Table of Contents

Continuing Education
Periodontics

Inside Dentistry

September 2008, Volume 4, Issue 8
Published by AEGIS Communications

Question: Is CAD/CAM Technology for Dentistry Here To Stay?

Allan G. Farman, BDS, PhD, MBA, DSc; Gregg Helvey, DDS; Edward A. McLaren, DDS

Dr. Farman
Computer-assisted design and manufacture is not only here to stay, but will inevitably replace “traditional” methods for restorative dentistry in the mid to distant future. In time, the dentist will not be a sculptor/artist relying on hand instruments held by gloved fingers, but rather an architect/computer engineer using high-technology methods for greater precision in tooth preparation and restoration.

CAD/CAM using the CEREC system (Sirona Dental Systems, LLC, Charlotte, NC) has sustained interest and use over a decade or so for tooth restoration manufacture at chairside. The introduction of cone beam computed tomography (CBCT) has provided the basis for production of surgical positioning stents and anatomic models by several third-party production centers. With the reduced price of printing devices for rapid prototyping, the production of these models and stents will inevitably move to the individual dental practice environment. Further, some orthodontic tooth movements are now possible using Invisalign® (Align Technology, Santa Clara, CA), a system that produces clear stents using CAD/CAM technology based upon visible light scanning of dental models.

Undoubtedly, CAD/CAM for dentistry will expand as technology with greater visible-light coverage of the oral structures than is presently practical for optical impressions develops to replace traditional physico-chemical impression methods. There is also need for developing better robots to take the dentists’ hands out of the patient’s mouth to the furthest extent possible.

Regarding use of CBCT as a replacement for impressions, this is somewhat problematic in view of the spatial resolution necessary for sealing restoration borders being an order of magnitude or greater than presently achievable. Very likely, the future will be a fusion of CBCT and optical impressions of key tooth details.

The American Dental Association (ADA) Standards Committees of Dental Materials and on Dental Informatics are presently looking to interaction to cover the topic of CAD/CAM. The materials necessary for CAD/CAM restorations are within the domain of the Dental Materials Committee, while the issues of standards for imaging are within the domain of Dental Informatics. Discussions are pre-sently in process with both Committees expecting rapid growth in CAD/CAM applications within dentistry.

Dr. Helvey
Twenty years ago, CAD/CAM dentistry was born in the dental office with a stand-alone machine called CEREC. There were many skeptics about the success of this mode of restorative procedure. However, Sirona, the manufacturer, had a vision of the future and continued to upgrade the product to its present 3D version. That same vision is now shared by many other companies—so much so that they are investing time and millions of dollars into the development of precision computer-based restorative care.

Digital dentistry has expanded greatly in the last several years. Think back to when IBM was the only computer company, and then to how many computer manufacturers there are today. Computer technology has altered long-established manual procedures in the laboratory as well as the dental operatory. Digital impressions will replace traditional methods. The data will be sent electronically and be in the hands of the laboratory technician before the patient is out of the chair. No more packaging impressions, opposing models, and bite registrations that can be lost or destroyed in transit. The laboratory will have eliminated the labor-intensive and time-consuming process of pouring models, ditching dies, and manually fabricating substructures. This can now be done in minutes by a laboratory software program.

The number of dental laboratories acquiring some sort of computerized system that aids in the fabrication of a restoration increases daily. These CAD/CAM systems allow dental laboratories greater efficiency, production, and profitability. Even dental materials are gearing toward CAD/CAM production. Before CAD/CAM, did we have zirconia single copings and frameworks? The introduction of the lithium disilicate LT block (Ivoclar Vivadent, Inc, Amherst, NY) has allowed chairside and dental laboratory milling of a crown to full contour and insertion using conventional cementation. In the near future, fabrication of fixed partial dentures will also be constructed using the same methodology.

CAD/CAM is definitely here to stay and will continue to have a tremendous impact on the way dentistry is practiced.

Dr. McLaren
The answer is a resounding “Yes.” I think the presence of this technology is going to increase as costs come down for materials and accuracy improves. I believe that in the very near future, maybe 3 to 5 years, 10 years on the outside, 80% to 90% of restorations will be done with some form of CAD/CAM; it’s about 20% right now. One of the most fascinating things I’ve seen on the horizon is scanning technology that uses non-ionizing radiation that can see through soft tissue. So the future is looking like you’ll be able to prepare teeth without having to pack cord or do any conventional tissue displacement, and this imaging technology would be able to see through the soft tissue to the hard tissue and image the preparations.

In that process, I don’t necessarily see the ceramist completely disappearing. I do see the job of the model-maker or the person waxing or making copings completely disappearing to technology, but I see for at least 5 or 10 years, maybe 20 years, that the ceramist will still have a job, because as good as these machines are getting, they’re not going to replace the anterior ceramist. What the machine will do looks okay for posterior restorations, inlays, onlays, crowns...I think virtually 100% of those will be done by CAD/CAM in the near future, but we’ll still use the ceramist to touch up, maybe add a little bit of porcelain, create a little bit of contour. Essentially they’ll be a finisher, a sculptor after they start with a base.

Everybody’s talking about the cost. You should buy a technology regardless of the cost if you can generate new business that will pay for the purchase in 1 year and if the purchase would stave off a concomitant loss of business. So if it’s a $100,000 machine that’s preventing a $100,000 loss of business or making $100,000 in a year, buy it. One year is the window because in 3 years there will be a new model and you have to feel that you’ve made money on it or you won’t buy the new one.

The last thing is that I caution dentists who want to get into these chairside systems if they’re really, really busy: There is a learning curve to these, and if you don’t have the time or spend the time to learn how to use it, you’ll end up having a $100,000 coat rack.

About the Authors

Allan G. Farman, BDS, PhD, MBA, DSc
Professor of Radiology and Imaging Sciences
Department of Surgical and Hospital Dentistry
University of Louisville,
Louisville, Kentucky


Gregg Helvey, DDS
Adjunct Associate Professor
Virginia Commonwealth University
School of Dentistry
Richmond, Virginia

Private Practice
Middleburg, Virginia


Edward A. McLaren, DDS
Director
Center for Esthetic Dentistry

Founder and Director
UCLA Master Dental Ceramist Program

Adjunct Associate Professor
UCLA School of Dentistry
Los Angeles, California

Private Practice limited to Prosthodontics and Esthetic Dentistry
Los Angeles, California