Why does my root canal tooth still hurt?

My dentist placed three new crowns in August. One crown is on my bottom left, second molar tooth, a second is on my top left, first molar tooth, and the third is on the second molar tooth. The bottom tooth hurt, so my dentist gave it a little time and decided to do a root canal. I got the root canal two weeks ago, but my tooth still hurts. I am almost finished taking the antibiotic. Should I wait until I finish the medication before calling my dentist and scheduling with her? How long should a root canal tooth hurt? – Thanks for your help. Teri from Pittsburgh, PA


Thank you for choosing our office for your question.

One of our dentists would need to examine your tooth and x-rays for an accurate diagnosis. And the dentist would ask more questions, including:

  • Has the pain increased or decreased since root canal therapy?
  • What triggers the pain?
  • Is your tooth sensitive?

Causes of Ongoing Pain After Root Canal Therapy

Diagram with five states of root canal treatment
Root canal therapy must clean infection from all canals
  • Untreated root canals – Although most molar teeth have three canals, sometimes a tooth has four or five canals. If your dentist misses them and does not treat the infection, the pain will persist.
  • Problem with another tooth – If another tooth is infected, the pain can refer to other teeth.
  • Inflammation – Sometimes, after root canal treatment, a tooth may be inflamed and sensitive. When you bite or chew on that side, the irritation causes post-operative pain. It can take a while for the tooth to get better. Some dentists make a thin mouth guard for you to wear at night and when you are not eating to relieve the pressure on the affected tooth.
  • Irritation from crown preparation– Sometimes, preparing your tooth for a dental crown and removing some tooth structure irritates it. But it should decrease over time.

Rather than wait until you have taken all the antibiotic medication, call your dentist and ask for an x-ray to ensure she treated all the canals. If necessary, your dentist can refer you to a root canal specialist.

Burba Dental Partners of Salem, Massachusetts, sponsors this post. Our patients say we offer some of the best dental care in the Boston area.

My Perforated Sinus Is Still Infected After Antibiotics

Three days after wisdom teeth extraction, the swelling in my cheek increased. I also had yellow discharge coming from the sockets and my nose. I called the oral surgeon’s office and was prescribed Augmentin for a minor sinus perforation. Although the facial swelling decreased, a CT scan showed that one sinus is still infected.

Woman holding her upper nose, perhaps with a perforated sinus and infection - for information from Burba Dental in the Boston, MA area

Then the surgeon prescribed Azithromycin for five days. It’s almost a week since I finished the Azithronycin, but I still have drainage from the sinus hole, although it is a little better. I also feel slight pain and pressure in my sinus. The surgeon asked me to irrigate my gums with a prescription rinse and use Flonase for the sinus. I still feel pressure and some pain in the sinus. Does it sound like the sinus is healing, or do I need to schedule an appointment with an ear, nose, and throat specialist? Thank you. ~ Traci


Thank you for your questions.

One of our dentists would need to examine you for an accurate diagnosis, but we will offer some insight based on your description.

Sinus perforation does not usually cause an infection. But an infected tooth can leave bacteria behind after extraction that gets pushed into the sinus. The oral surgeon prescribed Augmentin for the condition that caused facial swelling and Azithromycin for the sinus infection. It seems that your CT scan did not show any fragments in your sinus that are slowing the healing process or require removal.

Lingering Sinus Infection After Finishing Antibiotics

If you finished the Azithromycin yet still feel pain and pressure in your sinus, you probably need a refill. You should continue an antibiotic until the infection is gone to prevent antibiotic resistance.

Flonase is a corticosteroid for reducing inflammation and should decrease pressure in your sinus over time. Although we do not have all the details about your case or your dental records, it seems that your oral surgeon has the issue under control. You do not need to see an ENT, but you should call the oral surgeon to explain that the infection is lingering, and you may need another antibiotic prescription.

Best wishes for a steady recovery.

Burba Dental Partners of Salem, MA, sponsors this post. Please read what our doctors do to provide some of the best dental care in the Boston area.

My New Crowns Hurt When I Chew. Should I Ask for New Ones?

Man with expression of uncertainty perhaps from new crowns that hurt and create TMJ issues

Two months ago, my dentist placed crowns on my top left second bicuspid, first molar, and second molar. I do not have any wisdom teeth left. I had deep decay and old fillings on all three teeth. At least two of the teeth hurt when I chew on that side of my mouth.

New crowns on three teeth in a row make it hard to tell where the pain is coming from. When I put pressure on the three teeth with my finger, two seem to hurt more than the others.

My dentist adjusted the crowns twice but said that I have an aggressive bite when I chew. He suggested alternating chewing on the left and right sides of my mouth. I disagree with him because I did not have the problem before getting new crowns. The pain almost feels like nerve exposure. Should I ask for new crowns?

Thank you for your question.

Based on your description, it does not seem that the problem may be related to your bite (the way your upper and lower teeth fit together) rather than the new crowns.

Why Do Your New Back-Teeth Crowns Hurt?

If your new back-teeth crowns hurt when chewing, two possible causes are the bite is too high or one or more teeth are infected.

  • Adjusting your bite – When your bite is too high, the lower teeth hit the crowned teeth harder than the other. The repetitive wills make the teeth sensitive. Over time, your jaw muscles and joints can become irritated and sore. You may also experience neck pain, earaches, or headaches. These symptoms are related to TMJ disorder. But if your dentist adjusted your bite twice, an infection may be the issue.
  • Tooth infection – Your dentist can take x-rays to see if any of your problem teeth are infected. Sometimes signs of tooth infection are subtle and require a root canal specialist’s skill (endodontist). The intensity of your pain sounds like you may need root canal treatment.

Will You Need New Crowns After Root Canal Treatment?

An endodontist can make an opening through your new crowns to perform root canal treatment. You will only need new crowns if your current crowns are defective or contributing to your tooth irritation.

Cosmetic dentists Dr. Randy Burba and Dr. Stanley Burba in Salem, Massachusetts, sponsor this post.