An Overview of Root Canals

Medically Reviewed by Zilpah Sheikh, MD on August 27, 2023
Written by WebMD Editorial Contributors
8 min read

Root canal is a dental procedure to repair and save your tooth when it's badly decayed, damaged, or infected.

Why would you need a root canal?

You might need a root canal if your tooth pulp, which is composed of nerves and blood vessels, becomes infected or damaged. During the procedure, the pulp is removed, and the inside of your tooth is cleaned and sealed.

Are root canals painful?

You might assume root canals are painful, but many people report they're no more painful than getting a filling. The discomfort you may have leading up to this kind of dental care can be very painful but not the procedure itself.

The pulp or pulp chamber is the soft area within the center of the tooth and contains the nerve, blood vessels, and connective tissue. The tooth's nerve is in the "root" or "legs" of the tooth. The root canals travel from the tip of the tooth's root into the pulp chamber.

A tooth's nerve is not important to a tooth's health and function after the tooth has emerged through the gums. Its only function is sensory—to provide the sensation of heat or cold. The presence or absence of a nerve will not affect the day-to-day functioning of the tooth. However, after treatment, the tooth is less viable and more susceptible to fracture.

When pulp is damaged, it breaks down, and bacteria begin to multiply within the pulp chamber. The bacteria and other dying pulp remnants can cause an infection or abscessed tooth. An abscess is a pus-filled pocket that forms at the end of a tooth's root. In addition to an abscess, an infection in the root canal of a tooth can cause:

  1. Swelling that may spread to other areas of the face, neck, or head
  2. Bone loss around the tip of the root
  3. Drainage problems extending outward from the root. A hole can occur through the side of the tooth, with drainage into the gums or through the cheek into the skin.

A tooth's pulp can become irritated, inflamed, and infected due to deep decay, repeated dental procedures on a tooth, large fillings, a crack or chip in the tooth, or trauma to the face.

Signs you may need a root canal include:

  1. Severe toothache upon chewing or application of pressure
  2. Prolonged sensitivity (pain) to hot or cold temperatures (after the heat or cold has been removed)
  3. Discoloration (darkening) of your tooth
  4. Swelling and tenderness in nearby gums
  5. A persistent or recurring pimple on your gums

It's possible you may need a root canal but have none of these symptoms.

How long does a root canal procedure take?

A root canal requires one or more office visits. It can be performed by a dentist or an endodontist. An endodontist is a dentist who specializes in the causes, diagnosis, prevention, and treatment of diseases and injuries of your teeth's dental pulp.

The choice of dentist depends, to some degree, on the difficulty of the root canal procedure you need, and your dentist's comfort level in working on your tooth.

Your dentist will help decide who's best suited to perform a root canal for you.

The first step in a root canal is to take an X-ray. That's to see any signs of infection in your surrounding bone. Your dentist or endodontist will use local anesthesia to numb the area near your tooth. Anesthesia may not be necessary because your nerve is dead. But most dentists anesthetize the area to make you more relaxed and at ease.

Next, to keep the area dry and free of saliva during treatment, your dentist will place a rubber dam (a sheet of rubber) around your tooth.

Your dentist will then drill an access hole into your tooth. They will remove the pulp, along with bacteria and related debris. The cleaning-out process is accomplished using root canal files. Your dentist will place a series of these files, of increasing diameter, into the access hole. These files are worked down the full length of your tooth to scrape and scrub the sides of your root canals. Your dentist uses water or sodium hypochlorite to flush away the debris.

Once your tooth is thoroughly cleaned, it needs to be sealed. Some dentists like to wait a week before sealing the tooth. For instance, if there is an infection, your dentist may put a medication inside the tooth to clear it up. Others may choose to seal the tooth the same day it is cleaned out. If a root canal is not completed on the same day, a temporary filling is placed in the exterior hole in the tooth to keep contaminants out between appointments.

At the next appointment, to fill the interior of the tooth, a sealer paste and a rubber compound called gutta-percha are placed into your tooth's root canal. To fill the exterior access hole created at the beginning of treatment, a filling is placed.

Root canal and crown

The final step may involve further restoration of the tooth. Because a tooth that needs a root canal often is one that has a large filling or extensive decay or other weakness, a crown, crown and post, or other restoration often needs to be placed on the tooth to protect it, prevent it from breaking, and restore it to full function. Your dentist will discuss the need for any additional dental work with you.

