Yes, do have that cavity filled immediately before you get your braces on. If the filling needs to be on the side of the tooth, it will most definitely need to be in place before the bracket is glued on. You may be getting just your top braces first, and if the cavity is on the bottom, you may have a few more weeks to get it filled. Call your ortho and ask them about it if you have any doubts...but I would go ahead and make a dental appointment.
As for what to expect...I just got my braces on last week so feel free to ask me anything. This whole process is pretty new to me and it's been quite an experience, though a really good one!
I went in that morning, scared to death, lol. I had nearly chickened out and cancelled my appointment! I knew in advance that I would be getting the clear ceramic self-ligating brackets by GAC called InOvation C. I also knew that I was only getting the top ones that day. Well...the whole process took like 20 minutes max. A technician put a thing in my mouth to hold it open and hold my lips back. I looked pretty funny I'm sure but it wasn't uncomfortable or anything. She told me exactly what she was doing and got the brackets ready for the doc and brushed an etching material on the fronts of my teeth to help the glue bond. It smelled kind of like nail polish. lol Then, starting with a back molar, he glued all of the brackets on and, after each bracket, held this tiny light over them to set the bonding glue. As soon as he was done the thing to hold my mouth open was taken out and I had to rinse my mouth...it felt SO weird with just brackets and no wire. REALLY WEIRD! He then removed any excess glue/etching from around the brackets so that my teeth didn't feel rough. Then, in like 2 seconds, the technician put the arch wire in and closed each bracket over the wire. Then I got instruction on brushing, flossing, etc. It was a really fast process and not a big deal.
The ENTIRE rest of the day I kept smiling in the mirror, examining them, showing them off, etc. It was pretty funny. Not to mention, I kept moving my lips and tongue over them because they felt so strange. Be careful doing this though because it can rub your mouth raw...and gob the dental wax they give you on them if they start to rub your mouth the least little bit. Anyway, that was around 5 days ago for me...now I'm about used to them. At first my teeth felt slightly pulled and I could feel the pressure. That is gone now, they don't hurt, and I'm pretty used to them. I can already tell that a couple of teeth have moved. Yay!
Good luck with everything! If you have more questions, just ask
![Smile :-)](./images/smilies/icon_smile.gif)