Tooth pain, root canal, and CRPS

Hello,
I went to a dentist yesterday because of severe pain and the dentist said that I need a root canal--based on the severity and persistence of my pain and x-ray. Xray showed a dark area NEAR the pulp, but not touching. Looked like the enamel area to me. A premolar bottom right.

I did have severe pain, which has somewhat subsided and changed. Before the severe pain, I had a very sensitive tooth. The dentin is exposed near the gumline. But, this is not the same tooth that the dentist says needs to be removed. Though both have exposed dentin. When the pain became severe I took hydrocodone every 4.5 hrs or it hurt terribly over much of the one side of jaw and mostly on the bottom. Today I took only half a pill this morning because I couldn’t stand the pain with eating. Before eating the pain was fairly mild. Now, the pain is NOT terrible and it is just as bad in other locations on the same side of my mouth.

The typical question: Do I really need a root canal? I am particularly concerned about this because I have had CRPS in the jaw and face before, and I wish to be sure that I actually need a root canal and that the severity and spread of my pain is not just caused by my nervous system and possible a CRPS type reaction.

Knowing that my first question is: HOW CAN I BE CERTAIN THAT I ACTUALLY NEED A ROOT CANAL? Under my circumstances, I would be more comfortable with a diagnosis that was NOT DEPENDENT ON MY PAIN SYMPTOMS. (I would actually like to try using Lyrica, which is what cured me or CRPS before, but my dentist would not prescribe it. The time I used this medicine before, I only needed a low dose and was cured in about a week. FYI—I was misdiagnosed with TMJ disc being out of place, had an unnecessary procedure that made it worse. I couldn’t open my mouth and had pain over much of one side of face. And, this was all caused by getting a cavity filled—the dentist was quite rough with my small mouth.)

2nd question later--doesn’t fit.
thanks

[scottma]

Seeing an endodontist is advised.