Did you have a root canal or just a filing?
I had a root canal and I swear for years I kept saying that that area was bugging me. everyone kept saying "you had a root canal, you should not be able to feel anything." so I chucked it up to anxiety and finally moved on.
Years later, a new dentist did some xrays of my teeth for my yearly exam and said he saw a shadow at the tip end of the nerve of the tooth. it was faint, but there. He sent me to an oral surgeon to check it out. The oral surgeon said I have very long roots on my teeth and frequently folks with long roots dont get the full benefit of a root canal because the instruments they use dont always reach the bottom of the canal, and they usually leave some infection behind. Then it takes years for the infection to rear up again.
He gave me two choices. I could pull the tooth (which I am against) or I could have the root of the tooth sawed off. That would be a surgical procedure done in the office. I chose that one. I was given a truck load of novacaine, and it only took a few minutes. He said that a pocket of infection had broken thru the floor of my sinus and was hiding there.
Once the procedure was over, my weirdo pain went away.
I would suggest having your dentist really look at the xray the next time you are due for an exam, and closely examine the area you are sensitive about. TN is normally VERY painful, and you dont normally question it, you need strong pain meds to get thru it.
I hope you feel better.