if you are practicing dentistry for the government, as long as you are licensed in ANY state, you are good to go. it doesnt matter which board you take as long as you are granted a license by a state. if you want to moonlight, you will obviously have to be licensed in the state you are in, but states have no licensing jurisdiction on federal property. as a side note, something i learned at the clinic this week...you dont ever HAVE to have a license to practice in the military. apparently, some folks are out there as dental officers, just not getting their special pays and bonuses. i havent met any myself, so it might be a sea story, but there you are...
if you are not in florida, i would suggest you avoid the florida boards. they can be a serious pain, according to several of my classmates that looked into practicing in florida.