If you look at the copy of your AADSAS confirmation sheet it states the school code on the upper right hand side. Some schools will pretend to not know and ask you, "how many schools are you applying to?"
If you are applying to 20+ then be prepared to answer why. Other questions might ask: Where have you gotten interviews so far?"
Even though these questions really don't determine your passion or motivation to pursue dentistry, they might help schools figure out if you really want to go to their school or just want anything that will accept you.