I believe it works something like this;
-Scan a physical model or accept a virtual model created by a dentist who owns an intra-oral scanner and he/she can then send you an stl file via the internet
-Design a full contour crown using CAD
-Software automatically creates two files, one is the under-stucture or coping the other is the over-lay portion
-The coping portion or file is then either milled from metal / milled from sintron and then sintered / milled from zirconia and then sintered / or milled or printed in wax then cast and finished
-The overlay portion is then milled or printed from wax...See more and then placed over the completed coping, sealed using a heated instrument, sprued up and invested
-The ring is then placed in the burn-out oven
-After burning out the ring is placed in a pressing furnace that melts ingots of ceramic material and then presses them over the coping.
-Devest, stain and glaze, done ! 100% digital !!! F@#$ me runnin,...Youch !!!
ADVICE - GO DIGITAL or forget about this business ( Don't shoot the messenger )