It's all about phrasing
1) Columbia University Dental Conference: Toured Columbia sim. lab, clinics, and got hands-on activity with some of the Dental Students.
Might alienate potential schools, so lets switch it up a lil. Look at your conference and see whether they go under different aliases that will not alienate yourself.
2) New York/South New York/ NY Dental Conference 2011: Immersed in sim. lab techniques, future clinical studies, and had hand-ons activity with various Dental Students.
Now you can list it under your EC's. Another example: 1) UCSF Dental Conference...No. 2) City of S.F. Dental Conference.