To add to this, I absolutely agree that you should get your dental work done now. In fact, the dental forms literally say that you can not turn them in or have the dentist sign them until AFTER all work is complete. So if you need cavities filled, root canals, or any other fun stuff, do it now!
As for the other stuff, you will need some pretty standard testing done if you are invited. This includes TB tests, G6PD test, HIV test, and basically a full blood workup. There is a time limit on most of this, which I believe is a year or so, so if you can get those things done now you won't have to do it again later assuming you are within the timeframe. I don't have the forms in front of me, but I'm sure that somewhere they are posted on line that shows everything you need and how long they are good for.