Marginal Accuracy and Fracture Strength of Conventional and Copy-Milled All- Ceramic Crowns

In this comparative in vitro study, the marginal accuracy and fracture strength of conventional and copy-milled In-Ceram crowns were examined. Anterior crowns with medians of 32.5 um for the conventional technique and 38 um for the copy-milled units had signifiantly smaller gaps than premolar crowns that had a median marginal gap of 45 um for both techniques. There was a significant difference in fracture strength only for anterior crowns. The study indicates that copy-milled In-Ceram crowns have clinically acceptable margins and fracture strength and reduce laboratory fabrication time.