The term CAD/CAM in dentistry has become synonymous with computer-aided manufacturing. CAD stands for computer-aided design and CAM is the abbreviation for computer-aided manufacturing. CAD/CAM is used in many manufacturing industries, for example in the automotive and aircraft industries, and model making.
But digital technologies also greatly facilitate the workflow in the manufacturing of dentures. In essence, technological know-how is just as important in dentistry as are technological skills and knowledge of materials science.
What does CAD/CAM mean in denture manufacturing?
In dentistry, computer-aided design (CAD) means the virtual construction of a tooth restoration on the computer. Computer-aided manufacturing (CAM) refers to the actual making a dental prosthesis using automated milling or grinding processes, or by using a 3D printer.
Based on a digital data record of the patient’s mouth and teeth obtained by a mouth and model scan, the dental technician and/or the dentist use special software to ‘construct’ the denture. This is the CAD part of the process, and can, for instance, be the framework for a bridge, or an anatomically complete crown.
This design data is transmitted to a milling or grinding machine, or a 3D printer, as an STL file (which stands for stereolithography). Here, the CAD data is utilised to physically make the corresponding object during the CAM part of the process. Once the machine has created the object, the final finishing-off of the dental prosthesis will be done by hand. For instance, the dental technician will veneer a bridge framework by hand with a tooth-coloured ceramic. Or he will paint the monolithic full-contour crown manufactured in the CAD/CAM process to match the colour of the patient’s teeth exactly.
CAD/CAM manufacturing methods
In brief, CAD/CAM production in dentistry can be divided into subtractive and additive manufacturing. In the case of subtractive technology, the CAD design is milled out of a material blank, or ground into the correct shape by removing material. Additive technology, however, refers to a process whereby material is built up, for instance where the computer design is implemented by using 3D printing.
Advantages of manufacturing using CAD/CAM technology in dentistry?
Dentures are medical devices that require great precision during the manufacturing process. The manual skills of the dental technician is greatly enhanced by CAD/CAM technology. Other advantages include a high level of accuracy and a product that is consistently of excellent quality. Some of today’s extensive variety of advanced materials can only be used by applying CAD/CAM technology, as is the case with zirconium oxide.
Digitization in the dental laboratory or dentist practice also allows networking with other digital dental technologies.
For example, digital X-ray data, DICOM, can be used in conjunction with the data about the patient’s mouth and teeth contained in an STL file. This means that a realistic virtual image of the patient’s jaw and teeth can be created. The dentist can then use this to plan the positioning of dental implants, for example.
Another example is where the data of a patient’s mouth is combined with the data contained in a facial scan, or a portrait photograph. This enables the dentist and/or the dental technician to access a virtual 3D model of the patient’s face, jaws and teeth. They are then able to have a detailed and in-depth discussion with the patient about tooth position, shape and colour by using the virtual 3D image.