You can find the bulletin here: http://umanitoba.ca/admissions/media/dentistry_bulletin.pdf. It lists the minimum DAT score and core course GPA needed for an interview invite. It changes a bit every few years.
Interview invites are based on core course GPA and DAT score (regular applicants). AGPA is looked at only for the final decision. On average I would say accepted applicants usually have an AGPA of about 4.00 or higher.
Hope that helps. Good luck!