Comparison of accuracy of soldering indices for fixed prostheses.

lh e assembly of fixed prostheses requires a number of steps. Each must be performed with meticulous care to maintain the individual unit of the prosthesis in a precise relationship. The ultimate product is an accurately soldered assembly \vhich can be seated correctly on the abutments. Studies found in the literature refer to the accuracy of solder joints, but no direct comparison of the accuracy of the two bridge-indexing methods commonly used has been made. Stackhouse’ determined soldering accuracy with the use of quick-set plaster indices. Patterson’ described a technique for soldering using self-polymerizing (cold-curing) acrylic resin indices, but he did not validate its accuracy. The purpose of this study was to compare the accuracy of impression plaster with cold-curing acrylic resin indices in the transfer of crowns from their abutment dies in preparation for the soldering of tixed partial dentures. The effect of variations in technique and elapsed time from indexing to investment were also measured.