The present invention relates to a kit comprising at least two pastes, A and B. Paste A contains at least one monomer for radical polymerization； and at least one barbituric acid derivative as polymerization initiator. Paste B contains at least one monomer for radical polymerization； and at least one heavy metal compound as polymerization accelerator that is selected from heavy metal salts and heavy metal complexes. Paste B contains less than 0.01% by weight, relative to the total weight of paste B, of a peroxide； at least one of the pastes A and B contains-at least one filling agent that is poorly soluble or insoluble in the monomer for radical polymerization in either paste A or B respectively； and at least one of the pastes A and B contains at least one inorganic halide salt.
