I'm from ucla 2003. After the first year, only two out of 85 dropped out from my class. One went to ucsf med school and the other one had the career change. I believe that most of those students who dropped out of the program had problems with their committment on becoming a dentist. If you have the passion, you'll be fine. Just stay focus and have fun in school. You'll be fine. Congrats for your acceptance to the dental school. best of luck.