Also during the 1500s, Benvenuto Cellini invented gold casting, which later became the basis of casting gold inlays, and Jacques Guillermeau advocated the use of wax, coral, and mastic for artificial teeth rather than ivory, which is porous and becomes discolored in the mouth. Ambrose Paré, the French surgeon, devised methods of extraction, recommended gum incisions for difficult cases of tooth eruption, and suggested the use of artificial teeth made of bone. However, he and others still believed dental decay to be caused by worms.
In France, the term chirurgien dentiste came into use around 1620, and by 1697 the practice of dentistry was regulated by the government of that century. Anyone who wished to practice dentistry in France after that date had to enroll in the College of Surgeons, work for two years with a licensed dentist, pass an examination on the theory and practice of dentistry, and take an oath before the chief surgeon. Licensed dentists, however, generally limited their practice to the wealthy, and most of the common people were treated by barber surgeons, tooth-drawers, and itinerant charlatans.