I've been to a few dental school interviews so far, and they're not bad at all. Like others have said, the interviews feel more like conversations than job interviews. As long as you have confidence in yourself and know why you want to pursue a career in dentistry, you'll be fine. You've made it this far in the application process, and in my opinion, the interview is the easiest part.
I'll be at NYU for an interview on Friday, too. Maybe I'll see you there!