Impression materials and electrodeposits. Part II: Electrodeposits

1. Of 13 substrate/electrodeposit combinations tested, the six satisfactorily completed were modeling compound/copper, Permlastic/silver, Elasticon/nickel, Polyjel/silver, Polyjel/nickel, and President/copper. 2. The seven remaining substrate/electrodeposit combinations could not be completed because of pitting, discoloration, or high stresses within the electrodeposits. 3. In some instances, the electrodeposit dimensions were significantly different from those of the substrate. The combination with the largest substrate/electrodeposit difference was that of President/copper. 4. The combinations which demonstrated the least change from the master die were Polyjel/nickel and Elasticon/nickel. The completed nickel electrodeposits were not significantly different from each other nor from the master die. 5. The ultimate length of the electrodeposit in some combinations appeared to be dependent upon the substrate temperature, water sorption, polymerization shrinkage, and stresses within the electrodeposit. 6. These results contradict those who maintain that die inaccuracy is due solely to the impression material and support those who believes that both the impression material and the electrodeposit itself can contribute to die inaccuracy.