Karl F. Leinfelder, DDS, MS, is Professor Emeritus at the University of Alabama and an adjunct professor at the University of North Carolina. He also maintains a dental consulting company, and he is a primary consultant to major dental materials companies nationally and internationally. A graduate of the Marquette University School of Dentistry, he has published more than 200 papers on restorative materials, contributed to three textbooks, and lectured extensively nationally and internationally. Dr. Leinfelder received the Academy of Operative Dentistry's George Hollenbeck award for outstanding research contributions and the American Dental Association's Norton M. Ross award for excellence in clinical research.