GB254075A - Improvements in or relating to the manufacture of artificial teeth - Google Patents

Abstract

254,075. Jackson, W. J. Mellersh-, (Dentists' Supply Co.). May 27, 1925. Teeth, artificial. - Artificial teeth are formed by first moulding a portion thereof from porcelain material, between hard surfaces, and then moulding between a hard surface and the surface of the already moulded material the balance of the porcelain material required to complete the tooth structure, and heating to vitrify the two parts, into a unitary porcelain tooth. In one form, Figs. 4 - - 6. part 16 of the porcelain material is formed between moulds 3, 12, to give a tooth portion tapering from the incisal to the cervical end, and is then dried by heating the moulds. The body portion 11<a>. which is made from porcelain material 11 of darker tint, is then moulded between the surface of this portion 16 and a third mould 2, Fig. 5, the moulds 2, 3 being clamped together. Anchor elements 10 may be embedded in the body material and holes 9<a> for the pins provided, or the pins may be directly moulded in the material without the separate anchors, or holes or depressions without anchors or pins may be moulded therein. The moulds are heated to bake the material and the biscuited tooth then removed and converted into porcelain by heating to the required temperature, the parts 16 and 11<a> fusing and blending together. The moulds 2, 3, 12 may be formed to make several teeth simultaneouslv and are provided with registering pins 6 and sockets, and with contact surfaces 5, 5<a> which engage when the moulds are brought together. In another form, the third mould is adapted to form the body portion 11<a> first, the remaining portion of the tooth being moulded between this portion, in the mould 2. and the mould 3. The moulds 12 may also be constructed by having the parts 13, which are used to form the part 16, made on separate blocks 20, Fig. 11. These blocks may be registered correctly with mould part 3 and the mould body 12d then placed over the blocks 20 and attached thereto bv solder 22. In a further form, the third mould is dispensed with and blocks 13<d>, Figs. 9 and 10, are placed in mould 2 and have pins 18 registering with holes 19 in the mould, and the part 16 of the tooth is then formed by means of the moulds 2, 3. The block 13d is then removed, and posts and anchors and the body material 11 inserted in mould 2 and the formation of the tooth completed in the former way. The block 13d may be adapted to co-operate with mould 2 so that the body portion 11<a> is first formed.