Signs and symptoms of failed root canal treatment -

Symptoms that you may notice - Sensitivity / Pain / Swelling.  |  The subtle indications your dentist knows to look for.  |  If you suspect problems, what should your next step be?

Signs of

Link to indications of endodontic failure.

Signs of

Link to signs of root canal failure section.

Signs that your root canalled tooth has problems.

While the root canal therapy that's been performed for your tooth will hopefully last you a lifetime, complications and treatment failures can and do occur. This may even take place with teeth that have an established history of providing you with years, or even decades, of successful service.

What should you watch out for?

This page outlines clinical signs and symptoms that are frequently associated with failed endodontic therapy.

That includes both indications that you the patient may notice, and also the more subtle hints that are often only obvious to the trained eyes of a dentist.

Following that discussion, this page also explains what your next steps should be if you suspect problems.

More information about root canal failure.

As companion pages to this one, we also discuss the following associated topics:


Common Signs and symptoms of root canal failure.

A) How can you tell if your root canalled tooth has a problem?

Many of the signs and symptoms of failed or failing root canal therapy are the same ones as those that originally signaled the tooth's need for treatment. As a brief overview, here are some of the things to look for:

1) Sensitivity to pressure -

Having persistent or renewed discomfort with a treated tooth typically isn't a good sign.

  • The discomfort noticed might range from just slight tenderness to outright pain.
  • It may be felt when biting/closing your teeth together, tapping on your tooth (sensitivity to percussion) or directing forces to the tooth from the side (pressing, tapping).

    (When a dentist evaluates a tooth for this symptom, it's referred to as a percussion test.)

The cause.

Typically this type of sensitivity is a sign of inflammation in the tissues that surround the tooth's root.

The general scenario.
  • Most cases of root canal treatment failure involve a situation where infection has reestablished itself inside the tooth. (This page explains the types of tooth and/or treatment technical issues that frequently result in endodontic therapy failure.)

    (The microorganisms involved are usually bacteria but in some cases they may be fungi [fungus].)

  • Microorganisms and infection byproducts [pus] that leak out of the tooth trigger an inflammation reaction in the tissues surrounding its root. It's the symptoms associated with this process, in these tissues external to the tooth, that result in its sensitivity to percussion.

Section references - Hargreaves, Tronstad

2) Swelling. -

Since failed endodontic cases typically do involve the presence of infection, swelling is often observed.

  • The tissues affected may be limited to just those adjacent to the tooth. Or possibly even just those in the immediate area of its root tip.

    At the other extreme, the swelling may be extensive and extend into the patient's face, or even neck.

  • The extent of swelling that's present at any one point in time will simply correlate with the current level of activity of the infection, which can fluctuate (days, weeks, months).
  • While not always noticeable, swollen tissues typically are tender to touch. (For this reason, palpation is an important examination method for the dentist to use.)
Picture of a sinus tract indicating failed endodontic therapy.

A persistent gum boil can be a sign of infection associated with failed root canal therapy.


With some cases, a vent may form through which the pus from the infection can drain, thus keeping the level of swelling that occurs to a minimum.

This type of lesion (formally referred to as a "sinus tract") typically takes the form of a persistent gum boil whose position is in the region of the tip of the tooth's root.

Due to the draining pus, a bad taste or odor may be present. Additionally, the tissue around the lesion's opening may be tender. However, in cases where these symptoms are not noticed, the tract may lie undiscovered, possibly even for years.

This page provides more detailed coverage about these lesions: What is a sinus tract?

3) Thermal sensitivity.

This symptom isn't as characteristic for failed endodontic work as pain and swelling. But experiencing it is a possibility.

Since the tooth's previous treatment removed its nerve tissue, a response to hot or cold would not be expected. But in cases where one or more of a tooth's root canals have been overlooked and therefore not treated, this type of sensitivity is possible. (Hargreaves)

Related: How a dentists tests for thermal sensitivity.

Section references - Hargreaves

4) How a tooth's symptoms may change.

The level or degree to which a person experiences symptoms can fluctuate. The time period involved might be days, weeks or months.

  • What's noticed at any particular point in time will generally correspond with the current level of activity of the infection associated with the tooth.
  • With any luck, the person's immune system can keep the tooth's infection in check and relatively confined within it. If so, the symptoms they notice may be quite limited.
  • However, and as a worst case scenario, teeth with failed endodontic work have the potential to flare up at any time, resulting in an acute apical abscess.

5) Symptom variability is common.

It must be stated that what we've outlined above is not all inclusive. Your failing tooth may display additional symptoms, or possibly none at all.

Variability is commonplace, and that means that with many cases it will take your dentist's best efforts in detection and interpretation to be able to definitively conclude that your tooth's root canal work has failed.

B) Having symptoms doesn't always indicate endodontic failure.

It's possible that the symptoms you've noticed are not associated with your tooth's root canal work per se. Here are some possibilities:

1) Referred pain -

The nerve that services a tooth will have the duties of servicing other teeth and structures too. And it's possible that a dental or medical problem associated with one of them may cause sensations that just happen to feel like they're coming from your root canalled tooth.

2) Persistent Dentoalveolar Pain disorder (PDAP) -

PDAP disorder is a relatively new term used to label situations characterized by this set of events:

  • Pain associated with a tooth signals its need for root canal therapy.
  • But following its treatment, the patient continues to experience discomfort with the tooth, for months on end.
  • On evaluation, nothing can be found at fault with the tooth or the endodontic treatment it has received.

PDAP cases can be especially problematic, and difficult for a person to endure. For instance, it often takes a dentist some time to finally arrive at this diagnosis. And even then, possibly only after subjecting the tooth, or even neighboring teeth, to dental procedures that have no chance in providing a solution.

And since the underlying cause of PDAP disorder is unknown, treating it is unpredictable. Complete resolution of the patient's pain may not be possible.

We've given our coverage of this condition its own page. You can find it here: Persistent dentoalveolar pain disorder.

3) Tempromandibular joint disorder (TMJ) -

TMJ disorder, a condition involving pain and limited function of the jaw joint and the muscles that operate the jaw, is usually precipitated by a person's habit of clenching and grinding their teeth. (Dentist refer to this activity as bruxism.)

  • While the actual cause of the pain is due to the TMJ condition, it may feel as though it comes from the area of a tooth, such as one that has received endodontic therapy.
  • As a separate cause of pain, the excessive forces typically involved with bruxism may get directed primarily to just one or a few teeth, causing them to become sensitive (sensitivity to biting pressure would be characteristic).

    When this scenario occurs in association with a tooth that has had root canal therapy, the sensitivity comes from nerve fibers within the ligament that holds the tooth in place, and therefore is not an indication of endodontic treatment failure.


Some signs of endodontic failure can only be detected by your dentist.

An x-ray showing evidence of failed root canal treatment.

The dark spot (radiolucency) at the tip of this tooth's root suggests that a problem exists.

C) Not all problem teeth display symptoms you can detect.

Some teeth that have failed endodontically may not display any symptoms that you, the patient, will really notice.

A common scenario is one where from the patient's point of view, their tooth seems perfectly fine. But during x-ray examination (possibly taken as part of a routine dental checkup, or as planned monitoring of a tooth's work) one of the films suggests that a problem exists.

