Make sure that your dentist and the other staff know how anxious you are. I would ring them before and tell them that you can't hang aound for ages.
I would also ask before if he or she can suggest something they may prescribe a small amount of something like tamazpan.
i am with you I have had so much treatment due to one of the conditions that i have although I have to say that it was the dentist that diagnosed it.
Good luck with it.

__________________
Kiss
God laughs at people who make plans.