One. You can only go to one dental school. The interview is the last step in the admissions process. Your application got you there. You fall into the admissions criteria for acceptance. It is now yours to lose. Prepare the same way you would for an oral exam. Walking in cold is IMHO a crapshoot. One of my former residents answered one of our no right answer interview questions this way:
Given the choice, would you prefer to be skillful or lucky?
Answer: Lucky. Luck comes to the most prepared.
Still the best answer to that question we have heard. Thanks Erica.
Prepare for the questions you know you will hear, so that you do not fumble for an answer. Read up on interview protocols and strategies. There is plenty of good info out there in books and on the internet.