Questions were pretty typical -- why dentistry, why ECU, why you. Check interview feedback for more detail, but I didn't get any that surprised me or caught me off guard. They know your app REALLY well and interviews are open file, so all of my interviewers spent a lot of the interview asking me specific questions about my experiences. That really impressed me.
You start off with a little Q&A, introductions, etc. Then you're put into 2 groups and one group does the group learning activity while the other interviews, then they switch. Everyone in my group thought the group learning activity was really fun and interesting, so don't stress about it. Then you eat lunch with some dental students. After that's the financial aid presentation and the tour. You'll be in the new building all day and the facilities are really incredible. When I was there we were able to tour all of the clinics and labs and poke around a little bit, which was great.
The whole day was really laid back. They definitely want you to relax so they can see who you really are and what you're really like. Be yourself! As Dr. Wilson will tell you, they have good BS detectors.
Good luck!