Prostheses and processes for their production

A process for the production of a dental prosthesis comprises disposing a paste or viscous solution which polymerizes at room temperature or a slightly elevated temperature between a model and a base plate, pressing the base plate so that the paste or solution fills all the interstices between the base plate and the model and allowing the paste or solution to polymerize to form a lining on the base plate. A model is prepared after taking an impression of the jaw. The base plate is cut to the shape of the model from a sheet of suitable synthetic resin material. The base plate is softened by boiling water and shaped to the model, the shape being made permanent by immersing in cold water. A suitable lining mixture is then applied to the tissue side of the base plate which is then pressed on the model so that the mixture fills the interstices between the base plate and the model. The lining mixture polymerizes at room temperature in a short time. Teeth of porcelain or polymethyl methacrylate are affixed to the plate using the same mixture as for the lining. The polymerized parts require finishing and polishing. In cutting the base plate a pattern in tin foil cut to the model may be used. In shaping the base plate to the model the hands may be protected from the heat by placing a foil of cellulose acetate over the base plate. The plastic mixture may be shaped in the mouth of the patient which is protected by greasing with "Vaseline" (Registered Trade Mark). The base plate is made of copolymers of methyl methacrylate and butadiene or its derivatives, methyl methacrylate or vinyl chloride and acrylates or methacrylates the alcohol radical of which contains more than three carbon atoms or polymethyl methacrylate plasticized with benzyl-butyl adipate or suitable phthalates. The lining mixture is made from mixtures or viscous solutions of polymeric and monomeric vinyl compounds such as polymeric and monomeric methacrylate or solutions of polymethyl methacrylate in methyl methacrylates containing Redox systems. Styrene, acrylonitrile or compounds having at least two polymerizable double bonds, e.g. divinyl benzene or ethylene glycol dimethacrylate or polyfunctional vinyl compounds may be added to the materials of the base plate. Specification 558,470 is referred to.