Usually what the dentist has discovered is referred to as a "radiolucency," like the one shown in our illustration.

The grey area of treatment success.

The point that a tooth's work might be classified as a failure even though it remains asymptomatic brings up the issue of tooth survival vs. case success.

In endodontic terms, "survival" refers to a lack of symptoms while a classification of "success" is associated with the more rigorous standard of both an absence of symptoms and evidence of periradicular (around-the-root) tissue healing (as in no radiolucency is present).

What should you do if you suspect endodontic treatment failure?

a) If your root canalled tooth isn't symptom free, it should be evaluated.

For the most part, if you have a tooth that's had root canal therapy and it continues to have, or has started to show, essentially any type of symptom, it should be examined by your dentist.

What's normal.

The expectation is that following the completion of a tooth's endodontic therapy, following an initial period of healing of the tissues that surround the root, the tooth will remain quiet and symptom free. That's because:

  • The tooth's nerve has been removed, so there's no tissue inside the tooth capable of feeling sensation.
  • While nerve fibers do lie in the tissues that surround the tooth's root, successful root canal treatment resolves any issues (like infection, inflammation) that might create an irritating effect on them.

Per these two accomplishments, the tooth should remain asymptomatic (without symptoms). If it doesn't, it should be evaluated.

b) If something seems wrong, how soon should you have your tooth checked out?

If you notice that something seems amiss with your root canalled tooth you should make contact with your dentist's office promptly so they can determine the level of urgency associated with your case and schedule you accordingly.

Why is doing so important?

Infection typically plays a role in root canal failure, and how active it may become at any one point in time can't be predicted. As such, teeth that have an endodontic problem have the potential to flare up at any time.

As a worse case scenario, a long-standing low-grade infection that has only caused minor symptoms may shift into an acute phase, bringing with it intense pain and significant swelling.

Of course, just because this potential exists doesn't mean that it will happen. But it does mean that there's absolutely no good reason to delay in contacting your dentist's office and seeking their attention. Once you've done so, they can make a determination about the urgency of your needs.

In the case where you can't be appointed immediately, they may feel that phoning in a prescription for antibiotics for you (either to be started immediately or to have on hand if needed) can provide a means of helping to control your current symptoms and/or risk level.


c) Timing your tooth's corrective treatment.

Once a decision has been made about the type of corrective treatment that's required for your tooth, it should be performed within the time guidelines recommended by your dentist, for exactly the same reasons just mentioned.

Until that point in time when your tooth's issues are finally resolved, it still remains unpredictable. And as such, leaves you at risk for complications and/or acute flare up.

As a precaution, your dentist may decide to write you a prescription for antibiotics so you already have it on hand if conditions with your tooth worsen before your definitive treatment can be performed. Their decision for a need to do this will simply depend on the conditions associated with your tooth.

Further reading about endodontic case failure:



An old root canal filled tooth that hurts!

Almost 40 years ago I had an abscess on an upper incisor and it was treated with root canal. Over the years it went grey so I had a veneer. Recently (after eating chocolate) it started to hurt, a sharp pain and sensitivity to heat. My dentist has X rayed it and the root canal seems to be intact. My query: I thought this tooth was dead so how can I be experiencing pain?
Thanks (and for your website)


We're not really going to be able to shed much light on your specific situation. In your case, your solution is to continue to monitor your tooth, and continue to document what types of stimuli cause your discomfort. Keep reporting this information to your dentist. They'll ultimately figure things out. Not all diagnoses are quick, easy or one-visit affairs. The diagnostic services of an endodontist is sometimes needed for difficult cases.

The discoloration of your treated tooth that you noticed is commonplace and not necessarily associated with what you are going through now.

Our page about reasons why root canal treatment can fail explains different problems that may crop up. With previously treated, historically successful teeth, some examples are:

1) The seal created by the tooth's original work may have deteriorated and now bacteria are able to reenter the tooth.

2) A previously treated tooth may develop a crack, which can allow an entry point for bacteria.

While an x-ray will often provide valuable information, it may take time for a tooth's condition to advance to a point where the signs associated with its pathology finally show up on one. Hence the need to maintain contact with your dentist and let them to continue to monitor and reevaluate your situation as they feel is indicated.

Beyond what you mention, it's common that a problematic tooth will develop tenderness, swelling and/or a persistent pimple in the region of its root. So watch for that, because if you notice that it will will help in making the diagnosis. Good luck.

Thank you

I'm so grateful to you to have given such a detailed explanation for my strange tooth.
I will indeed keep in close consultation with my dentist and I have taken note of the various factors you have described.
Thanks again

JS Scotland.

Incisor root canal

I had an incisor crack at the gum line years after root canal because I didn’t get a crown on it. Teeth become more brittle when the nerve is gone since they’re not alive. It was fixed with a post and crown for about 12 years until that, too, cracked the remaining root. It’s now a dental implant which I love!

As Lisa states, the type of

As Lisa states, the type of restoration placed after root canal treatment can play an important role in the tooth's long-term success. We have a page that discusses issues associated with understanding what constitutes an appropriate post-treatment final restoration.

Root Canal Retreatment

Thank you for providing the detailed information for this article. It was both informative and helpful. I appreciate the effort.

Thanks SW.

We fear that you wouldn't have read this page unless you're having problems with a tooth, so good luck with getting the difficulty associated with it resolved.

Tooth pain

I had a root canal filling in one of my teeth eight years ago .
About 2 weaks ago it started really to hurt and i went to the dentist and he prescribed antibiotics for me .
The antibiotics did their job perfectly and the pain was gone . The doctor said i don’t need further treatment.
Is that ok ? Can i have another attack of pain in the near future?


Because we know noting about your specific situation, we can only answer in general terms.

As this page discusses, if root canal treatment has failed it frequently involves the situation where bacteria have recolonized (reinfected) the interior of the tooth. (Possibly the seal created by the original root canal filling material has deteriorated, or the tooth's root has developed a crack, or coronal leakage has occurred, etc..., all of these things are discussed above on this page.)

With this type of situation, taking antibiotics may be able to assist a person's body in controlling the acute flare up of the tooth's infection. But it wouldn't be expected that the bacteria inside the tooth (the source of the infection) would be fully eradicated. (The space far inside the tooth is simply too inaccessible to the body's defense mechanisms.)

So with this scenario, yes there would be risk of another acute flare up sometime in the future, because some of the bacteria still inhabit the interior of the tooth (probably much of the time existing as a chronic, low-grade infection that produces no symptoms).

Textbook treatment usually involves retreating the tooth (performing root canal treatment again), or else extracting it (and replacing it with an artificial tooth).

Often a dentist will write a patient a second prescription for antibiotics as a precautionary measure. The prescription is then filled if the tooth starts to flare up again before definitive treatment has been performed.

Beyond what we've just stated and as a second scenario, an infection associated with a root canalled tooth might have non-endodontic origins. For example, "gum disease" might be the cause.

With this scenario, an antibiotic might be used to help to get the infection under control. And then if the dentist feels that the gum condition can be prevented from reoccurring (like by performing better oral home care, or more frequent dental cleanings), then the patient would not necessarily be at risk for future problems.

With your case, you'll simply have to ask your dentist for more information about your situation and its expected cause.

Root canal treatment

Very detailed and informative. Thank you for the information.

