Thanks for writing janamcd, but sorry to hear that you are having these difficulties. My wife, Kelly Mack (a contributor here), has had RA most of her life and as a result has a smaller than average mouth and an inability to open wide for the dentist. In our experience it has helped to look for a dentist with some experience with such cases (do they understand the need for frequent breaks) and also has the smaller devices for x-rays (they can be particularly difficult). Kelly also pre-medicates to help deal with any pain, but you should check with your doctor about something like that.
Hopefully others can help with tips from their experiences. Wishing you the best and keep us posted on how you are doing. Richard (RheumatoidArthritis.net Team)