Pain and sensitivity after permanent tooth crown

I had a permanent crown put on the second to last molar on the bottom left about four weeks ago. It was to fix a filling that had cracked and fallen apart. For the first couple of weeks after getting the crown, it was sensitive to chew on, but not painful. However, over the last week or so it has become very sensitive to hot and cold. It is even sensitive to things that aren't that cold, like pasta salad. It is also still sensitive to chew on, and there is a consistent dull ache from the tooth pretty much all the time. The gum around the area looks fine and is not inflamed or anything.

Any suggestions on what this may be from? Will it go away on its own? I'm dreading the idea of a root canal, as I've heard nothing but horror stories about getting them while the nerve is still alive and working.

[scottma]

If your restorative dentist can not solve your problem, seeing an endodontist and/or prosthodontist is advised.