Charles Stent Charles Stent Charles Stent (1807–1885) was a 19th-century English dentist notable for his advances in the field of denture making. In 1847, Edwin Truman introduced gutta-percha as a material for making dental impressions; however, this was unsatisfactory for several reasons, including its tendency to distort upon removal from the patient's mouth, and to shrink upon cooling. In 1856, Stent added several other materials to the gutta-percha, notably stearine, which markedly improved the plasticity of the material as well as its stability. He also added talc as an inert filler to give more body to the material, and red colouring. The
Charles A. Hufnagel Charles A. Hufnagel Charles A. Hufnagel, M.D. (August 15, 1916 – May 31, 1989) was an American surgeon who in the early 1950s invented the first artificial heart valve. Dr. Hufnagel was born in Louisville, Kentucky and was reared in Richmond, Indiana. His father was also a surgeon. He graduated from the University of Notre Dame and earned his medical degree from Harvard Medical School. At Peter Bent Brigham Hospital, he began work on the heart and other organ transplants and explored the use of plastic to replace blood vessels, developing a technique called multi-point fixation, which would have great