Boy, I don't envy you at all. Toothaches are just MISERABLE!! I only had a real toothache once - when I was in elementary school & cracked a tooth, but I just remember it being hell. My mother has gone through a lot of tooth problems lately, & she every time she has been in so much pain, that just passing air over her teeth sends her jolts of horrible pain! I do hope that they can finish your tooth work soon & that you will start feeling better!
I know that you have mentioned your issues with the fentanyl patches before -- have you spoken with your doctor about this yet, or at least getting some kind of break through med? I'm on fentanyl patches as well, but sadly, I couldn't tell you how long they last for me, as they provide no relief at all. I'm at 150 mcg/hr currently, and if I didn't know I was wearing the patches, I wouldn't know that I was wearing anything (but that's the way I am with all pain meds, it seems). I hope your doc listens to you & adjusts your patches accordingly.