Abstract: An impression composition which is based on an aziridine-free composition which can be vulcanized at room temperature, and which comprises wax is provided according to the invention. The wax increases the dimensional stability of the composition during mixing and curing. The invention furthermore provides a kit for the preparation of such compositions and a process for the preparation of the wax-containing components of these kits. The wax is dispersed throughout the composition and is prepared by shock-cooling. The wax forms a crystalline network.

Abstract: (Methy)acrylic acid esters of the general formula(Mo).sub.n --[--A--O--CO--CH.sub.2 --O--CH.sub.2 --CH.sub.2 --O--CH.sub.2 --CO--O--].sub.x --A--(OM).sub.nare described whereinA is an alcohol radical having at least 4 chain atoms between two junction sites.M is CH.sub.2 .dbd.C(R.sup.1)--CO wherein R.sup.1 stands for hydrogen or methyl,n is 1 or 2, andx is 0.3 to 3.These esters are suited for the preparation of dental compositions.

Abstract: The physical properties, especially resistance to abrasion, to bending and to pressure, of plaster models for use in dentistry are improved in that a plaster model obtained in a manner known in the art is impregnated with (a) at least one photopolymerizable ester of acrylic and/or methacrylic acid, (b) at least one photopolymerization initiator, and (c) optionally at least one photopolymerization activator--(a), (b) and (c) being present in liquid or dissolved state--and the impregnated plaster model is irradiated with light suitable to initiate photopolymerization by the photoinitiator.

Abstract: Imidazoles in dissolved form act as an agent for retarding the gelation of the polymerization of aziridine compounds initiated with sulfonium salts. The composition is particularly useful in dentistry applications, such as in the preparation of impressions and provisional denture parts.