The invention is directed to a composition comprising a) compound (A) being characterized by at least the following features: comprising a backbone unit (U) comprising a tricylclic hydrocarbon moiety, two spacer units (S) each comprising a hydrocarbon chain (G) being directly connected to the backbone unit (U) via an urethane moiety, and at least two reactive groups (M) being connected to the hydrocarbon chain (G) via an ester linkage, with (G) being a non-branched hydrocarbon chain having a length of at least 3 carbon atoms, (G) not comprising ether moieties, and (M) being selected from acroyl and methacroyl, b) initiator (B) and c) optionally filler (C), the composition being a dental composition.