[Does temporary cementing have an effect on the bond strength of definitively cemented crowns?].

To establish whether or not temporary cementing with zinc oxide-eugenol (ZOE) cement affects the bond strength of the subsequent zinc phosphate cement, 60 standardized metal blocks with cylindrical drill holes were produced. 50 specimens were coated with ZOE cement and subjected to different cleansing techniques (mechanical, with alcohol or organic solvent, soap, Al2O3) in groups of ten. After examination of the cleansed surfaces under the light microscope, amalgam cylinders manufactured according to a standardized procedure were cemented into the cavities using zinc phosphate cement and pressed out. Only the Al2O3 jet-cleaned surfaces were free of ZOE cement residues. With high statistical significance the knock-through test revealed lower bonding strength values for the specimens cleaned either with alcohol or organic solvents.