People change majors all the time. Not every applicant has a science degree when they graduate. As long as you have your pre-reqs done, they probably won't care. Did you indicate on your application that you will be getting a biology degree? Are you even applying this year? If not, don't worry about it.
The main thing to consider right now is if you hate bio classes now, how will you manage to survive dental school? Maybe you should take a few upper level courses now and learn to adjust to the difficulty rather than jump into the thick of it once you're in dental school.