A root canal should relieve the pain you feel. Until your root canal is completely finished—that is, the permanent filling is in place and a crown, if needed, is in place—it's wise to minimize chewing on the tooth under repair. This step will help avoid recontaminating the tooth's interior and may prevent a fragile tooth from breaking before the tooth can be fully restored.

How long does it take to recover from a root canal?

You'll recover in a day or so if you don't have an infection or complications. For the first few days, your tooth may feel sensitive due to natural tissue inflammation, especially if there was pain or infection before the procedure. This sensitivity or discomfort usually can be controlled with over-the-counter pain medications such as ibuprofen (Advil, Motrin) or naproxen (Aleve). You will probably be able to return to your normal activities the next day.

As far as oral health care is concerned, brush and floss as you regularly would, and see your dentist at normally scheduled intervals. Because the final step of a root canal is the application of a restoration, such as a crown or a filling, it won't be obvious to others that you had a root canal.

How long does a root canal last?

A root canal is highly successful. The procedure has more than a 95% success rate. Many teeth fixed with a root canal can last a lifetime.

Signs of infection

Despite your dentist's best efforts to clean and seal a tooth, new infections might emerge. Among the likely reasons for this include:

  1. More than the normally anticipated number of root canals in a tooth (leaving one of them uncleaned)
  2. An undetected crack in the root of a tooth
  3. A defective or an inadequate dental restoration that has allowed bacteria to get past the restoration into the inner aspects of the tooth and recontaminate the area
  4. A breakdown of the inner sealing material over time, allowing bacteria to recontaminate the inner aspects of the tooth

Sometimes, re-treatment can be successful. Other times, an endodontic surgery must be tried in order to save the tooth. The most common endodontic surgical procedure is an apicoectomy or root-end resection. This procedure relieves the inflammation or infection in the bony area around the end of your tooth. In this procedure, the gum tissue is opened, the infected tissue is removed, and sometimes the very end of the root is removed. A small filling may be placed to seal the root canal.

The cost varies depending on how severe your problem is and which tooth is affected. Many dental insurance policies cover it. But if you don't have insurance, here are typical costs for a root canal, according to the American Dental Association:

  • Front tooth: $620-$1,100
  • Bicuspid (mid-mouth): $705-$1,250
  • Molar: $870-$1,472

These costs can vary according to where you live, whether you go to a specialist or a general dentist, and other factors.

Saving your natural teeth is the best option, if possible. Your natural teeth make it possible for you to eat a wide variety of foods necessary to maintain proper nutrition. A root canal is the treatment of choice.

The only alternative to a root canal is having your tooth pulled or extracted. Your tooth is then replaced with a bridge, an implant, or a removable partial denture to restore your ability to chew and to prevent adjacent teeth from shifting. These alternatives are more expensive than a root canal. They also require more treatment time and additional procedures to your adjacent teeth and supporting tissues.

Some of the reasons your tooth's pulp becomes inflamed and infected are deep decay, repeated dental procedures on a tooth, and large fillings. So, following good oral hygiene practices (brushing twice a day, flossing, using an antiseptic mouthwash at least once a day, and having regular dental checks) may reduce your need for a root canal. Tooth trauma from sports-related injuries can be reduced by wearing a mouth guard.

  • A root canal is a dental procedure to save your tooth when it's damaged or infected.
  • Root canal is the best treatment when the pulp of your tooth is damaged. Your only other option is having your tooth pulled.
  • Some reasons your tooth's pulp gets inflamed and infected include deep decay, repeated dental procedures on the same tooth, and large fillings.
  • Many insurance plans cover at least part of the cost for a root canal.
  • Root canal can be done by a general dentist or a dental specialist called an endodontist.
  • Practicing regular oral hygiene like brushing, flossing, and seeing your dentist can help prevent the need for a root canal.
  • Do I need antibiotics after a root canal?

Experts don't believe antibiotics help with symptoms after a root canal. Research backs this up, finding antibiotics have risks and no benefits after a root canal.

  • Can I eat after a root canal?

You should avoid chewing hard foods or biting down heavily until you've been cleared by your endodontist or dentist. Don't chew any food, or drink hot or cold liquids, for the first hour.

  • Will my face be swollen after a root canal?

Not usually. But if you see swelling inside or outside your mouth after a root canal, notify your dentist or endodontist immediately.