Root canal

Had root canal 6 months ago it was on the left side next to the canine tooth. First it was sensitive to touch on the top. About 4 months afterwards it was sensitive to chew. Now the whole tooth interior is very sensitive.I have to chew on the right side. No crown just a filing. What is causing this sensitivity to this tooth?


We're sorry but we're not going to be able to offer any real insight as to the possible cause(s) of what you are experiencing.

With some cases, what the patient states is simple to interpret and the problem(s) that probably lies at fault relatively obvious to any dentist. With your situation, that's not the case.

There is no question your tooth needs further examination. But the description you give doesn't seem to correlate with a standard textbook set of symptoms. To arrive at a diagnosis, a dentist will need direct evaluation of your tooth. They'll also no doubt want better clarification of what some of the terms you have used refer to.

Since endodontic problems have the potential to flare up, you should give making contact with your dentist some priority just to be safe. Best of luck.

5 year old root canal

After 5 years are there treatments for infection of tooth that had a root canal?


This page can help you understand what your case retreatment options are. And this page outlines different reasons why root canal treatment may fail.

infected root canal

I had a root canal about 15 years ago. I just had xray and the dentist says there is an infection. What is the typical treatment?


That's not a terribly uncommon scenario. (We have a page that gives examples of signs on x-rays that suggest root canal is needed.)

Just above on this page we outline what options exist for failed root canal treatment cases.

Root Canal 3 times

I had a root canal in Feb of last year but tooth was still painful after several months. Returned to dentist and he discovered he missed filling the tip of the root so he redid root canal. Another three months passed and tooth was still painful. He sent me to a specialist and the endo found another root that didn't show in dental xray. This endo redid root canal and cut off part of the tip to eliminate root branch. Now, six months later, this tooth area is still sensitive. I decided to get another opinion and went to another dentist. She put antibiotics around the gums but that didn't help. She recommends extraction because of chronic irritation. Does this seem like a failed root canal and does it seem pausible that now I can't save the tooth? I've spent much $ trying to save this tooth.


Sorry to hear about your troubles. You've been through a lot.

The most informed opinion you could seek about your tooth's prognosis is from your endodontist (the specialist).

Diagnosing/interpreting difficult cases is what they do. Since yours has already treated your tooth, they'll have added insight into your current situation. And because they've been your treatment provider before, hopefully they'll have some empathy for your plight.

First off, you never know. Their evaluation may discover that some other type of issue has caused your recent symptoms: gum disease issues, cracked root, something improper about the "bite" of the tooth, or such. But we'd agree, it seems most likely that the 2nd general dentist you consulted with would have discovered these types of issues.

If the problem is determined to be an endodontic one, then you'll end up with 3 options:

Retreating the tooth - And yes we would agree, treating the tooth a 4th time? Only someone directly evaluating your tooth could make this decision. And we would think that in order to make this recommendation that they would need to see something obviously wrong that they could clearly improve upon (like yet another previously undiscovered root canal).

If an endodontic problem exists and retreatment is not chosen, then yes, extraction is the only other appropriate treatment choice. (The hope would be that you would choose to replace the lost tooth with an artificial one.)

As a 3rd possibility, if the tooth has multiple roots, and the tooth's problems clearly seem to be associated with just one of them, then that offending root is sometimes cut off and removed (referred to as root amputation).

This option isn't always possible. When it is, it doesn't always make a good decision. There are definitely case-by-case issues that must be considered. But we mention it here so you can ask whatever dentist provides your treatment if that option exists for you.

Good luck with this. Sorry we didn't have any positive news for you.

Tooth pain after root canal

Had a crown placed on tooth 30. 3 months later had pain between 30 and 31 and more lateral on tooth 30. Pain is above the seat of the crown on the back of tooth 30 especially when pulling the floss out. The gums are not sore . Had root canal done and still have the same pain. Endodontist had me use steroids,special mouthwash and seems to have given up. Dentist says to try baking soda,peroxide salt mix. CT is negative and they both concur that the root canal was successful. The same pain persists. What should i do? I want save the tooth if at all possible. Help!


Sorry but we're not going to have any suggestions as to a cause or solution.

In terms of seeking evaluation or treatment from appropriate people, an endodontist would be the highest authority that dentistry has to offer on this type of situation. So you've done that correctly.

If your endodontist can't come up with a diagnosis or solution, it would seem reasonable to consult with a second one. Doing so might possibly find a fix, or at the other extreme just a greater realization of how confounding your situation is.

If neither can diagnose your situation, offer a solution, or even offer an appropriate plan for monitoring your tooth to see if any improvement will occur, it would seem to be a reasonable point to give up on the tooth. Best of luck with this.

Canine root canal treatment

Two years ago I had my canine root canal treatment. After three / four treatments I felt pain or rather pressure when I place my finger on the tooth. Plus my tooth felt heavy. I told this to the dentist and he said it would go away, but it didn't. I decided to visit another dentist which then he said the last one treated the wrong tooth and this time I had root canal treatment on my tooth next the canine. Still I had pressure on my canine and then the dentist started to treat again the canine. Still no improvement. This went now on for two years. Now I have visited a third dentist after searching thru internet a specialist. She took X-Ray and started with root canal treatment. This time she explained that my root is very long and the former dentists could not reach the end or tip so she shortened my tooth and did the treatment but today I still feel the same pain or pressure.. No improvement . She also explained that maybe the bacteria extended from my root and that treatment from outside might be necessary by making an incision. For this she recommended having CT next time. I don't know whether this would heal or the right method. But now my tooth feels heavy and still have pressure/sensitive up the tooth. What is happening. I am worried and want this situation the finally end. What should I do? Would the incision treatment re rally solve this problem? Help!! Please...


You use the term "specialist." We assume that means a root canal specialist (an endodontist). If so, you should be in good hands.

Root canal files only come in standard lengths and it seems that the longest size still isn't long enough to treat your tooth, hence the need to trim it shorter so the files can extend into it further.

No dentist wants to trim away sound tooth structure. But if otherwise its root canal treatment can't be done properly, then it must be.

Since a part of root canal treatment involves cleaning the entire length of the tooth, what your endodontist has stated about the other dentists not achieving that would likely explain your continued symptoms.

It's disappointing that your symptoms have reappeared this time.
It could be that some of the bacteria from inside your tooth got pushed out into the tissues surrounding the root during this last treatment. If so, that could trigger a flareup (acute infection). With this scenario however, it should be the final event of this sort.

In regard to the need for a surgical approach:

  • Your endodontist's task of cleaning the entire length of the tooth may have been complicated by the previous root canal work the tooth has had. If so, the surgical procedure you mention might be used to trim off the tip of the root (remove that portion of the root that can't be cleaned properly) and a filling placed to seal of the canal. This is referred to as a apical surgery and retrograde filling placement.
  • The anatomy of the tooth's previously uncleansed portion may be difficult to clean (for example, the root canal may have branches). If so and just like above, a surgical procedure might be used to trim away and seal off this uncleansable portion of the tooth.
  • Your tooth has a long history of being symptomatic, which is probably due to a long standing infection. It may be that the bacteria causing this problem are not just harbored inside your tooth but also have a protected location in the tissues that surround the root's tip. If so, the surgery you mention might be used to remove that nodule of bacteria.

