UoP is a competitive school. I bet if you are good enough to get in there, then you are good enough to A's in your last two semesters, but they let you get B's to give you some breathing room.
Anyway if you can't keep a B average in a college semester then dental school will be a real wake-up call for you. My first semester of dental school contained 27.5 credit hours including Biochemistry, Physiology, Embryology, Neuroanatomy, and several dental classes too. Those making below a 3.0 were in the bottom quarter of the class.