Everyone has given really good answers and I can agree with what they all recommend. I would advise taking Biology as it will help with your studies but its important to look at what the college/university require from their students ( try searching online the course pages at different institutions).
My alma mater, NYU College of Dentistry, clearly states the requirements for entry on its website. I would bet that most other schools do as well, and that the requirements are very similar:
I definitely agree with Steven's answer and want to point out that there's no necessary major for dental school as long as you fulfill the requirements. Your undergraduate experience is really a time for you to choose which classes you might have an interest in outside of science/biology and there's no set rule that you must major in a science related field. I highly recommend taking advantage of all the electives that might sound interesting to you in college before going to dental school because that's really your time to learn what you want! Good luck!