With any one of those scenarios, the procedure might prove to be completely successful.

Of course, your endodontist won't be able to guarantee that the surgical procedure will finally solve your problems. But it's their obligation to give you a realistic idea of its chances. They also have an obligation to explain their suggested treatment in comparison to your other options (which would probably only be tooth extraction and replacement. But that might be more attractive if it carried a significantly higher chance of success).
Best of luck with this.

ache under crown / root canal'd tooth

I guess I'm asking more about the symptoms that would lead one to make the choices in this article. I have a tooth (#30) that has had an ache / sensitivity for about 5-6 weeks. Initially, I made an appt with my dentist and they thought it was the made some adjustments. I was back in for a routine cleaning about a week ago, and told her I still had sensitivity to temperature - actually hot more than cold - and pressure. She told me to try sensitive teeth toothpaste for a couple weeks. She took an xray and certainly looked at the tooth. But with the metal crown, I'm guessing it may be difficult to diagnose. Any thoughts on what is going on? And how long should I allow the toothpaste solution to play out? I've been using it for a week. The tooth doesn't ache or barely at all when I'm not eating or drinking. But can be pretty sensitive when I do!


We're not going to be of much help.

The title of your comment states that your tooth has already had root canal treatment (has had its nerve tissue removed). Because of that, it wouldn't be expected that "sensitive teeth toothpaste" would provide a benefit.

Sometimes it's a neighboring (live) tooth that has the thermal sensitivity and it just feels like it's the root canalled tooth (referred sensitivity). If so, using that kind of toothpaste might provide a solution. But as far as the tooth that's been treated itself, no.

In regard to reading x-rays, it's being able to visualize the area around the tip of the tooth's roots that is usually the most informative in regard to diagnosing endodontic problems. Having a crown on the tooth wouldn't interfere with this.

"Sensitive teeth toothpastes" create their effect by way of building up a coating on the tooth's dentin surfaces. If an improvement is noticed, it would typically be a gradual one.

We looked at the directions for one popular brand and it suggested a 4 week time frame for usage. In your case, it makes more sense to go ahead and report to your dentist about what you've noticed and let them decide how long you should try that solution.

It seems your dentist is trying to give your tooth every opportunity to settle down, which is fine as long as you remain under their supervision and follow their directions.

We will mention that sensitivity to hot stimuli and biting pressure can be indicative of continued problems with treated teeth (failing root canal treatment, a missed canal, etc ...). Only your dentist can determine if this applies in your case (how long the discomfort lasts after being set off by the stimuli is often a key indicator).

It seems your dentist is in the process of trying to make this determination. But until a diagnosis is made and treatment provided, you should stay in contact with them in case things take a turn for the worse. Good luck.

Failed Root Canal

I had my root canal treatment last year May 2017 in my left canine . At first It was perfectly fine all the pain and sensitivity had gone. But after a year, I noticed that the same symtomps re occur. First when I tap or touch my left canine it feels sensitive, then when I touch it on the top outside near my nose upper lips where the root is located it has the same feeling before the sensitivity and pain. So I decided to visit a Dentist and decided to have a Zirconia Crown on it because I think that maybe It will be needed to put a crown instead of a filling only. I already told the Dentist that I already had a root canal with that particular tooth he took an xray and he told me that there is still a small infection on the top of the root he told me that maybe the last dentist that took the root canal treatment for me had failed. I asked him what should I do, do I need to have a RCT again. He just told that he will do the Zirconia Crown because maybe the infected area will be gone after. Or will lessen its symtomps. I listened to him, he do the crown and cleaning everything was perfect the sentivity is not that much as before but still I have the sensitive feeling on that tooth. My question is, is that posible that the sensitivity or pain will eventually go away by itself or I need to have a retreatment for my root canal? Because as what you have shown at the pictures of failed RCT i have the same case on the top layer of my RC there is a black shadow that indicates an infection as shown on my xray results. Please bear with me I need an answer.


An x-ray isn't necessarily diagnostic by itself. For example, the shadow that is seen might be related to the formation of scar tissue that formed as healing took place.

What's concerning is that with your case you state: "when I tap or touch my left canine it feels sensitive, then when I touch it on the top outside near my nose upper lips where the root is located it has the same feeling before the sensitivity and pain."

Those can be classic signs for a tooth that needs root canal treatment (retreatment). And if that is the case, the shadow at the tooth's root tip on the x-ray is confirmation of that (the shadow area [area of infection/inflammation] would correspond in position with the area of tenderness you touch). Additionally, pain/tenderness persisting for a year suggests that healing didn't occur and that a problem still exists.

If a diagnosis of failure is correct (a diagnosis only a dentist actually evaluating you and your tooth can make, not us), then the only solution is to have endodontic retreatment.

In regard to crown placement as a solution:
A crown can create a superior seal for a tooth, and one that's often needed for root canalled teeth. (Coronal leakage can be a cause of root canal failure.)

But if a tooth already has an existing endodontic problem (meaning an already contaminated root canal system), crown placement will do nothing to resolve that issue (the bacteria are already inside the tooth, they can survive just fine if the tooth has a crown on it or not). What's needed in that case is cleaning and sealing the tooth's root canals by performing endodontic (re)treatment.

Root canal tipped over

I have a very old root canal rear molar that is now so far tipped over that it is almost horizontal due to having the molar in front of it extracted years ago. The tooth in front of the extracted one is also a root canal with the tooth in front of it extracted also. The rear molar seems irritated around the gum from both eating on that side of my mouth and brushing it because I have a failed root canal on the opposite side in the back that my dentist is going to remove this week. it looks like I will need to find an oral surgeon to try to extract the tipped over one. I am wondering how I should be taking care of it until then.


If the situation is simple, the logical assumption is that your now horizontal molar accumulates/traps debris (dental plaque, food particles, etc...) underneath its side that now rests against gum tissue.

This accumulation irritates (inflames) the adjacent gum tissue, the signs of which would be redness, tenderness, swelling and possibly bleeding when provoked.

The solution would be to keep this debris cleaned away, thus allowing the gum tissue to heal.

To do so, possibly the side of the tooth that is face down could still be flossed. If not, possibly rinsing around the tooth with an antiseptic type mouthwash would help. The exposed surfaces of the tooth would need to be kept clean (brushed) as effectively as you can too.

Run all of this past your dentist during your up coming extraction appointment. It should just take them a few moments to confirm that this makes the needed plan.

(While you don't mention it, if perchance the root canal treatment of this tooth has been diagnosed as having failed and that's the cause of what you notice, the only way of controlling it's associated infection over the short-term would be via the use of antibiotics prescribed by your dentist. The same would be true if it was diagnosed that the tooth had advanced gum disease associated with it. If the problem stems from the inability of the tipped tooth to now withstand the level of forces it receives, keeping it cleaner may help but generally there would be no solution other than extraction.)

Possible reoccurence of Route Canal infection in tooth # 3

My guestimate is approx. 9 years ago, in 2009, I had a route canal procedure performed on tooth # 3 by an endodontist, the only one in the city of approx. 65,000 people at the time.

