CEREC is an acronym for Chairside Economical Restoration of Esthetic Ceramics. Here is a basic description of the process:
First your tooth will be prepared for the crown, inlay, onlay or veneer. It will then be coated with a white powder and imaged by a 3D imaging camera that is uploaded into the CEREC computer.
Once in the computer, 3D CAD (Computer Aided Design) software from CEREC is run in various modes to design the restoration model. The computer is interfaced to the milling machine and controls the entire sculpting process which uses precise diamond head cutters to cut the porcelain block - one that is a chosen match to the tint of your current and surrounding teeth.
To keep the temperature down on the cutting procedure, water is sprayed throughout the chamber.
When completed - usually within around 15-20 minutes - the restoration is bonded to the tooth using a resin. The final result is a strong porcelain replacement that not only looks natural, but feels natural.