I have interviewed at both, I think that it is equally hard at both. Case will have a record number of applicants this year and AZ has all new facilities (its a new school).
(FYI over 16,000 applications on sept 1 from AADSAS)
In the past Case has been known for accepting anyone; hence the term, "I am applying there just in Case". I honestly feel like times have changed.
Case starts early and that helps them to steal a ton of great students. Everyone thinks it is an easier school to get accepted to, so they have over 3500 applications this year. Many people will be disappointed to think that an 18 or a 19 won't get them in to Case, and anything (22,25,etc ) won't get them in this late.
Az is a whole different ballgame as far as dental schools go. Most people have a negative attitude about it because of the wacky interview technique they employ. It makes it seem harder to get in then it really is.
Case fills their class all at once where AZ offers only half of its total seats in Dec. So a late applicant with a decent DAT score has a chance, where you would be at the bottom of the alternate list at Case and interview in March or April.
They are different, but I would say my chances to get acepted into either school are pretty equal given the fact that I applied early and have decent stats. 😍