Hey shaby,
Firstly, congrats on having a couple of interviews lined up - that's something to be proud of.
I've only been on one interview so far, but it seems like the majority of questions that were asked centered on ensuring a couple of central themes:
1) you could put together a coherent sentence without stumbling all over yourself
2) why you chose pediatric dentistry
3) how the program you're interviewing fits with what you're hoping to accomplish or get out of residency
I had a couple of other random questions about a difficult situation/case/patient, previous research or clinic experience, and long term goals. You should always be ready for the 'tell me about yourself' question as well.
Pretty basic stuff, so try not be nervous (much easier said than done). And while it may be common sense, it's worth repeating that anything related to the process including dinner the night before or lunch with residents during the day off is going to be part of the evaluation.
It's a tough process, and while it sometimes feels like I'm just trying to match into any position, it's important to find out if a program is going to be a good fit for you on your visit as well. 2-3 years may not seem like a long time, but if you don't see yourself meshing well with the faculty, staff, or fellow people you're interviewing with, then I wouldn't rank that program very high (but at least rank it).
Hope this helps someone out there - cheers!