GB484343A - Improvements in or relating to the manufacture of surgical protheses - Google Patents

Abstract

Surgical protheses, particularly dental protheses, are manufactured in the manner usually employed for working up rubber by mixing a solid, preferably comminuted polymerizate with a liquid monomeric or partially polymerized compound to produce a plastic, kneadable mass, filling a mould of the dental flask type therewith and solidifying the mass therein by polymerization of the liquid material. Suitable polymerizable compounds are vinyl and acryl compounds and styrol. A mixed polymerizate or mixtures of polymerizates may be employed for the solid material. Polymerization accelerators, e.g. hydrogen peroxide and benzoyl peroxide and regulators, e.g. turpentine oil, may be employed. Additions such as artificial or natural resins, softeners, soluble colours or insoluble pigments, fillers and cellulose derivatives, e.g. cellulose tripropionate or cellulose ethers, may be employed. Polymerization is effected at temperatures at which bubble formation does not occur. The mould may be lined with waterglass, gelatine, polyvinyl alcohol &c. Articles may be repaired in a manner similar to that employed for rubber protheses. In an example, an interpolymer of methacrylic acid methyl ester and acrylic acid butyl ester, in powdered form, is kneaded with a similar monomeric mixture, together with red and white pigments, to form a rubber-like mass which is then packed into a two-part gypsum dental mould, produced in the usual manner. After closing and pressing the mould-parts together, the mould is again opened and further material introduced to ensure complete filling after which the mould is again closed and heated, first to p 60 DEG C., then to 80 DEG C., and finally to 100 or 115 DEG C. In a further example, the solid and liquid components comprise acrylic acid methyl ester, acrylic acid nitrile, vinyl acetate and methacrylic acid methyl ester.