I am getting a BS in Biology and a BA in Chemistry and it will make you stand out when you apply. I have found that it doesn't take to much more effort than just a minor in Chemistry, except for a few more classes like Physical Chemistry, Biochemistry (which is a suggested pre-dental course anyway, and also counted towards my biology degree), Biological Chemistry, and a two credit research project (which also looks good for dental school). I know an oral surgeon who did this, he is the one who suggested it to me, and he said it put him way ahead of the game when he got into dental school. So it is definitely worth considering, but talk to an advisor for your school because I am sure the curriculum for you will be different. One thing of caution however, a lot of these courses are hard, especially when you are taking them with upper level biology classes and other stuff, so it isn't worth it if you get bad grades in all your classes. So make sure it is something you think you can handle, and it may take you an extra year to graduate like it will for me. While the schools will give you a nod for the tough course load, if it is all C's then they will still see that GPA and it won't look good. So these are other factors to consider. Good luck!