I've heard from a few people that UCSF allows people to live a life while their in D-school and students don't have a hard time there. They want people to balance their lives and not stress too much, people don't really fail. But then again UCSF is really hard to get into and the people there must be really smart.
I wouldn't worry about easy/hard dental schools though. So many people have said that once you're in, you will be a dentist. If you put in the time and the work that you need, you can feel pretty safely assured that you will make it through. There is a lot of support for the students. Once you are in, everyone there just wants you to make it. They don't try to challenge you and make your cry like some undergrad profs...but you just try your best once you're there and those who really want it, make it.
At Buffalo, they told me they have a big brother/big sister program so older students help you out. The faculty is almost at a 1:1 ratio with the students so they are very helpful and caring. Dr. Brown (the dean of admissions) always has his door open if you need help and advice...all the profs have an open door policy. There is even someone you can see for therapy if you are stressing out too much. It's pretty tough to fail, they are more likely to let you do a year over than kick you out at Buffalo.
..NYU however, I hear kicks out the bottom 20 people.
Anyway, just try your best. Cheers.