In July of 2017, the crown came off of tooth #3, I sought out a new dentist since my dentist of the past 20 years had retired. Because of the emergency, there was only one dentist open on that Friday. The new (one-time O.V.) dentist took an X-Ray (digital ?) of tooth #3 and showed me the picture of it and pointed out where he said: "one (or two) of the canals was/were missing some filling or sealant". When I queried as to how that could occur I believe he said it was not or may not have been completely filled." He then re-cemented the crown back on tooth #3. He did not offer any additional information, data or instructions indicating there was any problem or possibility of any potential problem (I add this because further evidence and research indicated that he should have).

In August of 2017, tooth #4 fractured because it was incorrectly treated in Nov. of 2015. I found a new dentist and she took out some decay after taking an X-ray which she said showed no shadow and therefore the nerve was not affected. However she warned me that since she had taken out some decay to be aware of any pain and go to an endodontist immediately if there was any pain. She put a temporary crown on tooth #4 and due to delays, she put the permanent crown on tooth #4 in May of 2018, some 9 months later. Since she said the temporary cement had come off during the 9 month interval I requested she put it on with temporary cement in case I needed a route canal . I thought within a month or two if pain showed up I would be able to have the endodontist take the crown off easily. It's important to note that no pain was felt at all for the 9 month interval since she put the temporary crown on.

Back in August of 2017, after the 1st dentist had re-cemented the crown back on tooth #3 I had noticed that there was a space (to me it appeared to be significant) between the crown and my gum line. I initially thought (being a layman and ignorant) that the dentist had not fit the crown back on properly since it was not flush with the gumline. The new dentist said however that that was not the case but that my gum had receded (why only from one tooth is my question). She noted that she could put a new crown on it. 9 months later, in May of 2018, she said there may be additional decay in the tooth. I asked her how she could determine that and she took a dental instrument and began her examination by poking extensively around inside the crown by going through the gap between the crown and the tooth on the interior. She then said she could tell there was decay.

This was done on the same visit I believe that she put the new crown on tooth #4.

Within a week to two weeks, I began experiencing pain in what I initially thought was tooth #4. It would become more painful after eating. But when I flossed & brushed my teeth, the pain stopped. Then after dinner I sensed & felt food matter, pasta and other food matter hanging out of my tooth, stuck there and I could not remove it with my tongue. It actually felt, and I sensed this , that the pasta etc. was hanging out from where it felt it was stuck -- caught the between the crown and the gumline, and extending down over the gum and tooth (crown).

I went to the endodontist that I've been going to since around 1990. He had done R.C. on tooth #3 originally. I told him I had pain and my dentist originally had been emphatic that if I had pain after she treated tooth #4 (which had no shadow on the x-ray) to see an endodontist. I saw him a few days ago on June 28, 2018. He took an x-ray, saw no problem and tested tooth #4 with hot and cold and tapping the tooth -- and the results were no sensitivity to hot or cold or to the tapping w the metal instrument. I sat there and he could not give me a definitive answer to why I was having pain.

A few days after I left his office I ate some rice pudding and could sense, actually feel with my tongue that there was rice pudding blocking (and in ?) the gap (space) between the gumline and the ill-fitting crown on tooth #3!

I went on line to research and found some data/information I was completely ignorant of -- and that is that a tooth that has had a route canal performed upon it can go bad, a canal or more than one canal can become reinfected due to the canal(s) not being completely filled & sealed or perhaps the material that was used to seal the tooth had deterioated.

Putting this all together my logic leads me to believe the pain(s) are possibly actually coming from the re-infection of tooth #3 which had a route canal done on it many years ago.

It is not after hours and I have not had a chance to speak to my dentist or endododist about it but I'm asking you since one would think that given all of the data that I've shared with you, they were both aware of and said nothing. Why do I have to be the one to research all of this and figure this out!?

Please advise. My theory seems logical to me given the facts as outlined above. Why didn't they?


Re the emergency dentist - By stating what he did, in his mind he probably felt he had brought the matter to your attention, however ineptly.
Looking at the situation from his perspective: You presented with a crown that had come off of an asymptomatic tooth, whose work had been performed by a specialist.
This dentist knows that not all treatment turns out as perfectly as the practitioner had hoped (often because of obstacles encountered within the tooth) but the level of care performed was at a specialist's level (implying the best possible).
Short of obvious signs of an active problem, and considering the level of treatment the tooth had originally received, and the evident success of the treatment at that point, we're not so sure how much of an issue they should have raised.

Re the endodontist's evaluation of #4 - We just don't see how it would be possible for an endodontist not to include the evaluation of adjacent teeth when investigating #4. And at least at that point in time, one would have to assume that they honestly felt a diagnosis couldn't be made.
In regard to testing #3, sensitivity to percussion would be characteristic for failed root canal work. In the case of unfilled/missed canals, possibly sensitivity to heat could be a symptom too.

None of your symptoms associated with food accumulation stand out to us as indicating an endodontic problem.

We find it curious that the endodontist didn't make mention of inadequacies of the crown on #3. Beyond missed canals/deteriorated canal system seals, root canal treatment can fail related to coronal leakage. Your crown has an "open margin" (in the location of the decay) and as such no longer creates an intact seal over the tooth.

In regard to the changes you've noticed at the gum line on #3, Google the terms "abfraction" and "abrasion." Of course, the changes could be related to decay formation alone.

It seems everyone involved is simply waiting until your symptoms become characteristic enough that a diagnosis can be made and treatment suggested.

No one wants to treat #4 if it doesn't need it. No one wants to suggest the retreatment of #3 (if it needs it it may not be possible, or may not have a high expectation of success, or might require surgical rather than conventional treatment). No one wants to make a new crown for #3 if there's a possibility that it can't be saved.

Possibly the middle ground here is that a temporary crown should be made for #3 to insure a better seal until things can be figured out and which tooth is at fault is determined. But that would be up to your dentists to decide.

We're sure your situation is frustrating. Stay in close contact with both dentists so they know you still have issues and require attention.

Abcessed tooth/ root canal

A week ago I woke from sleep with an explosive pain in face, I looked in mirror, my right side of my face was extremely swollen, eye was swollen shut, lower part of face drooping. This was at 4am, I went to the ER thinking maybe a sinus infection, I was prescribed antibiotics by the doctor...he did no X-rays, did not look in my nose, didn't look in my mouth. I took the antibiotics for 6 days, still having a great deal of pain, I decided to go to the dentist, after his exam it was determined I have an abcessed tooth, following day he started a root canal, he cleaned the canal, but said I have more infection that didn't drain, he sealed the tooth and has prescribed amoxicillin, and has scheduled root canal part two in 10 days. Is this common?


Yes, the way your dentist is treating you tooth is commonplace, and it sounds like you're in good hands with them.

You said they sealed your tooth back up, meaning they're trying to prevent more bacteria from entering the tooth after cleaning it somewhat.

A sealed tooth might flare up (allow pus to build up like it did before), so they've place you on antibiotics to make that event less likely.

They have appointed you for 10 days out, a point after you'll have stopped taking the antibiotics. That way they'll know if the tooth is staying quiet on its own accord, or only via the assistance of the antibiotics (a diagnostic test helping them to understand when they can complete the tooth's treatment).

If perchance you notice problems, especially those similar to what you had before, starting to brew, let them know promptly. Most likely you'll be fine.

root canal / interventions have not made any difference

My upper right molar became unbearable if I bit down on it. Hoping it would right itself, I started chewing exclusively on the left and I did not go back to my dentist for five months.

