Processes for Avoiding the Change of Color of Plastic Substances used in the Manufacture of Denture Apparatus.

Реферат: 4440. Eilertsen, L. Feb. 25. Teeth, artificial.-To prevent change of colour in the plastic substances used in the manufacture of denture apparatus, insoluble and vitriflable colours or enamels are used, and antiseptics such as salol, iodoform, and the like, together with perfumes, are added to the plastic paste. In order to prevent the colour from changing due to an alteration in one or more of the component materials, such as the alteration of the guncotton in celluloid, the celluloid is covered with a substance such as india-rubber, gutta-percha, gelatine, caseine, &c., less likely to change. A solution of the rubber in a mixture of its solvents and of the solvents of celluloid, is used for connecting the rubber to the celluloid, the rubber being afterwards vulcanized cold in a solution of carbon bisulphide and sulphur chloride containing antiseptics and perfumes. Gelatine may also be applied to the surface of the celluloid, and treated with alcohol and the vapours of formic aldehyde or formol, or hardened in any other manner.