In general, do not expect to receive any financial aid from a school other than government loans. Dental school is different than undergrad, there is simply no "free" money. Very few people can afford dental school and they either take out loans or get a military scholarship. It's just the way it is.
There are a few limited occasions where schools will award merit based scholarships. From what I've seen, these are not very common and a lot of them are only one year awards of a small amount (I saw this at Tufts and NYU, for instance). Of course there are schools that offer large partial or full scholarships (Penn is one, I think). There is really nothing you can do to apply for these scholarships though. Everyone is considered and the school will let you know when you're accepted if you were given an award.