About 50 academic staff attended the ceremony.
Dental faculty dean Prof Paul Brunton said the new building, due to be completed by mid-2018, would further improve the quality of dental students.
''We are aiming to be in the top 10 [dental] schools by 2025.''
A university spokeswoman said contractor Leighs Cockram JV, a joint company made up of Leigh's Construction, of Christchurch, and Australian company Cockram's Construction, would begin construction of the $125 million facility within the next week.