Complications and Care After Root Canal Therapy

These days dentists prefer doing single sitting root canal treatment in which, after the diagnosis is made, in single visit the root canal treatment (RCT) is completed. After the root canal treatment, the patient can have few problems like pain after procedure, swelling after root canal treatment, Fracture of root canal treated tooth, discoloration of tooth after root canal. Incomplete filling, missing of a canal or breakage of instrument can also occur during root canal treatment and can cause complications later on. In case of failure of root canal treatment, root canal re-treatment, Apicoectomy or tooth extraction is done.

1. Pain after Root Canal Treatment: If root canal treatment is done when first indicated, then patient usually get immediate relief from symptoms after procedure. If there was severe infection in tooth before root canal treatment, then patient may experience some moderate pain after procedure. There can be pain after the affect of numbness is over. One can take a pain killer which is normally prescribed by the dentist. If pain is acute and there is swelling then one should consult the dentist. Mild soft tissue inflammation is there which causes irritation but it subsides within a week after the root canal treatment. Antibiotics may or may not be prescribed after root canal procedure. If patient experiences pain after few months of root canal treatment and there is difficulty in chewing then the dentist has to be consulted because some times the infection is left or the filling is not done properly and it causes the pain. In such cases some times root canal re-treatment is recommended. But the diagnosis has to be made after taking the proper history, clinical examination and with x-rays.

Medication after root canal therapy:

a. 600 mg dose of ibuprofen which is available OTC (Motrin, Advil) within 4 hours after root canal treatment is performed. Dose should not exceed 800mg. Dentist may also prescribe oxaprozin or ketorolac (Prescription only) after root canal treatment. Codeine is given in case of severe pain and has to be used for short term. Pain meds will provide relief and will reduce the swelling.

b. Amoxicillin or clindamycin antibiotic may also be given after root canal therapy.

When to consult a dentist or endodontist
If pain is acute or if pain persists for more than 2weeks, then patient should visit his dentist to get the root canal treated tooth evaluated. Pain persisting for long time can be because of root canal failure.

2. Swelling after root canal treatment: Swelling is one of the possible complications which can occur after root canal treatment. To reduce swelling after root canal treatment, anti-inflammatory meds are given. Swelling which doesn’t regress after some time can be because of faulty root canal therapy procedure, re-infection of root canals. To treat swelling after root canal treatment, cause of swelling is diagnosed and treatment is provided accordingly.If some teeth feel higher than other teeth, then patient can call his dentist or endodontist who can adjust the bite.

3. Fracture of the Tooth: It is advisable to go for crowning of the tooth after the root canal treatment as the tooth becomes brittle and is prone to fracture. The crown will save the tooth structure and gives natural feeling. Dental crown is given after root canal treatment to provide strength to the weak and brittle root canal treated tooth and to hide the discoloration which may occur at times after root canal treatment.

4. Discoloration of the Tooth: After the root canal treatment as the tooth looses its vitality, it becomes discolored. This discoloration can be taken care of either by bleaching or by giving dental crown on root canal treated tooth.

5. Breakage of instrument during cleaning and shaping of canals: The dental files or other instruments used in the cleaning and shaping of the pulp space might break down and cause complication. Broken file can be removed by an Endodontist who is specialist in root canal treatment. If the root canals are cleaned and sterilized before the endodontic file gets broken, then broken file doesn’t usually cause any symptoms. If canals are not sterilized before dental file is broken, then leaving broken file in the canal can cause problems like root canal failure and can even act as source of infection later on.

6. Incomplete filling or missing a canal: Incomplete filling or missing a canal while filling may act as a source of retained infection or new infection. All this leads to treatment failure and aggravates the complications.

Certain bacteria are not responsive to root canal treatment to a great extent enhancing the problems.

Care after Root Canal Treatment

1. Patient should avoid eating from side of root canal treated tooth.
2. To reduce swelling after root canal treatment, ice pack application over that area can be done. Ice pack application should be done for 10-15 minutes every hour.
3. Take the pain meds as directed and complete the course of antibiotics. Pain meds should be taken before the effect of local anesthesia wears off.
4. Patient should sleep with head at slightly elevated position.
5. Patient should take soft foods at least for 2 days after root canal treatment. Very hot or cold foods should be avoided after root canal treatment.
6. Avoid smoking, drinking or stressful exercises as it will affect the healing.

