les dents, qu’ils aillent aux vieux dentateurs, et non aux jeunes qui n’auront encore reconneu leurs fautes.”[308] [Illustration: FIG. 63 Two gum lancets and a trifid lever called “poussoir” (Ambroise Paré).] But let us now return to our subject. After the extraction of a tooth, it is necessary—says Paré—to leave the wound to bleed freely, so that the part may get rid of the morbid humors; then the gums and the alveolus must be pressed, on both sides, with the fingers, to readjust the socket, which will have been widened and sometimes even broken in extracting the tooth. After this, the patient should rinse his mouth with oxycrate; and when the weather is cold and windy, the patient should take care to avoid fluxion in the other teeth. The following chapter speaks, “_de la limosité ou rouillure des dents, et de la manière de les conserver_.” After meals the mouth must be rinsed with water and wine, or with water with a little vinegar added to it, and the teeth cleaned from all residues of food, so that their putrefying may not spoil the teeth and make the breath fetid. An earthy yellowish substance, like rust, often forms on the teeth from want of cleanliness and also when they are not used to masticate; this substance corrodes the teeth, just as rust corrodes iron. It is necessary to remove this substance, by scraping the teeth with small instruments suitable for the purpose, and then the teeth themselves must be rubbed with a little aqua fortis and aqua vitæ mixed together, to take away what the instruments have not been able to remove. In order to preserve the teeth it is necessary, besides, to rub the teeth frequently with appropriate dentifrices. Among these the author mentions simple bread crust, burnt and reduced to powder. In Chapter III of Book XVII he speaks of artificial teeth. Sometimes, says Paré, by the effect of a blow, the front teeth are lost; this not only constitutes a deformity, but is also the cause of defects of speech. Therefore, after the necessary treatment, when the gums are hardened, the lost teeth must be substituted with artificial ones made out of bone, ivory, or the teeth of the _Rohart_,[309] which are excellent for this purpose; and the artificial teeth must be tied to the neighboring ones with gold or silver wire. [Illustration: FIG. 64 The palatine obturator with sponge of Ambroise Paré.]