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March 2009 | Dental Lab Products
Forward trends: Digital Outsourcing


CAD/CAM: The next generation

An interview with Siegbert Witkowski, MDT, CDT

By Pam Johnson

DLP: How do you see CAD/CAM technology changing the face of the laboratory industry in the coming years?

Witkowski: I believe the volume of restorations made by conventional methods will shrink.

CAD/CAM systems are getting more and more sophisticated and precise at producing the needed restorative parts that were traditionally produced by hand. I also see a shift in objectives from restorations made by hand versus those produced by machine. Many dental professionals are more interested now in low cost, high production than in the precision and reliability of hand-made restorations.

One of the newest trends that concerns me is that of manufacturing facilities becoming the agent for the dentist, skipping over the services of the traditional dental laboratory. In Germany, we have a manufacturing center that is producing restorations on an industrial basis using new technologies. Owned by an investment group, the facility is producing and selling all-ceramic crowns, inlays, and onlays at such a low cost that a dentist couldn’t produce a restoration chairside at this price. Companies like these are forging a new concept in dental technology.


DLP: In terms of CAM process, what can we expect to see in the near future and further down the road?

Witkowski: Looking at milling and grinding CAM technologies, we are seeing very large, industrial, professional units appearing on the market. These large 5-axis units can fabricate very complicated structures such as screw-retained superstructures on implants. Because these robust milling units are so expensive, they are located only in large production centers. This is, and will continue, creating a shift away from the small laboratory to the large industrial production and manufacturing centers.

A technology receiving increased interest in the CAM arena is stereolithography (SL). Stereolithography utilizes a liquid polymer to produce 3D diagnostic and surgical splints for implantology as well as waxups for casting and pressing restorations.

Most recently and more importantly, 3D stereolithography is being used to manufacture working models from data captured by digital impression-taking devices. For the most part, the digital information captured by the dentist is not being sent directly to the laboratory but rather to the manufacturer for fabrication of a working model via stereolithography and/or milling process. There is a buildup of networks out of production centers for “digital” models. At this point, several systems following this concept will be presented at the International Dental Show (IDS) in Cologne, Germany. The questions still unanswered are: Who will distribute the data, and who will produce the restorations. This is a major topic over the next several years.

This same SL technology will in the very near future be able to build up temporary restorations from a tooth-colored liquid monomer. The laboratory would design the temporary using CAD software and electronically transmit the data to a 3D printer. The finished temporary is then sent to the dentist for try-in. This is very close to reality.

Other researchers are working on 3D printing composite resins. The printer operates much like the bubble jet printer in your office. But imagine instead of layering ink on paper the machine would use composite, ceramics, or acrylic. Each very thin layer of the ceramic powder being printed would be laser sintered until the final restoration form is revealed. This research has a way to go yet. We won’t see a 3D ceramic material printing technology on the market for the next 10 years or so.

Another emerging technology is the femtosecond laser concept for cutting zirconia and other ceramic or metal materials. It is still very young and needs much more development. I just spoke to the research group last week, and the estimate is another 5 to 10 years before we realize a working concept coming onto the market. Currently, the technology works, but is too expensive to use in dentistry at the moment.

Siegbert Witkowski, MDT, CDT, is Chief of Dental Technology at the University Hospital Freiburg School of Dentistry, Department of Prosthodontics. Author of several books and numerous journal articles and Editor-in-Chief of a monthly journal, Mr. Witkowski is a member of several national and international organizations, is a well-known lecturer, and acts as a consultant to several manufacturers. His primary interests are esthetics, new crown systems, CAD/CAM, and rapid manufacturing.

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