What to do if root canal treatment fails

In case of root canal failure, root canal re-treatment, Apicoectomy or tooth extraction is done. Root canal re-treatment and Apicoectomy is done to save the tooth and to remove the infection from the tooth. Procedure for root canal re-treatment is similar to root canal treatment and is mainly performed by endodontist. Apicoectomy is surgical removal of root apex to remove infection. If prognosis of root canal re-treatment or Apicoectomy is poor, then tooth extraction may also be required. After tooth extraction, patient can get the missing tooth replaced with either dental implants or dental bridge.

Whether all the teeth which have pain can be saved by the root canal treatment?

The answer is No, for the success of root canal treatment the careful selection of the case is very important. All the teeth can not be treated by root canal treatment. There are few conditions in which the teeth can not be treated with root canal treatment:

1. When the tooth in question does not have adequate bone support and the bone supporting the tooth shows resorption and tooth is mobile, then that tooth cannot be saved by root canal treatment.
2. When the tooth which has to be treated by root canal treatment has inadequate tooth structure and can not be restored after wards
3. When the general resistance of the patient is poor in that case root canal treatment is not indicated.
4. If the root is fractured then also the tooth cannot be saved by root canal treatment.


 User Comments on -  Complications and Care After Root Canal Therapy

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Posted By : dr ashfaq shaikh on 22-Apr-2015 11:23 AM
last week my wife had root canal treatment done for her left upper and lower pre-molar teeth after she started experiencing sever pain in her left TM joint with inability to open her mouth not more than an inch. kindly advice what should be done. do we need to visit the dentist again or hot fomentation is sufficient. thanks.

Posted By : Jaya Samuel on 07-May-2014 03:16 PM
On 3-5-2014 I went to a dentist for dental check up. He said that 2 of my teeth need RCT. I agreed to it. No Antibiotics were given to me before or immediately after the RCT. On Monday, 5-5-2014, I felt severe pain and swelling of the left side of my face. When contacted, the Dentist prescribed antibiotics (Amoxycillin and Potassium Clavulanate Tabs 650) and Combiflam tab. The swelling increased and pain also increased. On 7-5-2014, the Dentist prescribed the same tablets of 1000g. Still the pain and swelling did not come down. Kindly advice.

Posted By : Maria Hendon on 04-May-2014 06:20 PM
After a apicoectomy in December, a RCT in December and another apicoectomy in April- I am still having some numbness and pain but most of all- there is a really foul taste, somewhat metallic in my mouth. Had 3-4 rounds of antibiotics throughout the procedures. Can handle everything except for the bad taste- what is it and why wont it go away?

Posted By : Dr. Ritz on 30-Oct-2013 08:26 PM
Dr. Mark Mancin The post operative sensitivity is either because of over instrumentation or it can be due to pulpal remants either in the main canal or some accessory canal. For this you can put the medicament in the canal and wait for few days before going for obturation.

Posted By : Dr. Mark Mancin on 24-Oct-2013 11:58 AM
Dear Doctor! I had a patient who requited RCT on #2. She had a previous large area of buccal decay and a filling was done in this area ~ 1 year ago. The tooth became symptomatic and painful requiring RCT to relieve her pain. The RCT was straight forward; pulpal contents were removed, irrigated thoroughly and medicament placed with pellet and temp filling. Approximately 24 hours later the patient experienced a strong throbbing sensation in the tooth that woke her at night. She received minor relief with NSAI's and/or Vicoprofen. She presented today with the throbbing sensation in the UR area. Before anesthesia I reverified that the discomfort was coming from this tooth. I then gave her a PSA injection only to once again verify that #2 was the cause. She got relief but not 100% relief. She still felt a dull ache in the tooth with most of it coming from the palatal area upon testing. A palatal injection was given and she experienced immediate relief. We placed the rubber dam, removed the temp filling and pellet. The pellet showed on signs of blood and/or infection. The medicament was flushed and paper points were placed down the 3 canals and once again no sign of infection or blood was noted. I reverifed the working length both with apex locator and x-ray. Please note the canals are located within the sinus cavity. She had been experiencing some right sided sinus problems prior to the RCT and after. Upon filing the canals the MB and DB were WNL. The palatal canal hurt upon placement of the file at the apex and upon withdrawal of the file (hand file)from the apex towards the coronal portion of the tooth. She described it as being electrical in nature. She is so uncomfortable she wants the tooth out! I relieved the occlusion so she in not touching the opposing teeth. She said it hurts to place her tongue up against the tooth. I am at loss as to why this is happening. Additionally a root fracture has been ruled out. What could be causing this post operative hypersensitivity??? Any help would be greatly appreciated...Dr. Mark S. Mancin

