CAD/CAM Manufacturing in Prosthetic Implant Dentistry

Computer-assisted design (CAD) and computer-assisted manufacturing (CAM) have been applied in implant dentistry for the design and fabrication of prosthetic frameworks and prosthetic abutments.

A number of perceived advantages of these techniques were identified by the group. These included a potential for improved quality and precision by controlling the processing environment, and using specific software to determine the material dimensions required based on the physical and mechanical properties. It was anticipated that these advantages would result from the enhanced consistency of the more homogenous material and a shift from the traditional individual laboratory processes to one that is more industrialized. This should facilitate a minimized inventory and allow for remote communication and collaboration between clinicians, technicians, and other parties, with a potential reduction in cost.

Similarly, the group identified a number of perceived disadvantages of CAD/CAM manufacturing, including the cost and maintenance of equipment, along with the education and training necessary for its operation, and the potentially short life spans of the software and hardware. Due to the industrialized process there would be a lack of clinician control over some of the specific technical outcomes, and as some of the materials and material combinations are still clinically undocumented and possibly subject to inconsistency, concern was also expressed about their use.

The systematic review by Kapos et al was discussed by the group members, who suggested that while preliminary evidence for CAD/CAM in implant dentistry appears promising, the review of the literature concerning its use for the fabrication of frameworks and abutments fails to provide meaningful clinical evidence of safety and effectiveness associated with the routine use of this technology. The currently available information is insufficient to provide data for long-term documentation.

At present, technical developments are outpacing clinical research in the field of CAD/CAM implant abutments and frameworks, and it is recommended that users of this technology acknowledge this limitation in interpreting clinical research data. Clinicians and technicians also need to be aware that new materials and techniques are now being combined in a manner that has not been previously documented.

With the information available to the group from the systematic review by Kapos et al, it was felt that for clinical situations requiring highly individualized components, CAD/CAM can be considered the method of choice. Similarly, where the material of choice is zirconia or titanium, CAD/CAM could again be the preferred option. However, the steep learning curve necessary for the use of CAD/CAM technology requires both the clinician and the technician to undertake appropriate training prior to implementation of the system. Furthermore, the rapid progression of this technology necessitates continuous training to ensure optimal outcomes and, due to the high set-up costs, it is recommended that users have an understanding of the product support requirements for their system of choice.

While there is preliminary “proof of concept” that CAD/CAM technology is viable, it is recommended that clinicians be cautious in its clinical application, since these newly reported techniques provide no evidence for long-term clinical performance.