Q. I have severe pain after a deep cavity filling. What is wrong?

Hello doctor,

I had a deep cavity filled about five weeks ago. I had extreme sensitivity to cold since it was filled. I had no other pain associated with the tooth. Biting down was completely fine. Two nights ago, I started to get extreme pain on the right side of my face and jaw (the same side the cavity was filled). It was keeping me up all night. The next morning, the cold sensitivity was completely gone, but the extreme pain on the right side of my face and jaw would come and go. Later in the day, I flossed, and the tooth associated with the cavity started bleeding. Now, it hurts extremely bad to bite down on that tooth (where the filling took place and where I flossed). The throbbing pain on the right side of my face is occurring more frequently but still, comes and goes. I have a root canal scheduled for next week on that tooth, but is that what is wrong? Why did the pain change from cold sensitivity to this completely different type of pain over night? I do not think I can deal with this pain for another week. Any help would be greatly appreciated.