How does the accuracy of a crown made from a digital scan compare to a crown made from an impression?

In a study by THE DENTAL ADVISOR, the overall fit of the Lava C.O.S. crowns was superior to that of the impression crowns, resulting in the cementation of 71% of the Lava C.O.S. crowns and 29% of the impression crowns (THE DENTAL ADVISOR Research Report, No. 22, June 2009).