Hi Flora
I have had sedation several times at the dentist (big phobia...) and it was great for me, reduced my anxiety beforehand because I knew I wasn't going to be aware of anything, and helped me sleep through the worst of the waking pain when I got home because of being zonked out lol

You definitely need someone to drive you and be there for the rest of the day - I was always very smiley and a bit drunk coming out of it!
I've talked to my dentist about the CRPS and we have an action plan should I need any major work. He will try to see me as quickly as possible so that I am not in pain for too long, and will sedate me. He will use the other local anasthetic (not the normal lidocaine one, which I've read isn't as good for us) and use double amounts to really numb the area. After the treatment is complete he will again use the local to numb everything, so that everything in my mouth has a chance to settle down a bit before feeling comes back.
From everything I've read about dental work and CRPS (I've read a lot because of being so scared of it anyway...

) the two most important things are to reduce anxiety and stress and pain before any work, and to delay any pain afterwards for as long as possible, and then really control it. Better to overdo the caution side IMHO.
I wish you loads of luck. Anything like this is fairly scary, but it can be managed if you have a compassionate and understanding dentist. I think there's a page on this on the RSDhope website that you can print and take to them to discuss it through.
Bram.