Keys to Predictable Digital Impressions.

Conventional impressions are the benchmark for any new replication technique due to the demonstrated accuracy of PVS and polyether impression materials.1 However, it is well known that throughout the impression process there are potential risks to final accuracy, including setting of the impression material, removal of the impression, and fabrication of the stone model.2-4 Despite the documented accuracy of PVS and polyether impressions, studies have repeatedly shown that most impressions sent to dental laboratories have some sort of deficiency. One study evaluated 193 FPD impressions made by 41 dentists immediately after they arrived at 11 dental laboratories and reported that 50.7 percent of all the impressions had voids or tears in the finish line area, 40.4 percent had air bubbles at the margin line, and 26.9 percent had both.5 Thus, although impression material has documented accuracy, making an accurate impression involves more than just the precision of the material.