My dentist saw nothing on the xray and said my filling had failed and then replaced it. But the pain was just as acute, and therefore sent me to his colleague who specializes in root canals, even though I said the resulting "dead" tooth was as sensitive as ever, he said it would settle down and that the crown would take care of everything. But it did not and the pain got even worse if I accidentally bit down on it. I even had it checked by my dentist in the States when I returned for a visit and she said everything looked excellent and give it a little more time. When I returned to Paris my dentist here said give it a little more time. After two agonizing incidents that lasted half a day after accidentally biting down on that side of the mouth, I went back and the dentist suggested that the plaque built up around the tooth under the gum was causing the difficulty. I was sure that was not the cause of my pain but my dentist said his colleague was the best for root canals so this must be the cause. Viola, we had yet again another intervention (over 2000 Euros spent and a year and a half) where he cut the gum away and probably did a bang up job of needed deep cleaning but he admitted he saw nothing alarming. I am going to see him Monday to get the stitches taken out. There is absolutely no change in the pain from the beginning if I bite down on the tooth. Cold and air blown on and the outside of the tooth are a killer. The teeth before and behind have absolutely no sensitivity at all.
What should I tell, suggest, ask. etc. of him? All I want is the pain to stop but I am extremely frustrated by the money (I am not able to spend more huge sums at present), discomfort. and time already spent for no result.
Many thanks in advance for your much appreciated reply.


We would think that seeking further consult from your endodontist, as opposed to just your general dentists, would be important to do.

By nature of their position in the profession of dentistry (challenging cases are referred to them by general dentists), one would have to assume they would have significantly more experience in making a differential diagnosis with cases that display atypical symptoms than the average dentist.

An endodontist typically has 3D imaging capabilities (Cone Beam Computed Tomography) that a general dentist doesn't that might better help them evaluate your tooth.

If per chance your tooth's root canal treatment hasn't been successful, yet it was performed at expert level (by the endodontist), it just seems that whatever problem exists might be something much more likely to be realized, discovered or interpreted by a specialist, especially one who has a history of providing treatment for your tooth. Good luck.

Pain after recent crown and root canal of molar

Last year I was experiencing some pain with #15 molar, particularly with compression. My dentist took x-rays and said there was nothing conclusive but perhaps either a crown or root canal would fix it; he did also say a cracked root could be the problem but couldn't be sure. I opted for a crown. A couple months later, I was still experiencing pain and was referred to an endodontist for 3D scans and a root canal. The scan didn't show any cracks and a root canal was performed. Now in the last month or so I'm getting headaches from the dull pain, which comes and goes. The tooth hurts more when compressed or when I apply pressure on the sides. Another x-ray at the dentist showed cloudiness above the tooth, and the dentist again mentioned it could be a cracked root. My tooth has never felt right even after all the work and $ spent. Is it safe to assume this tooth needs to be pulled after all? Who can definitively tell me whether the root is cracked or not? I might add the dentist is somewhat new to me and I've never used the endodontist before.


Sorry to hear about your troubles. We would think that you need to let your endodontist evaluate your tooth and its current set of symptoms and make a recommendation about possible solutions.

"Who can definitively tell me whether the root is cracked or not?"
Your endodontist would be in the best position to make this determination, although the word "definitively" may not exactly apply.

We read through some published research papers that evaluated dentists' ability to diagnose cracks in sample groups of teeth using 2d and 3d x-ray imaging. It seems cracks were only identified on the order of 75 to 85% of the time.

One problem with a tooth having a crack is that it gives bacteria a location to live. And over time, their presence (the infection they cause) will tend to trigger changes in the bone that surrounds the tooth (you mention the "cloudiness" seen). So, that may help the endodontist determine if/where a crack lies.

"Is it safe to assume this tooth needs to be pulled after all?"
If the tooth is cracked, yes extraction probably is indicated.

A possible middle ground might be root amputation.
If the tooth has multiple roots (you mention that your problem tooth is #15), and the endodontist can determine which root lies at fault, it may be possible to cut that root off.

This isn't always possible or a good idea, your dentists will have to fill you in. But sometimes this provides a way of salvaging the work you've already had done.

Sensitivity & burning around tooth after root canal

Upon undergoing recent root canal; left upper canine, I am still experiencing a burning sensatsation along with pressure, I revisited my endo, cannot find anything even on ct scan. Could there be nerve damage or anything else lurking causing this issue? I was recently give a course of steroids which corrected the problem for about a week. Any ideas or people with similar issues?


There is neurologic condition that may persist after endodontic therapy referred to as PDAP disorder.

Obviously, we in no way know if this condition is what you are experiencing. But in terms of differential diagnosis, it seems justifiable enough that it should be considered and discussed with you by your endodontist.

Overall, we think the most important thing you can do is stay in continued contact with your endodontist. If they don't know that you're still having problems they may assume you're not, and therefore won't continue to explore possible causes and solutions. Good luck.

Gum tenderness between back lower molars

First of all I have epilepsy and since the onset of seizures - which now are very well controlled, all of my molars have had root canals and crowns. One of the meds I take is Dilantin and I floss faithfully. I noticed gum tenderness between my right lower back molars with flossing 5-7 days ago. No pain with chewing etc. This area remains tender with flossing and this evening I also have discomfort radiating to my right ear. I have also noticed some generalized aching of the area where the gum tissue is tender. I had an infected root canal on the left side 3 years ago which was a nightmare as I had a re-do root canal, new crown, then developed a draining area in my mouth a few months later, this all resulted in extraction of that molar. I am afraid of having the same senario starting again, however I remember how painful that tooth was when the infection was in there and this is not the same. Please advise—thanks!


Obviously it's going to take an evaluation by your dentist to determine what is going on. Considering that there could be infection involved with what you notice, contacting them sooner rather than later would be important. If they feel that infection is an issue, they might prescribe antibiotics for you via telephone to get that started sooner.

You mention your taking Dilantin, so what you notice (as you no doubt know) could be associated with gum tissue enlargement (hyperplasia) related to that. The scenario would be one where the situation keeps you from cleaning the area effectively, hence bacterial accumulation has started an infection. If so, it's likely that the episode could be treated and resolved.

The fact that it's not your tooth that hurts isn't a bad sign. But it's not a definitive one in ruling out the failure of a tooth's root canal treatment as being the source of your problems. (With some failed cases, it's the build up of pus in the jawbone that causes the patient's pain. If conditions exist where some of this pus has found a way to vent off, no pressure/pain may build up, but it is still the tooth's endodontic work that is the source of the problem.)

Only your dentist can make a determination between the two (or other possible causes), and only after physically examining you and likely taking x-rays of the area.


Thank you very much for your assistance! I was able to see my dentist this afternoon. The x-rays looked great which was a great relief. The gum discomfort persists however, they did try to flush the area out with a waterpik/flosser. No debris was in there, Paroex rinse was ordered and I am now using that hoping for complete relief soon. Thanks again!!


That's great

Failed root canal

I have a failed root canal then did a retreat and now I have slight swelling and pus pocket (like the pic u have of a boil) on the gum by that tooth. X-ray shows now that there is a vertical fracture on that tooth. can this tooth be saved or is the best option just to extract it and have implant there?


