What to expect after a root canal appointment.

- Will you have pain or swelling? / How long will it last? / Root canal aftercare: Precautions and pain control methods.

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Reasons for post-op pain slideshow.
Temporary filling precautions slideshow.

What happens after root canal?

Whether it's in between visits, or after your dentist has completely finished your root canal work, you'll no doubt want to know what to expect and what you should do during the hours and days that follow.

To fill you in, we've divided this page up into the following sections:

  • Pain - It's a disappointing fact but some percentage of people will experience some level of discomfort (and possibly even swelling) after their scheduled root canal visit. For those who do, this section provides information about possible causes and remedies.
  • Aftercare - You have to keep in mind that even though your root canal therapy has been finished, your tooth hasn't yet been fully restored. And how you tend to it during the days and weeks that follow can have a significant effect on both it and its just completed work.

A) Will you have any pain after your root canal appointment?

The most accurate answer to this question is yes, it's likely but most people don't.

It's generally reported in dental literature that roughly 40% of patients report experiencing some level of discomfort after their endodontic treatment. Of course this number includes all cases lumped together, ranging from just slight to the most severe. (Sadaf 2014, Mokhtari 2016) [page references]

How much pain can you expect?

Study #1 -

The findings of Sadaf (2014) give an idea of what might be expected.

  • This study monitored 140 patients during the day (24 hours post-op) following the completion of their (two-visit) root canal therapy.
  • 57% reported no discomfort after their work. For those who did, 22% reported mild, 19% moderate, 1% intense, and 1.4% unbearable pain.

Comment - These findings parallel the 40% post-op pain number cited above (43% did experience discomfort). But they also reveal that roughly 80% of patients either experience just minimal or no pain.

Study #2 -

Another study (ElMubarak 2010) monitored patient's completing their endodontic treatment (requiring either 1 or 2 visits) at points 12 and 24 hours post-op.

The findings were somewhat different than those reported by the Sadaf study. Both intervals shared similar numbers:

  • At 24 hours - 89% developed no discomfort. 2% experienced mild, 1% moderate and 9% severe postoperative pain.

Comment - In a positive light, over 90% of patients had just minimal or no pain. Although admittedly, almost 1 in 10 experienced significant discomfort.

Endodontic flare-up.

Both of the studies above evaluated patients after the completion of their work. But some root canal visits are intermediary ones, where just a certain stage of the process is performed.

To address this difference we'll cite a literature review by Tsesis (2008). This paper evaluated published research involving "endodontic flare-up."

  • Flare-up was defined as pain or swelling that developed after any type of scheduled root canal appointment that necessitated the need for an unscheduled dental visit to address it.
  • (For this review, the flare-up had to occur within 48 hours following the patient's procedure.)

The paper determined that the incidence rate for flare-up lay on the order of about 8%.

Comment - This number isn't exactly inconsequential. (It may suggest that the best time to schedule a root canal appointment is relatively early in the week and when you won't be traveling.)

However, this paper also reveals that for the vast majority of people (92%), if problems do develop they are generally relatively easy to manage (most likely via the use of OTC or prescription products, if needed). But we'll admit, that doesn't mean that the members of this group didn't suffer any or weren't inconvenienced.

Longer time frames.

As further example of what you might expect, another study (Al-Negrish 2006) followed a group of 112 patients for a period of one week after the completion of their root canal therapy. If determined:

  • At two days post-op: 80% of patients had no pain, 8% had slight pain, and 12% had moderate to severe pain.
  • At day 7: 93% patients had no pain, 4% had slight pain, 3% had moderate pain and one was experiencing severe pain.

Comment - All of the studies on this page collectively suggest that while problems can occur, for the vast majority of people their endodontic work is completed with just mild or no postoperative symptoms.

What type of pain can you expect?

In routine cases:

  • The discomfort typically starts within a few hours after your root canal appointment.
  • It may persist for several hours up to several days.
  • The severity of the pain typically decreases over time.
  • While not the norm, swelling may form.

(Sadaf 2014, Mokhtari 2016)

What causes after-root canal treatment pain?

Over instrumentation can result in tissue inflammation.

