Before artificial (porcelain) teeth came into use the following substitutes were employed, their estimated value being in accordance with the order in which I name them: Human{334} teeth, animal teeth, hippopotamus tusk and teeth, elephant-ivory, and bone. _Human Teeth_.--Transplantation of teeth was at one time very common. After being inserted, they were held in place by pivots and ligatures, springs, and upon bases. The pivot method also included the use of screws. Ligatures for fastening teeth were made of silk-worm gut,--which, now so common in surgery, was used for this purpose, perhaps, two hundred years ago,--of gold wire, etc. The method by ligatures is the earliest of all. Human teeth have always been more or less expensive if fresh, few people being willing to part with sound teeth except for a money consideration. In 1784 a Philadelphia dentist offered, in an advertisement, two guineas each for sound front teeth. _Animal Teeth_.--These were largely used, being held in place the same way as above, the principal objection being that it was difficult, often impossible, to match human with animal teeth. It was found, also, that the latter decayed very much more easily. _Hippopotamus-ivory_.--This was at one time very extensively used. It was carved into the shape of the missing teeth, and was held upon a base; or it was carved into shape as a base upon which to rest human teeth. Most often it was used as a base for pivoting. Not infrequently a block was carved out which represented gum, teeth, and all, and partial dentures of this complex type were often so deftly fashioned as to be very realistic, the part representing the gum being colored. Unfortunately no dye nor color in the mouth could be made permanent. _Elephant-ivory_.--This was used for the cheaper grades of work, being less durable. _Bone_.--Bone was still more objectionable, and was used for only the cheapest work. Artificial porcelain teeth were first introduced in France in 1774 and in America in 1817. Those which were first made{335} were so large, awkward, rough, and ill-fashioned, without attempt to represent the gum, as to bear no comparison to the artistic products of to-day. They were intended for the most part for attachment to ivory bases. The artificial dentures made for George Washington were of this general character, and, although they called forth his encomiums in a letter to his dentist expressing his gratitude, they would pass for very shabby productions today. One of the greatest advances in dentistry was the introduction of gold bases as a substitute for the baseplates previously made of ivory or bone. This is distinctly an American invention, and is to be credited to Gardette, of Philadelphia, who produced the first bases of this kind in 1787. Since then other metals have been used only because cheaper, none having the valuable properties of gold.