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Dentistry/tooth sensitivity to cold after fillings, but in a different tooth


I have been getting various kinds of work done on my teeth lately.  I had a root canal done about a month ago, and that isn't causing much trouble, though it did get infected a few times.  It has been fine for the past few weeks.
I had a few cavities filled (silver fillings) in my molars on the upper right-hand side of my mouth and the upper left-hand side of my mouth.  I have an appointment this week to get more filled on the bottom right-hand side.  My dentist did not say I had any cavities in the lower left-hand side; however, that is where I have been having the most pain lately.  My teeth are horribly sensitive to cold foods and drinks, as well as sweets.  The pain is throbbing, radiating through most of my mouth at times, and lasts a good 20 minutes after cold food/beverage touches it.  The funny thing is, my dentist told me that there is one filled cavity that might need a root canal because it was deep, but this tooth hurts the least out of all of them.  All of the the filled cavities are sensitive to cold, but not as badly as the tooth that apparently has nothing wrong with it.
It has only been about a week since my last fillings were done and since the pain started... what could this be?  Do I need another root canal in the lower left molar even though my dentist says there doesn't seem to be anything wrong with it?  I have also had swollen glands and a slight sore throat that is worse in the morning and gets better throughout the day, very slight itching in my ears (this doesn't happen often), and post-nasal drip.  I figured this was allergies, but could this have anything to do with the tooth pain?
Thank you for your time,

Hi Lauren,
Sorry to hear about your recent dental pain.  After fillings, it's normal for teeth to be hypersensitive to hot/cold for a couple of weeks after the filling is placed; though this is more common with the white, composite fillings.  Also, this hypersenstivity shouldn't last 20 minutes.  This type of lingering pain is more often associated with a tooth that needs a root canal.  

All the nerves in the head and neck are very closely related, which makes it very difficult to localize the dental pain to a particular tooth without specific tests for individual teeth.  Referred pain is common and makes diagnosis tougher and can make you think and feel that the pain is coming from a particular tooth, when it's really from somewhere else.

I would consult an endodontist to evaluate your pain and localize it to the exact tooth/teeth involved.  You can ask your general dentist to refer you to an endodontist because you would like a specialist's opinion and evaluation.  Or you can use the (or the phone book) to find an endododontist and learn more about root canals.

With regard to your sore throat and post nasal drip--it sounds more like allergies.  However, if you have any facial swelling, you should contact a dentist as soon as possible.

Best of Luck,
Ketan Amin, DMD
Austin Center for Endodontics (Root Canal Specialists)
Austin Center for Endodontics


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Ketan Amin, DMD


Graduating from Harvard School of Dental Medicine, I received a broad understanding of both medicine and dentistry. I continued my training at New York University, as a dental specialist in endodontics, which concerns root canal therapy, related surgeries, as well as diagnosing and managing various forms of pain occurring in the head and neck


Dentistry; Specialist in Endodontics (Root Canal Therapy).

American Association of Endodontics American Dental Association American Academy of OroFacial Pain

Harvard School of Dental Medicine-Doctorate in Dental Medicine (DMD) New York University College of Dentistry-Certificate, Endodontics

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