I found Docere.com -Dentaltown via some link somewhere in SDN and found it to be very thought provoking. Dentaltown is a site used by practicing dentists, etc., and there are some good threads up about how to choose a dental school. The consensus being that you'll become a dentist now matter where you go and you should avoid as much debt as possible (i.e. go to the cheapest school). It's kind of hard advice to swallow for those like myself who dream of going to more expensive schools such as Penn, NYC, etc., but a good thing to think about. Everyone should sit down and estimate how much debt they will have after dental school, how much interest they will have to pay over the life of their loan, and how much that money could be making if invested instead of spend on dental school. Money isn't everything, but doing this allows you to ask yourself if wonderful private school X is worth 300-400K for four years when you might also have to think about a house, family, establishing a practice, and (most importantly) taxes when you finish.
It's tough, and I still don't know if I'll be able to turn down Penn, if accepted, for my state school IU (also if accepted). Money is the only real, quantifiable thing we are dealing with in this descision, though. That's why I feel it is important to put a monetary value, even if arbitrary, on all of the things you consider when choosing a dental school.