If you like it, then do it. I was a non-science major, and my major classes were a nice break from all the sciences. I love science, but I didn't want to do that 24/7 when I'll get enough of that in dental school. I wanted to take the chance to learn other things in undergrad. And I think being well-rounded will only help. Most people I know who are bio majors did it because it overlapped with their pre-health classes, so they didn't have to worry about other requirements. Doing pre-health and non-science major is basically like double-majoring, but it's not overbearing or anything. You learn new, different material, you can offer some diversity to your dental school, and so on. And while my non-science classes normally wouldn't be easy A's, they were a joke compared to my sciences. I'm sure dental schools will expect that, so you still have to have a solid science GPA.