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Pain after root canal: Is it normal?

Experiencing some pain after having root canal treatment is normal.

This pain should go away within a few days. According to experts, it should not last beyond two weeks.

But if the pain continues or intensifies with time, you should see your dentist.

In this article:

  • How much pain after a root canal is normal?
  • What medications may you take to reduce pain after a root canal?
  • What causes serious pain after having a root canal therapy?
  • The solutions your dentist may suggest following your root canal treatment.
  • How to prevent root canals in the first place?

How much pain after the root canal is normal?

The purpose of taking root canal treatment is to reduce pain. The application of local anesthetic and technologically advanced equipment also keep the pain during the procedure to a minimum.

However, the local anesthetic generally wears off within 4 to 6 hours. That is why you may feel pain in your mouth after root canal treatment.

  • Your restored tooth may feel sore for a few days.
  • There may be mild to moderate pain at the root of the tooth.
  • The tooth may feel sensitive at times.

What causes mild pain after the root canal treatment?

  • The root canal procedure involves making an opening into the affected tooth. This process puts pressure on your tooth and jaw.
  • The process also involves pulling out infected pulp from the tooth’s chamber. The pulp is the innermost layer of your tooth. It consists of soft tissues, blood vessels, and nerves. It has a limited capacity to heal itself. The tooth becomes sensitive because the process affects the nerves.
  • Although infected nerves are removed, nerves are still remaining in the nearby tissues. These nerves become sensitive as they come in touch with the dental instruments used for the root canal procedure.

How to treat normal pain during the root canal recovery period?

Over-the-counter painkillers should be good enough to deal with normal pain during your root canal recovery.

These painkillers could be of two kinds:

  • Acetaminophen (For example, Tylenol, Motrin).
  • Ibuprofen (For example: Advil, Nurofen).

You should contact your dentist before taking these over-the-counter painkillers if you:

  • Are taking blood-thinning medication.
  • Are allergic to painkillers.
  • Have kidney issues.
  • Are being treated for tuberculosis or epilepsy.
  • Are pregnant.

In case the over-the-counter medicines are not effective in your case, your dentist may prescribe more aggressive painkillers for you.

Read More: When Do You Need a Crown After a Root Canal?

7 main causes of serious pain after root canal therapy

If the pain is severe, sharp, and lasts beyond a week or two, you have a different situation. Although root canal as a treatment has a very high success rate, such a situation can be real for you.

Several reasons may turn your root canal treatment into a painful experience.

1. Leak in the filling material

Once the infected pulp is removed from your tooth, the pulp chamber is filled with an adhesive filling material.

The root canal may fail if the filling material leaks, letting bacteria from your saliva into your tooth’s root. The bacteria can create a new infection within days.

The leak may happen in several ways, including:

  • There has been a new tooth decay.
  • The seal of the crown has opened up.
  • The adhesive filling did not fill the void properly.

2. Your dental crown or adhesive filling is bigger than the space available to it

An oversized crown or filling can cause unbearable pain in your mouth.

The crown will press your natural teeth on both sides, thus irritating them constantly. In such a situation, your dentist can help. They can polish down your crown or filling slightly, thus reducing the pain.

If a more significant adjustment is necessary, the crown must be removed as required adjustment work cannot be completed inside your mouth.

Removing a crown is a big deal if it is a permanent crown, but not impossible. A crown has to be cut into sections for easy removal in some cases. Removing a temporary crown is a lot easier.

3. Bone infection

The root canal is a treatment for your infected teeth. Your dentist cures your infected tooth by removing the intoxicated pulp from its pulp chamber.

But the root cause of the infection may not be the tooth itself but the bone on which it sits.

The root canal treatment may be completed leaving bacteria in your infected bone. In such a case, bacteria may attack the tooth again.

Such an attack may cause temporary discomfort to your mouth, but it is not meant to last. Contact your dentist to make sure that this is the case for you. Dentist-recommended doses of antibiotics are enough to treat the bone infection.

4. Bleach leak

Dentists use a liquid bleach called sodium hypochlorite to clean the pulp chamber during the root canal treatment. It is a corrosive substance used to clean swimming pools and wastewater.

This bleach can come in contact with your soft tissue during the root canal process. The result is immediate pain.

Your dentist will immediately flush the area, but it may be too late already. The pain may linger some time before disappearing.

5. A second or third infected tooth canal

A tooth at the back of your mouth has several canals. If infected, your dentist may unknowingly disinfect only one canal, leaving bacteria in other canals.

This situation may occur if the other canals do not show any infection before the infected tooth is examined.

These new infections have to be treated as well as the old infection, and until that treatment is complete, you may experience a serious toothache.

6. Unintentional release of dental cement

Root infection generally damages the tip of the root. While filling the canal, it may be possible that some dental cement gets released out of the tooth’s pulp chamber through the tip.

If that is the case, the released cement will create pressure on the bone, thus making the tooth’s root painful.

According to dentists, this pain is supposed to disappear with time.

7. Undiscovered crack in the tooth

It can also happen that there is a crack in your tooth that remained undetected during the examination.

This crack or damage can let bacteria in, which can ultimately cause tooth decay, thus making the filling unsustainable.

How your dentist may treat a failed tooth canal

If you cannot forget your pain during the recovery period, which is so severe that it interferes with your daily life, do not hesitate to contact your dentist.

Your dentist will examine the tooth and suggest one of the following two solutions:

1. Endodontic retreatment

This method is aimed at saving your tooth instead of extracting it.

You may need it during your healing period or even months after root canal treatment.

An endodontist will reopen your tooth to remove the filling material. They will examine your tooth for cracks, fractures, trauma, or any new infection in other canals. Any infection will be removed, and the new filling will seal the canal.

2. Extraction

In some cases, pulling out your tooth may be your only option.

The extraction of the tooth will begin a new phase of dental treatment procedures, which may include filling the socket with a:

  • Dental implant
  • Partial denture
  • Dental bridge

Your dentist will explain which of these two solutions is best for you.

How to prevent root canals in the first place?

You can keep root canal treatment away by practicing good oral habits. Root canals are generally the consequence of tooth decay. Follow the instructions below to have a healthy mouth:

  • Brush your teeth at least twice daily with a soft-bristled brush.
  • Floss your teeth regularly.
  • Fluoride-rich toothpaste keeps your teeth strong. Find yours from your favorite store.
  • Avoid eating sugary food as much as you can. They are not good for your oral and general health.
  • Quit smoking.
  • Do not miss your appointments with your dentist. They are too important.

Final word

If the pain during your root canal healing period is so severe that it interferes with your daily activities, you should consult your dentist immediately.

Leaving a problematic root canal untreated is a bad idea and can complicate your situation.


  • NHS. Information and advice after a local anesthetic procedure: Information for patients.
  • NHS. Root canal treatment.
  • American Association of Endodontists (AAE). Myths About Root Canals.