CAD/CAM Technology for Implant Abutments, Crowns, and Superstructures

The aim of the first systematic review was to answer the focused question “How do CAD/CAM implant-supported prostheses in patients with missing teeth and one or more dental implants perform compared to conventionally fabricated implant-supported prostheses when assessing esthetics, complications (biologic and mechanical), patient satisfaction, and economic factors?”

CAD/CAM technology that can be used to predictably facilitate the restoration of dental implants from single-unit cases to complex full-arch reconstructions is currently available. The techniques used to produce the CAD/CAM frames vary significantly between the different investigations.

The first described techniques were based on resin patterns placed in a laser scanner to feed information on the contour of the framework into a computer. An identical copy of the resin pattern was then milled out of one piece of titanium. Currently, it is possible to design a complete virtual prosthesis using computer-generated CAD/CAM parts without scanning a physical prototype.

For crowns, abutments, and frameworks, CAD/CAM technology is able to provide results that, based on the current literature, are comparable to that of conventional techniques when considering implant survival, prosthesis survival, and technical and biologic complications.

With respect to CAD/CAM technology for implant abutments, crowns, and superstructures, the following statements can be made:

• CAD/CAM technology has been successfully incorporated into implant dentistry.
• The clinical performance of implant-supported prostheses produced using CAD/CAM and conventional techniques is similar over the short term (mean: crowns, 1 year [1 to 1.1 years]; abutments, 3.5 years [1 to 5 years]; frameworks, 4 years [1 to 10 years]).
• The variability of CAD/CAM software and hardware used in fabricating implant-supported prostheses makes comparison difficult.
• The variability of outcome measures and material choices in investigations of CAD/CAM implant-supported prostheses makes comparison difficult.
• The short-term (mean, 3.5 years [1 to 5 years]) survival rate of individually customized CAD/CAM abutments is similar to that of conventionally fabricated or stock abutments.
• The short-term (mean, 4 years [1 to 10 years]) survival rate of individually customized CAD/CAM frameworks is similar to that of conventionally fabricated frameworks.

• The implementation of CAD/CAM technologies should lead to acceptable clinical outcomes.
• Continuous training for both the restorative dentist and technician is essential to successfully implement CAD/CAM techniques for the restoration of dental implants.
• There is continuous industry-controlled development in CAD/CAM devices, techniques, and materials. The dentist and technician should be aware that product hardware and software, as well as support, will change with generational advances.
• As the dentist remains responsible for treatment outcomes, it is recommended that he/she play an active role, together with the technician, to carefully control CAD/CAM processes and material selection.
• It is recommended that the dentist approve a virtual final prosthesis (virtual diagnostic wax-up) that dictates abutment/framework design.
• It is recognized that digitally derived prostheses can be remanufactured from stored data sets. It is recommended that digital data sets be stored/protected for this eventuality and that digital technology work platforms maintain programming compatibility/ transparency.