Abstract: The invention relates to a shaped body and a process for its production by means of a radiation-induced printing process, characterized in that the shaped body is produced from a liquid or viscous material which contains a starting component with cycloolefinic groups, a thiol with at least two thiol groups per molecule and an initiator and/or catalyst for the light-induced thiol-ene addition reaction between the thiol groups and a double bond of the cycloolefinic groups, and the solidification takes place by directing light from a radiation source onto a region of a surface of a substrate, a layer of the liquid or viscous material located there being subjected to organic polymerisation by the action of radiation and thereby solidified, whereupon further layers of the liquid or viscous material, which are each located on the layer of the most recently solidified material, are successively solidified with the aid of this radiation source.

Abstract: A dental material is described which is characterized by a content of silicic acid condensates of norbornene or mercapto silanes, and which, after thiol-ene polymerisation with suitable reactants, shows only slight polymerisation shrinkage and produces polymerisates with high mechanical strength.

Abstract: The invention relates to self-curing systems based on polymerizable and hydrolytically condensable or condensed silicon compounds. The systems according to the invention comprise one or more components which contain starter and/or activator systems, at least one component of the system containing a silicon compound of the formula I or Ia, or a precondensed form thereof,{X.sub.a R.sub.b Si?R'(A).sub.c !.sub.(4-a-b) }.sub.x B (I){X.sub.a R.sub.b Si?(R'A).sub.c !.sub.(4-a-b) }.sub.x B (Ia)The invention furthermore relates to activators in the form of silane-bonded tertiary amines of the general formula IX or X.