Generally speaking, the problem with a crack in the root of a tooth is that between the two parts there exists a space that bacteria can colonize yet your dentist can't get at them and clean them out (like they did with your tooth's root canal system).

The consequence of this scenario is that an infection will persist in the crack's space. The fact that you notice swelling associated with your tooth suggests that this is what's going on.

In that case, the tooth can't be successfully treated (the infection can't be cleared out), so extraction (with some type of artificial tooth placed, such as an implant) is the only alternative.

The single exception would be the case were the cracked (infected) root can be trimmed off (root amputation), leaving the remaining successfully root canaled/healthy portion of the tooth.

Obviously this option is only possible with multi-rooted teeth (molars, some premolars). If possible, it doesn't always make that great of a choice but it may. Only your dentist can advise you if pursuing this option makes a reasonable plan.

Failed RCRT attempt Upper Right 1 (Incisor)

Brief history:
2000 - trauma to tooth playing squash - whacked in the faced from opponents backhand racquet. Now a dead tooth.
2004 - Huge Abcess drained + RCT. Evidence of root tip absorption. 2 attempts at RCT over 3 week period.
2017 - Abcess like symptoms returned. Dentist said watch & wait. Acute swelling & mild pain subsided without use of any meds.
2018 - (2 weeks ago) - full on abcess. Drained. Evidence of further root tip absorption. Procedure involved RC re-treatment. Thought was fine but..
Last few days - new swelling. X rays show that Accessory point pushed through beyond end of root tip by a good couple of mm. Most likely from new insertion rod pushing through old debris from first RCT up into cavity. This most likely causing existing bacteria to start brewing again without interruptions!

Have been referred under 'urgent' to local Dental Hospital for Endo-treatment plan and potential Apicoectomy. In the meantime 7 day course of Antibiotics - whilst it may not end infection it'll hopefully stop it spreading further.

Prognosis not great.. Especially with old debris not in cavity space above & beyond root tip...oh dear

Root Canal and now no taste or smell

I had a root canal done on right upper back molar and ever since I have had no smell, or taste. He did not put the crown on yet. Also I have a medicine taste all the time which is affected when put certain foods in mouth. I have seen an Eye, Ear, Nose Doctor and he found nothing and the dentist says that a root canal would not cause this problem. Can you help me it has been over 6 months.


The salient point we noticed with what you stated is that you've experienced a loss of taste and smell, which are senses that are interpreted by nerves on both sides of your head (left,right), but your dental procedure only involved one side.

Anyway, we did some searching. After learning some terminology, you could no doubt find some more references. Here are one's we noticed:

This article discusses taste loss and states that it may be related to damage sustained by the chorda tympani nerve during dental procedures. (Google that nerve's location and see how that relates to the location of your tooth. The article says that aspects of the injection of dental anesthetic might be the cause of the event.)

While we don't have a link to the article itself to share, this paper is saying that they found a correlation between the loss of taste and patients that had 7 or more deafferented teeth (that means teeth extracted or treated with root canal treatment).

We didn't actually read this web page, but its title was so on target that we thought we'd share it with you:

Good luck.

Canine root canal treatment

I had a root canal treated on my upper canine. The tooth now, 4 months after procedure shows signs of failed endodoncy. The area next to nose is tender and the tooth is sensitive to horizontal percussion, vertical is fine. I discussed the issue earlier with my dentist and he offered extraction and bridge. Did not want to re endo it and said it was impossible due to the rubber filling.

Should I seek a specialist or is he correct?
Would you recommend bridge or implant as upper canine replacement? I will get crown for the surrounding teeth due to abrasion anyways.

Thank you very much for answers, this page has the best information on internet.



We can only answer your questions in general terms. And absolutely, there might be aspects of your case that are special circumstances, so our answers might not apply.

You state:
"sensitive to horizontal percussion, vertical is fine"
The usual expectation with percussion testing would be vertical sensitivity, possibly (or probably) horizontal sensitivity too. So possibly there is another issue involved with your tooth too, such as a root fracture.

You state:
"it was impossible due to the rubber filling"
No, that's not the norm. (Google: gutta percha removal endodontic retreatment)
There must be some other issue involved that complicates the removal. (Possibly the tooth has a post and core, which could make things more of a challenge.)

Consulting with an endodontist could provide an unbiased 2nd opinion, if its made clear to them that an opinion about the most satisfactory long-term outcome is the goal, and not just trying to "save" the tooth at all costs.

Choosing between a bridge vs. implant has a number of issues on its own. Due to their position in the mouth, canines are subjected to substantial forces. You also mention that your teeth have worn, so the question of excessive forces due to bruxism arises too.

And finally, sometimes the approach actually chosen is because it seems the more practical one (cost usually being the factor). Such as the case where you say neighboring teeth would be crowned anyway.

We noticed this article. It has a section about canine replacement. Note that it discusses the issue of 3 or 4 unit bridges (having the bridge just include the lateral incisor [3 unit], or also include the central incisor too [4 unit])

After Googling and reading, you should be in a better position to ask your dentist questions. Good luck.

Canine root canal treatment

Thank you for your answer. I am adding a follow up since I have seen people in two different forums complain about tenderness next to nose after maxillary canine endodoncy treatment.
My dentist took an x-ray of the tooth and it's apex ends into cavity and is not surrounded by bone which explains why the cavity that runs above it hurts when pushed against. The problem is slowly subsiding so we agreed to wait & see.

Root canal 4 and half days

Root canal 4 and half days ago. Now tooth next to it hurts. Why


That's pretty much an impossible question for a website to answer. Even your dentist would only be able to venture a guess without further chance of examination. No dental procedure comes to mind where it's normal and routine for it to cause discomfort in an uninvolved tooth.

We will say that while they didn't treat your adjacent tooth, they have no doubt seen both it and x-rays of it while performing your other tooth's treatment. That should give them some basis of insight as to what is going on.

With your status as an active patient, and a problem in the immediate area where you have just received treatment, you should feel free to contact them.

missed canal

My endodontist saw a missed canal (on 3-D) imagery. My tooth is sometimes sensitive and doesn't hurt very much. There is no sign of infection on X-ray. I wonder whether I should wait and see or get it retreated. I am worried about the 10% risk of ending up with oral surgery for a tooth that doesn't cause much problems for now. Thanks!


Our interpretation of what you state is this:

1) You have an endodontically treated tooth whose treatment has an obvious deficiency (the missed canal).
2) You have noticed symptoms with your tooth, which could easily attributed to a waxing and waning persistent infection associated with the tooth (the untreated canal).
3) The x-ray doesn't show signs of infection. (An x-ray is only able to show signs of the effect of infection going on inside a tooth on the tissues that surround its root. It isn't evidence that there is no infection inside the canal (like a low-grade one that has little effect on the tissues).).

It's easy enough to state that if the tooth's original endodontic treatment was initiated because the tooth was infected, that the untreated canal (a part of that same root canal system) would still contain bacteria and therefore the tooth is in need of retreatment to resolve that.

The problem with the "make do until it gets worse" approach is that infections are unpredictable and their flareup may be a significant event.

We would think that if your endodontist favored treatment that their opinion would be based on much of what we've stated here. And it seems a textbook approach would be that the tooth requires attention and plans should be made to go ahead and treat it.

