Silver-plated dies. Part II: Marginal accuracy of cast restorations.

This laboratory study simulated actual clinical crown fabrication. Crowns were finished to the point of clinical delivery with stone and silver-plated dies made from representatives of the four major groups of elastomers. A clinically acceptable technique for judging crown margin accuracy was used, and numerical scores were assessed. Scores were analyzed statistically to compare die types, materials used, and types of discrepancies. Results of this study indicate the following information about the materials tested. The marginal accuracy of crowns fabricated on the silver-plated dies is statistically as accurate as that of crowns fabricated on stone dies in all cases and significantly more accurate in some instances. Silver-plated dies fabricated from Reprosil produced more accurate crowns than all other dies tested. Acceptable crown margins were obtainable from either stone or silver-plated dies when judged by clinical criteria. Silver-plated dies can be used without compromising crown margin accuracy.