Overinstrumentation can cause post-operative pain.

a) The discomfort you notice is probably caused by inflammation.

The most common source of pain after root canal treatment is inflammation of the tissues that surround the tooth's root (termed "periradicular inflammation"). They may be irritated by any and all of the following types of events.

  • Root canal files that have poked beyond the end of the root (overinstrumentation).
  • The escape (extrusion) of bacteria and debris from the root's tip.
  • Leakage of solutions and medicaments used during the root canal process into the tissues surrounding the root.
These events aren't necessarily preventable.

It's important to point out that despite a dentist's best efforts to minimize the above from occurring, being able to absolutely prevent them is something that lies far beyond their control.

b) Infection may play a role.

It's possible that the act of performing a tooth's root canal therapy has triggered the activation of bacteria living within it. If so, an acute infection may develop.

But in the majority of cases, the discomfort a person notices after their appointment is primarily due to tissue inflammation without the complication of active infection.

c) Additional possibilities.

Other factors that can cause pain that's noticed after treatment is a "high" dental filling or gum tissue trauma caused by the rubber dam clamp used during the procedure.

Does post-op pain indicate that your root canal treatment has failed?

There's no reason to expect that what you experience immediately after having your endodontic treatment performed is an indicator of its long-term success.

  • The development of pain after receiving treatment correlates with the intensity of the tissue irritation that took place during the work.
  • Root canal failure occurs when a source of tissue injury persists. (This relates to the quality of work and its ability to perform its intended functions).

Predictors of pain after root canal work.

There are some risk factors that tend to correlate with which patients will or won't experience discomfort after their root canal appointment.

Preoperative pain = Postoperative pain.

A study by Sadaf (2014) determined that the biggest risk factor for postoperative discomfort is having preoperative pain. 83% of patients whose tooth hurt prior to their root canal appointment experienced pain afterward. In comparison, only 17% of those without symptoms did. (Many studies have reported similar findings.)

As lesser factors, this study also determined that:

  • Females are more likely to experience discomfort (65% vs. 35% for males). (Other studies have reported similar findings.)
  • Possibly the type of tooth receiving treatment is a factor. With this study 50% of patients experienced moderate pain when a lower molar was treated vs. 35% for upper ones. Lower numbers were associated with other types of teeth. (Not all studies have found tooth type to be a relevant factor.)

Managing post-root canal pain.

Since the most likely cause of discomfort after a root canal appointment is periradicular (around the root) tissue inflammation (see above), a dentist's initial treatment is typically focused toward managing it. A paper by Jayakodi (2012) discusses the following treatment approaches.


Whenever a medication is selected for use, the patient must evaluate the product's labeling so to make sure it's use is appropriate for them. The product's dosing recommendations should not be exceeded.

NSAID analgesics.

Dentists frequently use over-the-counter (OTC) "nonsteroidal anti inflammatory drugs" (NSAID's) as their first choice in treating tissue inflammation triggered by root canal work.

Ibuprofen (Motrin, Advil) is typically the drug selected. The use of a NSAID alone is usually sufficient for what most patients experience.


For healthy full-sized adults (no complicating factors and under the guidance of their dentist), a common regimen is: 200 to 400 mg orally every 4 to 6 hours as needed for pain relief.


In cases where the use of an NSAID cannot be tolerated by the patient (known sensitivity to NSAID's or aspirin, gastrointestinal ulcerations, NSAID complicated hypertension), a dentist will typically turn to the use of acetaminophen (Tylenol).


For healthy full-sized adults (no complicating factors and under the guidance of their dentist), a common regimen is: 325 to 650 mg every 4 to 6 hours as needed for pain relief.

Antibiotic capsules.

Prescription medications.

If the patient's pain can't be controlled by one of the above drugs, a narcotic analgesic (prescription pain reliever) may be required. It's sometimes given in combination with an NSAID.


As stated above, tissue irritation as opposed to active bacterial infection is the most common cause of a patient's pain after root canal therapy. And for that reason the initial treatment of what a dentist interprets as a routine case typically won't include the use of an antibiotic.

If at any time they have reason to suspect that infection does play a role, an antibiotic will be prescribed.

