Dr. DiCostanzo earned his DDS degree from Loyola University. Since that time, he has practiced dentistry in the Hammond/Munster, Northwest Indiana area and in Oak Brook, Illinois. Dr. D has taught dental classes at Loyola University and currently operates the Dental Assistant Training School.

His memberships include the Academy of General Dentistry; the Indiana Dental Society; the Illinois Dental Society; the Chicago Dental Society; the American Academy of Cosmetic Dentistry; the Academy of Sports Dentistry; and the Northwest Indiana Implant Study Group.