Dentistry is practical.
The system has let you down. Somebody dropped the ball. Big-time. Somehow; you were allowed to enter a degree which leads to an almost purely practical vocation with no entrance criteria testing your abilities in this area. Your intellect got you in the door of dental school; but the truth is that only finely tuned practical skills will get you through successfully. To remove decay, perform minute fillings and safely control a 500 000 rpm dental hand-piece you must achieve a high level of dexterity.