You do NOT have to dye the restoration or anything, after it comes out of the milling unit you just have to grind off the sprew and polish it and it is good to go.
If you want to have a precise shade match in an esthetically critical area (anteriors, 1st PM, some 2nd PM, and even some Max. 1st molars) you actually DO have to utilize custom staining with current cerec technology. This is necessitated by the limited variety of block shades available, and is further complicated by the monochroma and opacity of the blocks. This easily eliminates any time savings of cerec over lab ceramics, assuming you are going to stain all your cerecs in order to obtain equivalent esthetics to the lab processed ceramics.
If I were a GP I would not be satisfied with this technology yet. I still think it is worth the extra (short) cementation appointment to get better margins, better shade, and better anatomy as can be easily acheived by a variety of stacked or pressed laboratory ceramics.
That said, there are plenty of GP's out there that will settle for the lesser esthetics, poorer shades, less detailed anatomy, and more open margins of cerec in exchange for the slight increase in productivity.
But then there is the whole aspect of overdiagnosing lesions in order to justify the larger preps necessary to utilize the cerec machine that you have already signed up for. You know, those moderate sized composite fillings that are too small to replace with a cerec, but you could make them a little bigger if you "needed" to and then maybe you would actually have to replace a cusp. Ooops, now its an Onlay! And since you kinda need to do 15-20 cerecs a month to pay the lease, well . . . You get my point.
When someone is using Lab porcelins, this little quandry is less likely to come up (but still could).
