1. Departments of Biologic and Materials Sciences University of Michigan School of Dentistry 1210 Eisenhower Place Ann Arbor Michigan 48108
2. Facility for Electron Microscopy Research Department of Anatomy and Cell Biology and Faculty of Dentistry McGill University Montreal Quebec H3A 2B2 Canada
3. Office of Research College of Dentistry Ohio State University 4139 Postle Hall, 305 W. 12th Ave. Columbus Ohio 43210