Posted By : Carrie on 23-Oct-2013 02:06 PM
I had a root canal about 2 years ago with many complications. The tooth was severely infected and not treated prior to work being done. It was so painful staff had to hold me still and it took several hours during several appointments. I went to a second dentist in which I was told it shouldn't have hurt and the infection should have been addressed before hand. Also, that part of file had broke and was left. Now, two years latter, it feels infected. I do have an appointment with my new dentist next week, however Im concerned Ill have to have it redone. In which I paid a couple grand the first time, certainly cant afford to do it again. My question is, should the original dentist be responsible for a refund or is this common and something that could be expected? It has been an awful experience all around! Any advise? Thanks!

Posted By : Dr.Ritz on 12-Oct-2012 03:40 AM

Hi GINGER,Severe pain and tenderness on biting indicate that the root canal might be failing.I would suggest you to examine the patient's gums around the tooth for swelling or discoloration.Inflamed gums are often the most prominent sign of a failed root canal, as they may mean that the bacteria and decay are continuing to irritate the surrounding tissue.Also,take a new series of x-rays.Generally, changes will appear from one set of x-rays to the next if the root canal has failed.If you feel re rct is required,start off as soon as possible to relieve patient's pain and tenderness.Keep us updated.Good luck!


Posted By : Ginger DMD on 11-Oct-2012 10:50 PM
a patient came to me with severe pain on lowere left first premolar. tooth with Cl.II amalgam restoration. tooth had undegone RCT in 1991. Gave him cefalexin 500mg TID for 5 days and mefenamic acid for pain. Patient was told to come back 3 days after. Patient still with pain, yunable to sleep well and tenderness on biting. On his next visit, i intend to open the canal and redo the RCT. your comment please, thanks

Posted By : Dr.Ritz on 17-Sep-2012 10:59 PM

Hi Yoli, Can you please tell us your query in detail as the dentists are not able to evaluate your problem.


Posted By : Yoli on 17-Sep-2012 03:21 PM
Gracias for the advice. I will seek a secound opinion, although the person who is seeing me is a Endodontis... But he has no send me antibiotics or antiflamatory tables & today I am in pain after seeing him on Friday. Thanks again... I will search for another specialist in my area. Yoli

Posted By : Dr.Ritz on 14-Sep-2012 09:45 PM

Hi YOLI,Swelling in the tooth can be because of over filling of the canals or can be because of perforation of canals during root canal procedure or can be because of infection still left in root canal treated tooth. Overfilling of canals may cause development of fistula on gum adjacent to tooth and cause infection.Only taking antibiotics and pain medicines may not solve the problem.If there is infection still left in the tooth which can be confirmed an x-ray you may have to go for apicoectomy(surgical removal of root apex).Without clinical examination,it is difficult to give a definite diagnosis.You can refer to an endodontist who is specialist in root canal treatment for a second opinion.He will evaluate the condition of the tooth and will decide that whether tooth can be saved or not. If he thinks that prognosis of tooth after apicoectomy is not good, then he will pull the tooth out.For the time being, for some relief, you can avoid eating from that side of the tooth and take the medicines as prescribed by your dentist.As there is swelling present in that area,you can do warm saline rinses for some relief.I hope that helps.Let me know if you any other queries.Thanks for the comment.Good luck with your tooth!!


