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 microns for the conventional technique and 38 microns for the copy-milled units had significantly smaller gaps than premolar crowns that had a median marginal gap of 45 microns for both techniques. There was a significant difference in fracture strength only for anterior crowns. The study indicates that copy-milled In-Ceram crown have clinically acceptable margins and fracture strength and reduce laboratory fabrication time.