I always get nitrous oxide if I'm getting a cavity or anything that would lead to a needle at the dentist. It's more money but in my opinion worth it. I think you already had your appointment so I hope it went ok. You can always tell the dentist "I did to become very anxious at the dentist and would it be ok to take my xanax before this procedure" If they say no ask them for a suggestion - my dentist is amazing to work with that way