Posted By : Yoli on 14-Sep-2012 09:03 AM
Hi, I have been having RCT now for 3 months. The first one was a re-root. Then, the swelling did no go and I was told it was the tooth behind and then we did that treatment. That was in July ( last one) I still swellen and going to dentist every 10 days. I am starting to lose confident whether the man knows what he is doing. Do you think I own to see someone else. I am fed up of going to dentist and I want to have this sorted.

Posted By : Dr.Ritz on 07-Sep-2012 11:57 PM

Dear KEVIN,As your dentist said,sometimes it is necessary to leave the canals open for some time so as to ensure that all the pus and suspected infection drains out.During this period,you can avoid any kind of infection by taking antibiotics as prescribed by your dentist and maintaining good oral hygiene.Brush your teeth twice daily.You can also use mouthwash to prevent food accumulation in the involved area.Warm saline rinses will also be benefecial.


Posted By : Kevin on 07-Sep-2012 06:37 AM
Hi, about 12 years ago, I fell whilst playing basketball and my two front teeth chipped. I have since had root canal treatment on them. A few weeks ago, i noticed two pimples on my gums directly above the affected teeth, went to see my dentist and she diagnosed that my previous root canal treatment was not completed properly. She therefore redid the RCT but says she needs to leave the canals open for the next three weeks so as to ensure that all the pus and suspected infection drains out. I feel absolutely no pain at all, just some pain during the RCT procedure as it was done with no anaesthesia. I am worried that if I stay for too long (3 weeks) with open canals, i may be at a higher risk of infection. Please help.

Posted By : Dr.Ritz on 04-Sep-2012 01:09 AM

Dear HUDSONGRL,The intermittent pain experienced by you can be due to trismus as your dentists say that Rcts are fine.You can do mouth exercises by putting 3 fingers in mouth and try to open your mouth. Soreness and jaw pain will be fine in some time.Trismus takes 2-3 months to resolve completely.Consult oro facial pain specialist if pain persists.


Posted By : Hudsongrl on 03-Sep-2012 01:45 PM
In mid May I had a root canal done on #31. All went well and pain subsided and I thought I was good to go. But, On July 8th I started having pain on an upper tooth, #2. Endodontist said the tooth was dying ( used cold test) and it also needed a root canal. This one did not go smoothly. I had a huge problem with novacaine injections and ended up with large hematoma, bruising and subsequent trismus. I have been using hot compresses, taking advil and doing stretching exercises to releive the trismus. Have been in several times for bite adjustments to the permanent fillings. ( Both teeth treated with RCT already had crowns). It seems I am slowly getting better, but I do not feel that #31 feels right. It is intermittently tender. And I feel like I am hitting it sometimes when i bite it is high. Articulating paper show it is no longer high. I have seen my endo and regular dentist who have taken new x-rays and tell me both RCT look text book fine. Can the intermittent pain I am feeling be caused by the trismus as those muscles are still very tightand pain radiates down my jaw and sometimes into my ear. They think I should give the trismus more time to completely resolve ( i would say it is 80% better) and if no resolution in another few weeks, see an oral facial pain specialist. What do you think?

Posted By : Dr.Ritz on 19-Aug-2012 11:19 PM

Dear AMIR, Thanks for such a nice info. We would like to hear more from your side in future.


Posted By : Dr.Ritz on 19-Aug-2012 10:12 PM

Dear TERESA, The symptoms mentioned by you can have three possibilities:

1. You nerve might have got punctured accidently the time dentist was giving you anesthesia. You don't need to worry about this as the nerve will recover within two weeks.

2. Local anesthesia when given in excess are toxic. Thought LA at greater concentration is increases the effectivity but also increases the toxicity levels i.e. numbness. So, i feel that the numbness is due to increases amount of anesthesia injected into the site.

3. Gutta Percha is used to fill the prepared root canals but if they are filled in excess then it leads to post op numbness and pain in jaw. Reason being they contains harmful para formaldehyde which at excessive levels are toxic.

So, I would suggest you to complete the course of medications and do warm saline gargles 3-4 times daily. The problem will be resolved by a week.


