Tough, Long-Lasting Dental Composites

A dental composite comprising:

• (A) a matrix comprising a resin with the following structural element (Ib)
• wherein the residues and indices have the following meaning:
• R is an open-chain and/or cyclic alkylene group, arylene group, or alkylene arylene group with 1 to 10 carbon atoms, respectively, and is optionally interrupted by one or several oxygen or sulfur atoms or carboxyl or amino groups or optionally carries such atoms/groups at an end remote from the silicon atom;
• R1 is an open-chain and/or cyclic alkylene group, arylene group, or alkylene arylene group with 1 to 10 carbon atoms, respectively, substituted with the urethane group shown in the formula (Ib), and is optionally interrupted by one or several oxygen or sulfur atoms or carboxyl or amino groups or optionally carries such atoms/groups at one end;
• R′ is an open-chain and/or cyclic alkyl group, alkenyl group, aryl group, alkyl aryl group, or aryl alkyl group with preferably 1 to 20 carbon atoms;
• B and B′ are the same or different and have the meaning of a straight-chain or branched organically polymerizable group with at least one (meth)acrylate residue and thus at least 3 carbon atoms;
• R3 are the same or different, wherein at least some of the R3 have the meaning of a bond to another silicon atom and, when not a bond to another silicon atom, are a hydrogen atom, an alkyl group with 1 to 10 carbon atoms, or a bond to another metal atom that can be incorporated into silicic acid hetero polycondensates;
• a is 1 or 2 and b is 0 or 1;
• and
• (B) is a nanoparticulate filler.