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Dentistry/Root Canal Possible reinfection


I have a general dentist whom I like, and is generally attentive. However, I have had intermittent pain in my right front upper teeth (around teeth 3 to 6)for a very long time and he cannot seem to locate the source. Along with the pain, comes sinus pain, sometimes accompanied by discharge from my nose. The sinus issues generally respond well to antibiotics.  Sometimes, if I run my finger along that side of my palate, a very unpleasant odor comes off, but does not come off other areas of my mouth.  I have been to a number of ENTs and Oral Surgeons, as well as my GP and none of them can find anything wrong with sinuses. I have had two scopes done at the ENT and two MRIs of sinus. I do not have allergies or a history of sinus problems until the past few years, and I rarely get colds. Our last effort at the dentist was to place a sedative filling in tooth 5 for a few months, then fill it with a regular filling. The pain continues.

I have asked my dentist on many occasions if the pain could come from tooth #4, which had a root canal and crown about 15 years ago. My dentist insists I cannot possibly feel pain in a tooth that has a root canal. I asked, if it can't feel pain, how would one know if a root canal tooth "went bad".  He said it would most definitely show on an x-ray and there definitely be an abscess.  I understand the actual tooth cannot feel pain, but the tissue around the tooth is very sensitive. The last time we had this conversation he said (rather dismissively) "well, the gums probably hurt because they need to be cleaned or something is irritating it". I'd had a cleaning done in his office the week prior. I am a very conscientious cleaner and flosser of my teeth.

Should it not be a cause for concern for my dentist that the tissue around the tooth grows irritated, or that the sinus infections always occur with corresponding dental pain, always on that side of my mouth?  The pain is very frustrating, and can become debilitating. It causes me horrible headaches and often will not clear without antibiotics. I dislike taking antibiotics repeatedly, as I know it's not good for me and not good for the effectiveness of these medications in general. I would much rather have the issue resolved.

My question(s):
Is it possible for a root canal to become reinfected without a "textbook" presentation such as abscess, or perhaps not be visible on an Xray? Is there any other way to tell?   

Do you have any recommendations how I could address this problem and identify or rule out the reinfection of the tooth with the root canal?
Thank you for taking the time to read this. I appreciate any input you can provide!

ANSWER: Hi Denise,

Before I try to help, could you please describe your pain? Hot/cold sensitive, sore to chew, biting tender, throbbing, burning, any other things to help me decipher your pain.


Gary Backlund DMD, MSD

---------- FOLLOW-UP ----------

QUESTION: Hi Dr. Backlund- In response to your question about the pain.  It is hard to pinpoint where exactly the pain is located. THe pain is definitely ache. Steady pain, soreness, no throbbing or burning.  Sometimes it aches all along my teeth, with particular soreness on tooth 4 and 5.  Sometimes it aches just above the tooth. Sometimes it aches and aches until it feels like all my teeth, and my ear and my face hurt, and I get a bad headache.  

There was previously no pain with heat or cold or tapping before, but  in the few days since I had the last filling done and wrote you, I now have actual shooting pain when I floss the front side of the tooth with the new filling, and sensitivity to cold, which is new.

Thank you for your response nd your patience

ANSWER: Hi again Denise,

Thank you for helping. It certainly helps some, but I'm afraid to say that without being able to exam you, I really can't diagnosis your problem. However, I can try to answer your questions.

First, it is definitely possible for a root canal to fail and not show up on an Xray. X-rays only show bone that has been destroyed and in a full blown abscess, we usually see a dark area of destroyed bone around the end of the tooth. After a root canal is done, this bone will heal back in which is how we evaluate healing. However, in the early stages of problems, there may not be enough bone destroyed to show up on an Xray or the problem with the root canal may not even destroy bone, like a vertical fracture. X-rays are still our best source for diagnosis, but sometimes we need to think outside the box. That said, I can also tell you that more is going on than just the root canal. The fact that cold has become a factor tells me we are dealing with another tooth. After a root canal has been done, it is impossible for that tooth to feel hot or cold since the nerve has been removed. Even if the root canal has been done poorly and fails, it will still not be temperature sensitive. Also, the situation with your gums is not typical of a root canal problem. We just don't see that when a root canal fails. It could be that tooth #5 is part of the problem still and may have been all along.

I would suggest that you ask for a referral to an endodontist for examination and a 2nd opinion. We specialize in pain diagnosis as well as doing root canals. That will give you a chance to get the root canal evaluated by a different set of eyes and also to get another opinion about all that has been going on in this area. With all that is going on and what you have been through, it sounds like a reasonable next step.

I hope this helps some at least. Please let me know what you find out. I'm curious.

Gary Backlund DMD, MSD

---------- FOLLOW-UP ----------

QUESTION: I am just writing to thank you belatedly for what is possibly the best, most thorough and sympathetic response I have ever received on this forum!  If you respond, I will rate you, as it appears the option to give a rating has disappeared due to the late response by myself.

I have been to an endodontist and he stated I needed a root canal in #4, but he did not show me the xray and his receptionist was quoting me prices for a root canal before he even examined me, so I felt a little hesitant to jump into a root canal. When I went back to the general dentist he stated that he doesn't see any abcess so I'm at square one. I still have sensitivity to cold, pain on biting now, and strangely a bit of pain when I blow my nose. I have an appointment to see another general dentist, who I plan to just tell I have pain on right side that I can't pinpoint, and not give him a history until he's had a chance to form his own opinion. I will try to let you know what he finds.   Thanks again, very kindly for your response.

Good morning Denise,

Thank you SO much for the kind's really the only "payment" I get for volunteering and your words mean a lot! Glad I was some help.

My only comment would be that with the problem you are having, I would really suggest seeing another endodontist, if that is possible. I'm sorry you had a bad experience with the first one because that is not the way most of us practice. When you have a complicated situation, like you do, most general dentists just don't see that many difficult cases. As specialists, we are referred all the tough ones, so I see more diagnosis problems in one year than most general dentists see in a lifetime.

Please let me know what you find out as I'm still curious.

Best regards and thanks again!

Gary Backlund DMD, MSD


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Gary Backlund, DMD, MSD


I am an Endodontist ( root canal specialist ) and can answer questions about root canals and their treatment. I cannot diagnose or treat online, but can answer general questions. I have been a specialist for 25 years and am Past President of the Washington State Association of Endodontists.


25 years practicing as a specialist

American Association of Endodonists, Past President Washington State Association of Endodontists.

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