Posted By : Amir on 19-Aug-2012 01:09 AM
Clindomycine is not sufficient and appropriate as antibiotic for the case of most root canal infections. Because bacteria is aneorobic. You should use Metronidazole along with Clindo and you will see the effect in 48 hours. The pain and infection will fade awy. Only Clindo can not help for sure

Posted By : Teresa on 18-Aug-2012 06:02 AM
Ten days ago I went to dentist with an abscessed tooth he did a root canal and gave me script for penicillin and pain pills then sent me home. I was in severe pain. Two day later I went back I was in horrific pain they put me on antibotics. Not to mention my mouth was still numb face swollen and a ball like at my jaw. The dentist said he didn't hit a nerve and that the abscess was in my jawbone. Four days after that I'm still in severe pain still numb and still swollen so I went back and he did xray and said it showed the abscess was gone but he had no idea why I was still numb and still swollen. He said to come back in 3 days and if it wasn't a hundred percent he would take my tooth out cause he didn't know what else to do. I called him on that day and told him it was a littl better but still numb and still a little swollen and that I had taken all my medicine and I thought maybe I needed more antibotics to finish heeling it. He said he would call them in but didnt and they are closed weekends. I'm really worried with it still numb and still a little knot and my jaw and still a little swollen and sore up to my ear. This was done on the bottom right side of my mouth in the middle. Thanks Teresa

Posted By : Ginger on 17-Aug-2012 05:53 PM
Hi, about 20yrs. ago I had a crown put on my upper right tooth the second behind the canine, no root canal, the dentist crowned it cuz it had a big filling. 4 yrs. ago it would flair up and hurt and sometimes the roof of my mouth would swell, dentist I was seeing at the time said nothing wrong with it, but said tooth in front of it needed RTC and crown, did that but tooth would still flair up from time to time. August 1st was eating and this tooth broke off at the gum, no pain though,called another dentist and he saw me the next day, said the tooth could be saved, but it had infection, I am allergic to penicillin, so prescribed clindamycin 300mg 4x day...and said he would have to do root canal then to save the tooth. Next day I was in severe pain, next day some swelling..finished the clindamycin, and went in the following week, still some infection, he said it could take a while before it is completely gone and recommended waiting another week, just went in today, and he decided it may need to be pulled, we are trying another week of clindamycin and I go back in next Friday, and he may pull the tooth. My question, if I am on these antibiotics, why is infection still there? Also is it safe to pull this tooth if I still have infection next week when I go? I am scared of this infection, friends keep telling me it could go to my heart, can it do this if I am on the clindamycin?

Posted By : Dr.Ritz on 16-Aug-2012 10:18 PM

Dear ELEANOR, After RCT,though there is pain for couple of days but having pain after such a long time is not acceptable. the only reason behind pain might be infection still inside the tooth. So, i would suggest you to visit a dentist and get an Xray done to see the cause and also you can get your permanent filling removed. It will provide you with some relief as this will ease some pressure off the tooth.


Posted By : eleanor elliott on 16-Aug-2012 09:48 AM
pain in root canal tooth 2 weeks after. I have had the pernmanent filling and have been on antibiotics for 7 days. I told the dentist that there was pain in tooth but she said impossible and drilled out temperary filling with no freezing. It did not hurt then. That was 2 days ago. Now I am in horrible pain. What is wrong

Posted By : Dr.Ritz on 16-Aug-2012 01:24 AM

Dear LINDA, Though your case requires a clinical evaluation but what i feel is that you are having an infection left inside the tooth. Did your dentist took an Xray before starting with the RCT or before diagnosing the problem. So, i would advise you to get an X-ray done first and revert back to us with the findings in your Xray.


Posted By : Dr.Ritz on 15-Aug-2012 11:53 PM

Dear LEX, In whole of your question you didn't mention regarding Xrays or OPG. Did your dentist took an Xray after you suffered a trauma as any pain after RCT should first be treated with an Xray. Since your pain started only after trauma to the tooth so, what i have diagnosed is that root fracture is the only cause behind all your problems and getting a poorly fitting crown (as you said that there was gap between adjacent tooth)aggravated your condition. Now you need to be extra precautious regarding the bridges and complete your course of medications along with regular follow ups till the problem subsides.


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