During the course of this year, 1990, dentistry will celebrate its sesquicentennial as a profession. In February 1840, the Baltimore College of Dental Surgery, the Dental School of the University of Maryland, was chartered by the Maryland General Assembly as the world's first dental school. In the same year the American Society of Dental Surgeons, the antecedent of the present day American Dental Association, was founded, also in Baltimore. In the previous year, 1839, the American Journal of Dental Science was initiated as the first periodic scientific and professional publication in dentistry, later evolving to the Journal of the American Dental Association. With the congruence of three fundamental elements which are essential to any profession--a unique program of education, a formal means to communicate and freely share new information, and an organization devoted to maintenance of professional ethics and standards through self-regulation--dentistry began evolving to its current status as a valued and respected health profession. From its birth and through the intervening century and a half, dentistry has been a profession heavily reliant on technology as well as science. Dentists variously are credited with the discovery and development of general anesthesia and the precision casting technique; and they make significant use of rotary cutting instruments, ultrasonics, laser technology, unique biomaterials, and intraosseous implants, to mention only a few techniques.