No matter how hard someone studies, there is a cap to how well they'll do academically - dumb people will likely never achieve a high GPA, but they CAN log a lot of hours in a clinic and learn more useful, dental-related things.
If i was an adcom, i wouldn't care if you can recite the full oxidation of para, para' 2, 3, 7, 8 dichlorodibenzotrichloroethane..but if you could show me the proper technique of putting on a dental dam; how to trace a cephalogramic x-ray; or tell me what to look for in a panorex..that's impressive.