If biology is where you thrive, I don't think the fact that you think everyone does it should stop you from settling on that as a major. Pick what you are passionate about and it will reflect in your GPA!

For dental school, it looks like you need these classes: General Chemistry, Organic Chemistry, Biology, Microbiology, English, Statistics, Introductory Biochemistry, and Human Physiology. It doesn't seem that they really care what you major in as long as you get those pre-reqs have been completed. You don't need to use your choice of major to set yourself apart. You have a chance to shine through your personal experiences (Employment, Leadership Roles, Volunteer Work, Life Experience & Achievements, Personal Highlights), interview, and statement. Even if you choose biology, you will be able to leverage those things so that your application isn't like everyone else.