CAD CAM in Removable Prosthodontics

After nearly 80 years of minimally changed methods and protocols to fabricate complete dentures (CDs), the first commercially available computer-aided design/computer-aided manufacturing (CAD/CAM) denture systems heralded a new era in removable prosthodontics. The complexity of CD fabrication procedures is the main reason digital technology has become available only recently for CD prosthodontics compared to other fixed prosthodontic restorations. Computer-aided technology is a broad term that implies the use of computer skills to aid in the design, analysis, and manufacture of products. It can either involve additive manufacturing (such as rapid prototyping) or subtractive manufacturing (such as computerized numerical control [CNC] machining). Additive manufacturing, or 3-dimensional (3D) printing, uses images from a digital file to create an object by laying down successive layers of a chosen material. Subtractive manufacturing uses images from a digital file to create an object by machining (cutting/milling) to physically remove material and achieve the desired geometry. In prosthodontics, the subtractive procedure, computer aided design and computer-aided manufacturing (CAD).