It is important to meet the requirements for all of the schools that you will be applying to.
If you have that down, great! If you are unsure then, rather than go to each school's website to figure it out, get a copy of the "ADEA Official Guide to Dental Schools." It has all the stats that you need to know, in a concise and easy format.
Beyond meeting the requirements, additional courses in the following may help you when you get there: Anatomy, Physiology, Biochemistry, Histology, Microbiology, Immunology, Virology, Business, and anything with hands on application (art, including: sculpture, mechanics [such as car repair, assembling furniture, or learning to play an instrument], etc.). They show admissions your likelihood to survive the curriculum, pass boards, etc. No one, as I've seen in other posts, is "out to get you." They really don't have time for that.
Additionally, no matter which school you get in to, you'll be challenged in these courses. The more familiarity you have in each subject, the more flexibility that you will have to slack a bit in one to focus on another, in order to maintain high academic standing. Most importantly, you'll be best prepared to utilize the time of the professionals there, out of there good spirit, to train you to become the best you can be in order to treat your patients and not simply their disease.
Back to your final question. To get an interview requires that your application stands out. Grades and GPA are important, and must meet some minimums that are different for each school (higher the better), but they aren't the only factor. First, I suggest that you create an AADSAS (if you haven't already) and go through it to determine where you are strong and weak and get some experiences to add for a balance. Secondly, get a reliable person or two, that are grammar masters with real world experience, to help you with all final drafts of your AADSAS writings. Thirdly, if you are still searching for recommendation writers, ask if they would be willing to write you a "GOOD" letter, giving them a minimum of 2-4 weeks notices, and follow up with them to submission. Finally, submit your AADSAS as early as possible because all the schools (that I researched) are on rolling admissions. If you don't know what that is then Google it and PM me if it still doesn't make sense.
I'm sure this won't answer all of your questions but I hope that it helps.
Mike
