Dentistry to me seems like a more "noble" pursuit, if you will. Business (in my opinion) is like selling your soul to money. Also, in business, you lack a physical skill that you can market. Sure, you're good at talking to people and selling stuff; but it's not the same as a dentist who has an actual skill they've trained for and been licensed in. Also, dentists have more opportunity to actually help others in an obvious way. You can always combine the two as well..... I'm sure some dentists played roles in establishing large dental practices like Aspen and Gentle Dentist, and they're probably doing very well for themselves.
What is drawing you to each field? What is making you wary of each field?