An Interview with Dr. François Duret

“Health care is a science and invention is an art which, as in a painting, blue and mauve periods which mark the evolution of our research and thoughts.” —Professor Francois Duret

After years of research and development, the clinical benefits of optical impressions now exceed those of conventional impression techniques and the cost of this digital device will soon no longer be a limiting factor, explains Dr. François Duret. Duret, known as the “father of CAD/CAM technology,” has spent the past 40 years pursuing his passion—developing new technologies that will bring the practitioner substantial assistance to the clinical procedure. We sat down with Dr. Duret at the Imagina Dental show, held in Monaco in February 2013. Devoted to CAD/CAM digital dentistry, Imagina Dental features the world’s top dental professionals sharing the latest innovations in 3D and CAD/CAM technology.

Inside Dental Technology (IDT): Why devote an event such as Imagina Dental exclusively to new technologies in dentistry?

Dr. François Duret (FD): It is essential for practitioners, who have been practicing dentistry for many years, to focus on these new methods of diagnosis and treatment, to see if they are technically proven. For young practitioners leaving the university, this conference offers the opportunity to enhance their knowledge and immediately adapt to technologies that match their computer skills. Adapting to newer technologies is much easier for them since they are accustomed from a very early age to mixing high-level processes.

IDT: Cone beam CT scanning, the dental laser and optical impressioning are particularly highlighted during this conference. What are the major advances in these three areas?

FD: For the cone beam is its popularization and authorization. This complex system and its radiological purity and image has become an essential, if not indispensable, tool for implant treatment. Its use is simple and the results are far superior to other radiological techniques. In addition, cone beam scanning delivers a reasonable dose of radiation in comparison to the vast amounts of information delivered.

The laser is a relatively old technology that makes regular reappearances. Launched in France by Professor J. Melcer in the 1970s, it was originally used for soft tissue intervention. At the beginning, the cost versus return on investment was questionable but this obstacle to adoption then decreased. However, only a certain elite in the profession felt comfortable using it. Then, in the second half of the mid-1990s, the marketing of lasers for hard tissue intervention led to a renewed interest. But interest declined again as the expected result was not achieved. The technique is quite complicated and the process too slow. The recent release of small, inexpensive lasers has again revived the market, opening the door in general practice for small surgeries. We went from equipment costing between 30,000 euros and 50,000 euros to a new generation of products now available for only 3,000 euros.

IDT: In terms of market penetration, when do you believe the market will be ready for the conversion from analog diagnosis and treatment options to digital?

FD: We will definitely see an increase in the adoption footprint of digital technologies with the next generation of dentists. They have grown up playing video games. It is natural to them to observe and manipulate 3D objects on the computer screen. Today’s optical impression is more accurate than in the past and helps the general practitioner to achieve a superior impression. In case of missing information or process error, it is not necessary to repeat the impression and risk missing critical details if blood is present or if the impression material has not hardened properly. Digital technologies can clear the error and the dentist can rescan this area only. Yet another advantage is the possibility for the dentist to see his work appear in real time on the screen, and thus control the progressively entering information.

IDT: What do you say to the practitioner who is reluctant to equip because of the cost argument? Is the cost limitation still valid?

FD: No, the cost will soon be a limited argument. A revolution will take place in three to four months. Today, the market is shared between very large players such as 3M ESPE, Sirona, Straumann or 3Shape, which will compete and propose new forms of purchase. Prices will, and have, already declined.

IDT: What do you recommend to the dentist who decides to equip?

FD: Try all the different brands just as if you were buying a new car. Participate in pre-training sessions offered by the different dental societies. Do not hesitate to contact the various manufacturers to try out the equipment. I also recommend professionals use the equipment in the daily routine of the office for a at least a fortnight, with serious assistance and guidance. This allows you to see if the device fits well into the daily practice. I also advise them to make a calculation of profitability. Practitioners who hesitate are often those who have not done this calculation. Be that as it may, the optical impression system will eventually become inescapable as more laboratories equip their businesses with CAD/CAM technology.

