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
Laser surgery The laser surgery for dermatology often bypass the skin surface. The principle of laser surgery for dermatologic problem is based on SPTL (selective photothermolysis). The laser beam penetrates the skin until it encounters chromophore which absorbs the laser beam. After absorption of the laser beam, heat is generated to induce coagulation, necrosis of the targeted tissue, this results in removal of unwanted tissue by laser surgery. Laser resurfacing is a technique in which covalent bonds of a material are dissolved by a laser, a technique invented by aesthetic plastic surgeon Thomas L. Roberts, III using CO lasers in the 1990s.