Gold has found great application in Medicine and Dentistry, which evolved in two directions. First, as a built-in element in the human body, which has been made possible by the development of numerous gold alloys. Over time, due to their favourable properties, gold alloys have found wide application as diverse embedding elements in Dentistry. Furthermore, the flourishing of Nanotechnology created the conditions for the mass production of gold nanoparticles of various qualities with versatile applications in Medicine and Dentistry, as well as cosmetics and food. The appearances of gold nanoparticles in various applications and situations are roughly shown in second part of the introduction.