IDT: Does the choice of a device involve a dependency for a brand?

Yes, and I think this will be the case for some years. Just as when you buy a car, you are purchasing a brand that you believe will provide the best precision drivability and durability as well as support and service. This is why the choice of model is important.

IDT: What will become of the profession of dental technician? Do you think it could disappear?

FD: Absolutely not. The two businesses are inseparable. The theory that prosthetics would disappear was the argument of the critics of chairside CAD/CAM. But to think that the dental technician could be replaced by a machine is a spirit that is narrow and false.

Some manufacturers of these devices tried to build their reputation on the fact that dentists can carry out work in the office without calling a technician. However, this work is restricted to prosthetics that are simple to make. Even if dentists can also make small ceramic bridges in-house, I sincerely think that the implementation is much less successful than laboratory. In reality, the dentist and dental technician each retain their specific tasks. The practitioner will use the optical impression as he used the tray. He will give the laboratory the scan and dental technicians will carry out the rest of the work. The real question for the future is what will be used as the production tool. Will it be a device using subtractive processes (milling) or additive processes (fusion or laser stereolithography). And where? In the office or lab? Undoubtedly in both of these places, but in all cases, the practitioner will follow the guidelines and information from the laboratory. In this dual process, the prosthesis can be performed almost in real time, while the patient is still in the chair!

IDT: This implies still a disruption of the profession of dental technician.

FD: Yes, but it will always be about the prosthesis. The new software does not require a computer professional but rather a computer operator that is a good technician.

IDT: How do you imagine the dental office of tomorrow?

FD: The issue is very complex. In very broad terms, I think the manual aspects of dentistry will dominate. However in the dental office of the future, the dentist will be surrounded by highly sophisticated machinery that is very important for the realization of the clinical act, but ultimately it is he who will operate. This assistance will be "virtualized" and imaged as a guide. The practitioner will enjoy augmented reality. Such augmented reality already exists in our cars where a driver receives information indicating if there is ice on the road and where it is located. In the dental office there will be systems around the dental chair that tell the practitioner if the process being carried out is correct. Different methods exist. They have been tested, especially in Japan.

This information will be real-time data and will be documented. The whole chain will act in an almost virtual reality. I said this 40 years ago but few believed me. Today, it is reality. I confess that it makes me happy because I could have been wrong.

The use of plaster to create models seems completely obsolete and outdated today. Plaster considerably limits the possibilities when you could be virtually cutting and sectioning models and identifying areas of insertion. At the same time, the model does not move, does not break, and is durable over time. A broken crown can reproduced by any dentist in the world—if he is digitally equipped. Thirty years ago, in my laboratory, we thought laser cards. Today, they are smart cards. Each patient will have his complete oral information and history stored on a smart card. It will be recognized at the door of the dental office and the file automatically activated.

IDT: You said at the ADF this was your last dental meeting yet for the second time you are honorary president of Imagina Dental. It's hard to believe you when you announce your retirement.

FD: It is the culmination of a busy professional life that I really have loved. I thank all my colleagues who have supported me. I often think about this or that face. This is the start of a new life that I will devote to writing books and coaching a small research team of engineers. I want to enter into a further clinical basic research.

IDT: In what areas?

Thus far, I have invented in a variety of fields. I’m even inventing when I write a poem I don’t need to have a specific focus and can let my thoughts wander. I am a free man. I could very well create an invention for the orthodontics field tomorrow if an idea came to mind that I liked. That said, the fundamental focus of my research will be in the digital arena and perception of the world at large. I have a lot of interest in the quantum aspect of the image. It is a world unexplored and promising. I also could write a series of books on the optical impression, modeling and machining method. I documented testing over the past 30 years without ever releasing the results, and could write a basic treaty in the field of dental CAD/CAM, which holds great interest for me.

Credit: Original article written by Anne-Chantal de Divonne for Clinic, journal of dentistry – a publication of Wolters Kluwer France – © Clinic, Éditions CdP 2013.