pulp, through deep decay, a crack, a failing filling, or trauma, the pulp becomes inflamed and eventually dies. The infection then has nowhere to go except out the root tip into the jawbone, where it forms an abscess.
A root canal treatment, properly called endodontic therapy, removes that diseased pulp. The dentist opens the top of the tooth, cleans and shapes the canals with fine instruments, disinfects them, and fills them with a rubber-like material called gutta-percha. The opening is sealed with a filling, and in most cases the tooth is then covered with a crown.
The tooth is no longer alive in the sense of having a nerve, but it stays anchored in the bone and keeps functioning. That is the whole point: a root canal is how you keep a tooth that would otherwise have to come out.
Signs you might need one
Some teeth that need a root canal cause no symptoms at all and are found on an X-ray. More often, there are warning signs:
- Pain when biting or chewing, or a tooth that hurts when tapped
- Lingering sensitivity to hot or cold that lasts well after the stimulus is gone
- Spontaneous, throbbing pain, often worse at night or when lying down
- Swelling or tenderness in the gum near the tooth
- A pimple-like bump on the gum that may drain pus
- A tooth that has darkened or turned gray
- A cracked, chipped, or deeply decayed tooth
Pain that suddenly stops is not always good news. It can mean the nerve has died, while the infection continues in the bone below.
Root canal vs. extraction
When the pulp is infected, the realistic choices are a root canal or removing the tooth. Dentists almost always favor saving the tooth. A natural tooth chews better than any replacement, protects the neighboring teeth from drifting, and preserves the bone around it. Replacing an extracted tooth with a dental implant or bridge costs several times more than a root canal and crown.
Extraction makes more sense when the tooth is fractured below the gum line, when there is not enough tooth structure left to hold a crown, or when the bone around it is too damaged by gum disease to keep it stable.
How much a root canal costs in the US
Cost depends mainly on which tooth it is. Front teeth have one canal; molars have three or four, take longer, and are more often referred to a specialist (an endodontist), who charges more than a general dentist.
| Tooth | Typical cost (root canal only) | Notes |
|---|---|---|
| Front tooth (incisor, canine) | $700 – $1,200 | One canal, simplest |
| Premolar (bicuspid) | $800 – $1,500 | One or two canals |
| Molar | $1,000 – $1,800 | Three or four canals; often done by an endodontist |
| Retreatment of a failed root canal | $1,200 – $2,500 | More complex; usually specialist |
| Crown afterward | $1,000 – $2,500 | Needed on most back teeth |
Two things inflate the real total. First, back teeth almost always need a crown afterward, which can cost as much as the root canal itself. Second, an emergency visit for pain relief before the procedure adds an exam and X-ray fee. Ask for a full quote covering root canal plus crown.
Dental insurance usually classifies a root canal as a basic or major service and covers 50 to 80 percent after the deductible, up to the annual maximum. Because that maximum is often $1,000 to $2,000, a molar root canal plus crown can exhaust it. Our root canal cost guide covers the numbers in more detail.
Does a root canal hurt?
The reputation is worse than the reality. The pain people associate with root canals is the toothache that comes before treatment, not the treatment itself. With modern local anesthetics, most patients feel pressure and vibration but not pain. A badly infected tooth can be harder to numb; if you feel anything sharp, tell the dentist and they will add more anesthetic.
Afterward, expect the tooth and surrounding gum to be sore for two to five days, particularly when biting. Over-the-counter ibuprofen or acetaminophen handles it for most people. Severe or increasing pain after the first few days is not typical and should be reported.
What happens during the procedure
1. Numbing. Local anesthetic is injected near the tooth. Sedation is available at many offices if you are anxious. 2. Isolation. A small rubber sheet (a dental dam) is placed around the tooth to keep it dry and free of saliva. 3. Access. A small opening is drilled through the top of the tooth into the pulp chamber. 4. Cleaning and shaping. Fine, flexible files remove the pulp and enlarge the canals slightly. The canals are flushed repeatedly with disinfecting solution. 5. Filling. The dry, clean canals are filled with gutta-percha and sealed with cement. 6. Temporary or permanent seal. The access hole is closed with a filling. If a crown is planned, a temporary filling holds the tooth until the crown visit.
A front tooth is often finished in a single visit of about an hour. A molar, or a tooth with a large abscess, may be done over two visits so that medication can sit in the canals between them.
Recovery and aftercare
- Avoid chewing on the treated tooth until it has its permanent filling or crown. Until then it is more brittle and can crack.
- Take pain relief as directed before the anesthetic wears off, then as needed.
- Brush and floss normally, being gentle around the tooth for a day or two.
- Get the crown placed within a few weeks. Delaying it is the most common reason a root-canaled tooth is eventually lost.
How long a root-canaled tooth lasts
Root canal treatment succeeds in roughly 85 to 95 percent of cases, and a treated tooth that receives a crown promptly can last the rest of your life. Failures usually come from a missed canal, a new leak through a cracked filling or crown, or a fracture. A failed root canal can often be retreated, or the root tip can be removed surgically in a procedure called an apicoectomy.
When to see a dentist
See a dentist promptly if you have tooth pain that lasts more than a day or two, sensitivity to hot or cold that lingers, pain when biting, or a darkened tooth. Seek same-day care, or go to an emergency dentist, if you have facial swelling, a fever with tooth pain, swelling that makes it hard to swallow or breathe, or a bump on the gum that drains pus. A dental abscess can spread and become a medical emergency; it does not resolve on its own.
Frequently asked questions
How long does a root canal take?
A front tooth typically takes 45 to 60 minutes and is done in one visit. A molar takes 90 minutes or more and is sometimes split across two appointments. Add a separate visit for the crown, usually a few weeks later.
Can I drive myself home after a root canal?
Yes, if you only had local anesthetic. If you chose oral or IV sedation, you will need someone to drive you.
Do I really need a crown after a root canal?
For molars and premolars, almost always. A root-canaled back tooth is drier and more brittle, and without a crown it has a high chance of fracturing under chewing forces. Front teeth with minimal decay can sometimes be restored with a filling alone.
Can a root canal be done in one visit?
Often, yes, especially for front teeth and teeth without a large abscess. Two visits are common for molars, retreatments, and teeth with significant infection.
What if I just leave the tooth alone?
An infected pulp does not heal by itself. The infection spreads into the bone, the abscess grows, and the tooth eventually has to be extracted. In rare cases the infection spreads to the face, neck, or bloodstream and becomes serious.
Is a root canal safe during pregnancy?
Yes. Untreated infection is the greater risk to a pregnancy. Dentists use local anesthetics considered safe in pregnancy and shield the abdomen during X-rays; the second trimester is generally the preferred time for non-emergency work.
Sources
- American Association of Endodontists – What is a root canal?
- American Dental Association (MouthHealthy) – Root canals
- Cleveland Clinic – Root canal
- National Institute of Dental and Craniofacial Research – Tooth decay
This article is for general information only and is not a substitute for professional dental advice, diagnosis, or treatment. Always consult a licensed dentist about your specific situation.