CAD/CAM : Computer Aided Design/Computer Aided Manufacturing

Traditional crown/onlay fabrication entails taking an impression of the prepared tooth; having a lab prepare a model off of which they prepare a wax replica of the crown; casting the crown in metal  and/or hand-stacking porcelain to produce an all metal crown, a combination porcelain fused to metal crown, or an all porcelain crown; when the labwork is completed, the patient returns to have the temporary crown removed and the permanent crown cemented.

CEREC CAD/CAM technology uses digital imaging to, essentially, take a 3D optical image of the prepared tooth, producing a virtual model on which the dentist can immediately design the crown/onlay.  The milling unit of the CEREC then fabricates the crown/onlay from a block of highly dense pressed porcelain (with shade selections that extend beyond the standard shade guides).  With a quick polish, the crown/onlay is ready for final cementation.  Although more complex cases may entail temporization of the prepared tooth to allow the doctor additional time for designing or custom shade matching the restoration, most single unit restorations are completed in one appointment. Many dental labs are using the CEREC to produce all porcelain crowns due to advantages in material strength as well as the enhanced accuracy of optical impressions.

There is more that we could say, but, since a picture is worth a thousand words, please click on the following link to view a short video of a CEREC restorative appointment  Cerac Link