At michigan we have the following schedule our first semester.
M: 8 or 9 am - 4pm
T: 8 or 9 am -5
W: 8 or 9 - 4
Th 8 or 9-5
F: 8or 9-5
Classes we take are: Clinical foundation, Dental Anatomy, Behavioral science, Intro to Profession, Developmental Biology of Dentition, Biomaterials and IMS (this class replaces all of the Immuno, Histo, pharmaco, biochem, gross etc. all the science classes and it runs thorught 4 semesters and it is our biggest class, 8.5 credits)
It may seem like a crazy schedule but it is while you are in school and rest is up to you and how you study and time manage. Most days I don't study from 5-8pm, usually take a nap, workout or something else and study about an hour to two a day. Mostly I study couple of days before the exam and rest of the time night before the exam depending on how big the exam is and I rarely study much for the quizzes we have. I usually get bout 8-9 hours of sleep everyday and about 10 hours on weekends. I have been able to go out and get beers on every friday night. Also, I have yet to study or do anything productive on saturdays, college football(we are No. 2 right now) takes all the time, what can I say. I usually try to catch up on sunday by studying about 10 hours and that's about it and mostly find time for anything I like to do. Dental school is definitely time consuming but lot easier than undergrad engineering classes I took. Also, I try to do my best in classes but I don't want to specialize so I don't kill myself over few points I miss in an exam. It is definitely doable. I know this is just first semester and I might need to study more in upcoming semester but I don't think you really have to do 24/7 like some people on this board make it sound like. I was prepared for worse but overall I really do enjoy dental school.