Patent ID: 7538172

Claim:
A dental material being polymerizable by ring-opening metathesis polymerization comprising (i) at least one ruthenium complex bearing at least one N-heterocyclic carbene ligand or precursors which generate a ruthenium complex bearing at least one N-heterocyclic carbene ligand in situ; (ii) at least one cyclic olefin capable of metathesis; and (iii) at least one co-monomer, wherein the ruthenium complex is of the formula wherein: X 1 and X 2 are independently of each other Cl − , Br − or a substituted or unsubstituted phenolate anion; R 1 to R 6 are independently of each other hydrogen, C 1 -C 6 -alkyl or COOR, R being C 1 -C 3 -alkyl; R 7 and R 8 are independently of each other hydrogen, C 1 -C 10 -alkyl, C 6 -C 10 -aryl, or halogen; Ar is C 5 -C 10 -cycloalkyl, substituted or unsubstituted phenyl, or substituted or unsubstituted aryl, and the doffed line indicates a single bond or a double bond.