Verfahren zur Herstellung von kuenstlichen Zaehnen nach dem Pulver-Fluessigkeits-Verfahren

摘要

A process for producing artificial teeth comprises (i) preparing a novel bead polymer from a corresponding monomer by addition polymerization in the presence of at least one organic fluorescent compound and a non-peroxidic polymerization catalyst (ii) mixing said novel fluorescent compound-containing bead polymer with a second bead polymer not containing a fluorescent compound, and a monomeric addition polymerizable liquid to form a paste and (iii) polymerizing the paste in a heated mould. Both bead polymers used are preferably methyl methacrylate polymers and the monomeric liquid is preferably methyl methacrylate; the catalyst may be an azodinitrile, e.g. azoisobutyric acid dinitrile. In step (iii) either a peroxidic or non-peroxidic catalyst may be used; benzoyl peroxide is an example of the former type. An inorganic pigment may also be included in step (ii), e.g. titanium dioxide or cadmium yellow. In an Example, the first bead polymer is a methyl methacrylate-ethyl acrylate copolymer and the second bead polymer is polymethyl methacryate; the first polymer is obtained by polymerizing the corresponding monomers in an aqueous solution of poly-N-vinyl-pyrrolidone in the presence of azodiisobutyric acid dinitrile and an organic fluorescent compound; step (iii) of the process is conducted at two different pressure and temperature levels.