Hi A.. I do understand how scary this can be. When my son was a couple months old, we had to take him in for an exploratory surgery. I don't remeber a whole lot as it was almost 3 years ago, but I do remeber that the "before" was worse than the "after". I couldnt feed him for 12 hours before the surgery, and with a 2 month old baby,....it's painful. I knew he was hungry, and I couldnt feed him. When I had to hand him over to the anesthesiologist, I cried and cried. It wasnt for fear of what they would find, it was because they "took" my baby, and I couldnt be in there to make sure he was okay. The surgery went well. No complications, but when he came out he was groggy. I'm sure there were things they told me to watch for after the surgery, but I don't remeber what they were as he didn't have any trouble. Being older than my son was, she may be a little disoriented. Perhaps you can take her favorite blankie or dolly or stuffed animal for comfort. Don't let her see you concerned as she will pick up on that and think there is something wrong. We sorta made a special day of it and even wore a special outfit. Let her know that its a "happy" day 'cause the dentist is gonna make her teeth all better. I suspect they are not letting her eat for several hours before the surgey/procedure, and i'm not sure exactly what the procedure will entail, but if its alright and not painful for her to eat, maybe you can pick up a special meal that she likes. If you can, try to make it a day of snuggling, and cuddling and just take it easy....both of you. I hope some of this helps! I'll say a little prayer for everything to go smoothly tomorrow.
I also wanted to add that juice is okay, in moderation. It's good that she only gets it when shes in her chair, but I would suggest that if she does have juice during the day, brush her little teeth before you get her out of her chair. My oldest son, when given the choice between juice and water, will almost always choose water because he knows its better for him and I let him know that he made a really good choice. He, of course, wasnt born that way...but I've worked with him on it. My younger son however, REALLY likes juice. IF he gets juice, its about 3/4 water. I chose to take the lazy route and just stopped keeping it in the house. That way I don't have to battle with him each time and I can just tell him we don't have any. Whatever you choose to do, good luck. It can be tough. :)