Compositions for dental restoration

Claim 1

A combined chemical-/light-polymerization type composition for dental restoration consisting of a formula A consisting essentially of (a) an ethylenically polymerizable unsaturated compound, (b) a photo-polymerization initiator and (c) a reducing agent, and a formulation B consisting essentially of (d) a filler and (e) an organic peroxide, said formulations A and B being separately packaged and designed to be mixed for use, wherein said photo-polymerization initiator consists of one or two or more ketal base compounds expressed in terms of the following formula 1: ##STR9## wherein X is H, Cl, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, A is a six-membered aromatic group, and R is an alkyl group having 1 to 10 carbon atoms, an aralkyl group having 7 to 9 carbon atoms or C n H 2n O m R' in which n is an integer of 2 to 5, m is an integer of 1 to 5 and R' is an alkyl group having 1 to 5 carbon atoms, and one or two or more benzoin alkyl ether base compound of the following formula (4) ##STR10## wherein R is an alkyl group, R' is selected from the group consisting of a hydrogen atom, an alkyl group, and a halogen atom, and one or more R" may be present on the phenyl rings in that formula, or R" may be selected from the group consisting of an alkyl group, an alkoxy group, a halogen atom and an alkylamine group.