Keep in touch with your dentist.

It should go without saying that in all cases where you are experiencing any type of problem, you should always feel free to contact your dentist. They are familiar with the statistics above and fully expect that some percentage of their patients will require their assistance.

Preventing post-root canal treatment pain.

Premedication with an NSAID before root canal work may help to limit or prevent the amount of postoperative discomfort a patient experiences. Ibuprofen (Motrin, Advil) is a common choice.

Mokhtari (2016) determined that a single 400mg dose of ibuprofen one hour prior to the patient's appointment was effective in reducing pain over the first 8 post-operative hours.

A rubber dam clamp.

A rubber dam clamp.

Other possible sources pain after root canal.

a) Gum tissue trauma.

During each root canal visit, your dentist will isolate your tooth by placing a rubber dam around it. The prongs of the metal clamp used to hold this rubber sheet in place may traumatize (pinch, bruise, cut) the tooth's surrounding gum tissue.

  • The tenderness you notice should just be minor and can be expected to disappear in a day or so.
  • The use of a salt-water rinse may help to speed up healing. (1/2 teaspoon of salt to a cup of warm water. Rinse every three to four hours. Spit the rinse out.)

b) A high temporary filling.

If the "bite" of the filling that your dentist places at the completion of your dental visit is too "high" (too tall, in the sense that when you close down you strike the filling first) your tooth may become traumatized and begin to hurt.

  • The needed solution is that you return to your dentist's office so they can buff the filling down until its bite is correct.
  • Since this trauma causes inflammation of the tissues that surround the tooth, even after the filling has been trimmed the pain may continue for some time.

    The inflammation management techniques discussed above would be appropriate for this problem too.

B) Root canal aftercare: What precautions should you take?

After an appointment, don't look for trouble. It's usually best to exercise caution with a tooth that's either having endodontic therapy or has just had it completed. Until your dentist tells you otherwise, you should favor the tooth. Here are some reasons why:

A temporary seal is placed in a tooth between root canal appointments.

Take it easy on your tooth's temporary filling.

  • The filling may break. - In those cases where a tooth's treatment requires more than one appointment, the temporary filling that's used to create a seal to protect your dentist's work might break or come out.

    If it does, saliva (and the bacteria and debris it contains) will recontaminate the interior of your tooth and your dentist will have to spend your next appointment cleaning out your tooth a second time.

    Even in the case where a tooth's treatment has been completed, if the temporary filling that's been placed looses its seal, coronal leakage may occur. (A situation where bacteria are able to recontaminate the treated tooth's interior.)

  • The tooth may break. - Since the way their tooth feels is now back to normal, a person is often eager to make use of it again.

    Until your dentist has had a chance to finish rebuilding your tooth, it should be considered fragile. What a disappointment it would be to spend the time, effort, and money to have root canal treatment performed, only to have the tooth irreparably break or crack before it was fully restored.

  • Foods to watch out for. - In light of the above, avoid using a root canal tooth to bite into or chew hard or crunchy foods. Notably, this might include items like raw vegetables (carrots, celery) and hard candies. But really, due to a tooth's potentially fragile state, any number of other kinds of foods might be able to cause damage too.

Temporary filling overhangs may make it difficult to floss.

Be careful when flossing your tooth's temporary filling.

Routine post-op care.

  • Tooth brushing. - All teeth require regular brushing and a tooth that is receiving, or has received, root canal treatment is no exception. In the case where your gums or tooth are sensitive, simply do the best that you can.
  • Flossing. - A dentist will need to place some type of temporary filling in a tooth that's receiving root canal therapy. And this type of restoration typically isn't as finely crafted and durable as a "permanent" one is.

    That means, when you floss your teeth don't look for trouble. If your floss feels like it's starting to wedge or snag, back off. Report the difficulties you've had to your dentist so they can make the needed adjustments to your filling.

Rebuilding your tooth after its work has been completed.

All teeth that have received root canal therapy will need some type of final ("permanent") restoration. The kind that's chosen, and the time frame in which it's placed, can greatly influence the long-term success of a tooth's treatment. (We discuss this topic in much greater detail here.)


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