Manhattan is a very safe city (for the person who asked above).
I walk home from the library sometimes at 2am and am never scared. I know nothing will happen because there are people outside at all hours.
If you are super paranoid (which you shouldn't be) you can hail a cab in 1 second. There's no way you can get lost in Manhattan because it is super easy to get around. It is the easiest city to get around in (IMO).
As far as the area, where the school is, it's near all the hospitals. It's on first avenue which isn't all that glamerous. There is some goverment housing, etc. so it's not the nicest area (def. not as nice as where the undergrad campus is), but it's still safe.
If you walk a few blocks away though, it is a good area with lots of restraunts, etc.
As for students being kicked out---if you get kicked out, you deserve it.
You really have to NOT STUDY in order to get kicked out. I have seen people never attend a single lecture, study two- three days before an exam and still manage to pass. How many times is someone going to have to say this????

If you study and go to class, you'll pass...if you never go to class and cram for two-three days, you'll pass. If you get kicked out, you don't deserve to be a dentist.