The basic truth of any interview is that they are used simply to assess your ability to talk and whether or not you demonstrate a genuine knowledge and motivation to be a dentist. Questions will arise, but they are not usually in the form of a Q&A type of interrogation, but rather come about during the course of the conversation. Thus in answering your questions, my opinion is that you have some power over what interview questions are asked of you, by how you shift and carry your conversation, and what you yourself want to focus on talking about. That has been my experience; no interview has been stressful yet.