I’m NEVER having another root canal.

I’m NEVER having another root canal. All three of mine failed when the crowns fell off, and now I have to have dental surgery on all three sites to remove the dead roots. Right now, one of the supposedly “dead” roots is killing me!!! For the cost and not to mention pain and trouble, I’m convinced implants are the way to go. No more root canals for me!!!


We're sorry to hear about your problems. It would have to be suspected/assumed that the current pain you have is due to an infection associated with the tooth. That is a condition that needs attention from your dentist, so you need to be in contact with them. That situation has the potential to worsen.

We won't try to take a position that having root canal treatment always makes the best choice. And in fact we have a page that discusses the issue of root canal treatment vs implants from a research statistics viewpoint.

From the standpoint of being a dentist, one could imagine some possible explanations for the failures. One would be if they were possibly due to the event of the crowns comming off (a problem termmed coronal leakage). If so, that would be a failure of the crown's retention, as opposed to the root canal treatment itself.

There would be other questions too, such as had just one practioner provided the work, what exactly were the circumstances associated with the crowns coming off (for example, was tooth decay involved), there could be so many other variables that might explain why the failures occurred.

So we won't concede that implants always make the better choice, but one can understand due to your experiences why you would feel that way. But for others reading, and for most cases (statistically the vast majority of cases), it still makes a good/successful choice.

Lingering post-treatment inflammation, pulp stones

Thank you for putting together such a useful and informative resource, and for taking the time to answer all the questions people ask here.

Are you aware of cases where the inflammation and discomfort after root canal treatment takes a long time to resolve (more than a month)? If so, is this more likely if there was chronic inflammation present before treatment, e.g. due to a cracked tooth?

Have you come across situations where chronic inflammation due to a cracked tooth has caused the formation of pulp stones in the opposing or nearby teeth? Have you ever heard of pulp stones themselves becoming a source of inflammation?

As you might guess, these questions stem from my own symptoms. I have discomfort and pressure sensitivity persisting more than a month after root canal treatment on #18 (for a small crack above the gumline; there was inflammation, but it had not progressed to infection). Follow-up x-rays don't show any signs of infection, but did reveal pulp stones in #14 and #15.


>>Are you aware of cases where the inflammation and discomfort after root canal treatment takes a long time to resolve (more than a month)?

We have a number of pages that discuss complications and treatment failures. Scroll up this page, you'll find the menu of this topic's pages.

>>If so, is this more likely if there was chronic inflammation present before treatment, e.g. due to a cracked tooth?

The presence and magnitude of preoperative apical periodontitis seems to correlate with a poorer case prognosis. With apical periodontitis being caused by infection of the root canal system by microorganisms. We're not so sure this definition is the same as what you mention.

>>Have you come across situations where chronic inflammation due to a cracked tooth has caused the formation of pulp stones in the opposing or nearby teeth? Have you ever heard of pulp stones themselves becoming a source of inflammation?

The presence of pulp stone is not rare.

Here's from Cohen's textbook of endodontics:
"There is no clear evidence whether pulp calcification is a pathologic process related to various forms of injury or a natural phenomenon. The clinical significance of pulp calcification is that it may hinder root canal treatment."
"Therefore, from a clinical perspective, it would be very unlikely that a patient’s unexplained
pain symptoms are due to pulpal calcifications, no matter how dramatic they may appear on a radiograph."

Here's from Ingle's textbook of endodontics:
"Discrete pulp stones are not considered pathologic. Their only clinical significance is that they can add to the adventure of locating and instrumenting root canals."

Both of these books are listed as references for this page above.

>>I have discomfort and pressure sensitivity persisting more than a month after root canal treatment on #18 (for a small crack above the gumline; there was inflammation, but it had not progressed to infection).

A scenario could be where the crack is more extensive initially thought. Or has progressed since the time of the treatment (timing of final restoration, type of final restoration, see menu above).

Thank you for your detailed

Thank you for your detailed and thoughtful response.

My dentist and endodontist continue to investigate, but their diagnostics are inconclusive so far. Hopefully they will figure it out soon.

Tooth still tender to horizontal pressure four months after RCT

In January, I had a root canal of the next-to-last molar on my lower right. It is still very tender to pressure from the front, even a slight touch, but there is no tenderness if I press down or from the back. A permanent zirconia crown as placed about six weeks after the procedure. X-rays look fine, dentist says she sees no problem. There was, as far as I know, never any infection. Apparently an old filling had come out, the interior of the tooth had become sensitive, and I went to her in January, when she did the root canal. Before the root canal, there was no percussion or pressure pain involved, only since. There is no hot or cold sensitivity, and hasn’t been since the RCT. She tested as best one can for fracture, and seems to think that is not the problem.
What can I do? The tooth is rarely painful by itself, only when I touch it from the front. Should I go to an endodontist?
The problem has not got any worse over these four months, but I don’t think it


We're not going to have any special insight to offer.

Yes, with cases that are difficult to diagnose referral to an endodontist is common.
They may not have any definitive answers or solution for you either but that is the next level of authority to turn to (more expertise with problem cases, more sophisticated imaging). Doing so seems reasonable enough in light of the fact that your tooth is not asymptomatic months out and your dentist has no theory or solution to offer.

The only other alternative is to do nothing (wait-and-see approach), which with some scenarios could place you at risk for an acute tooth flareup. If that approach seems reasonable and is taken, you should discussed with your dentist what plan is in place if per chance a turn for the worse occurs.

One might anticipate that the conditions associated with this event "The tooth is rarely painful by itself" (spontaneous pain, in response to an event, etc...) might help with the diagnosis.

Cracked Root

I had a root canal done on a lower molar and have had issues with a "gum boil" on the side, my dentist advised that I cracked the root, (probably due to grinding my teeth while I sleep) and that I would need to get the tooth I had already invested a lot of money into saving extracted. Any advise for me on how to afford extracting and restoring a tooth I already invested $1500 to save?


As you probably know, the gum boil you mention is often a sign of infection associated with a tooth. In your case, one where bacteria live in the space between the two broken portions.
Bacteria can be removed from root canals because instruments can be worked down them.
In the case of a crack, there are no tools that can negotiate that type of space, thus the infection/bacteria can't be cleared up.
That is why your dentist has recommended tooth extraction.

Lower molars are two-rooted teeth.
If your dentist feels confident about which root is cracked (the position of the gum boil might identify this), it's conceivable that that root can be cut off (root amputation).

There are a lot of associated issues:
Does the dentist have adequate access to be able to perform the surgery/remove the root?
Are the molar's roots entirely separate or fused?
Considering the amount of chewing forces involved, with just one root can the tooth adequately withstand them? (If not, it will loosen and/or shift over time.)
After the root amputation, will architecture of gums be such that the tooth and/or neighboring teeth can be cleansed properly (so to avoid gum disease or decay)?
If you have an existing crown, can it be retained (probably not ideal) or will a new one need to be made?
(Actually, if the tooth doesn't already have a crown, it makes the possibility of a successful root amputation scenario taking place. Better access, more options.)

It's not all that often when all of these conditions can be met.
And while not rare, using this route is not all that common either.
But your only hope of making a go of a tooth with a cracked root will need to involve root amputation, so ask about that possibility.

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