CAD/CAM dentistry is a field of dentistry and prosthodontics using CAD/CAM (computer-aided design and computer-aided manufacturing) to improve the design and creation of dental restorations, especially dental prostheses, including crowns, crown lays, veneers, inlays and on lays, fixed bridges, dental implant restorations, dentures (removable or fixed), and orthodontic appliances.
CAD/CAM complements earlier technologies used for these purposes by any combination of increasing the speed of design and creation; increasing the convenience or simplicity of the design, creation, and insertion processes; and making possible restorations and appliances that otherwise would have been infeasible. Other goals include reducing unit cost and making affordable restorations and appliances that otherwise would have been prohibitively expensive.
However, to date, chairside CAD/CAM often involves extra time on the part of the dentist, and the fee is often at least two times higher than for conventional restorative treatments using lab services. CAD/CAM is one of the highly competent dental lab technologies.
Typically CAD/CAM dental restorations are milled from solid blocks of ceramic or composite resin that closely match the basic shade of the restored tooth. Metal alloys may also be milled or digitally produced.
After decayed or broken areas of the tooth are corrected by the dentist, an image (scan) is taken of the prepared tooth and the surrounding teeth. This image, called a digital impression, draws the data into a computer. Proprietary software then creates a replacement part for the missing areas of the tooth, creating a virtual restoration. This is called reverse engineering. The software sends this virtual data to a milling machine where the replacement part is carved out of a solid block of ceramic or composite resin. Stains and glazes are fired to the surfaces of the milled ceramic crown or bridge to correct the otherwise monochromatic appearance of the restoration. The restoration is then adjusted in the patient’s mouth and cemented or bonded in place.
As in other fields, additive manufacturing (3D printing) first entered CAD/CAM dentistry in the form of laboratory experiments, but its use has since expanded; and chairside use, although not yet widespread, is advancing.