Days of Future Passed

As a rock star wannabe, I have always been thrilled to meet famous music legends.

by Paul Feurestein, DMD

For more on this topic, go to www.dentaleconomics.com and search using the following key words: 3M ESPE, CEREC, Dr. François Duret, Sirona, impressions, restorations, prototype.

As a rock star wannabe, I have always been thrilled to meet famous music legends. If we ever cross paths, ask me about meeting Janis, Jimi, and other '60s notables, as well as a couple of recent encounters with Jim (Roger) McGuinn and Peter Yarrow. My latest encounter was similar when I met and spoke with Dr. François Duret. Although not a household name in dentistry, those of us in the high tech arena know his name well. I met Dr. Duret when he gave a lecture at a symposium in May hosted by 3M ESPE (the Espertise™ 2008 Gobal Symposium). Later, I interviewed him. A little dental history will introduce you to Dr. Duret.

CEREC celebrated its 20th anniversary in March 2006. The first CEREC chairside treatment took place Sept. 19, 1985, at the University of Zurich Dental School. This was the result of five years of work by Dr. Werner Mörmann and Marco Brandestini. In a 2006 article in the JADA, Dr. Mörmann states: "Early in 1980, I anticipated the attraction of restoring posterior teeth with tooth-colored materials ... we could not use direct composite fillings because of polymerization shrinkage, the resulting formation of a marginal gap, and lack of abrasion resistance." The CEREC prototype took form as a product in 1986 with the Siemens Corporation, which ultimately became Sirona. So what does this have to do with Dr. Duret?

Here are excerpts from his lecture and talks with me: The day after Christmas in 1970 (10 years before Mormanan's vision), a 22-year-old dental student named François Duret had a vision. He thought that impressions and restorations could be done with some physics, optics, and computers. Keep in mind that Apple came about in 1976 and the IBM PC in 1981. Duret had an uncle in the technology business who led him to the literature that described the foundation of this information.

At Duret's dental school, students needed to write a thesis to finish a degree. So in June 1972, he wrote about his concept. Published in June 1973, the document was 288 pages in length with 308 references. At graduation, Dr. Duret asked for a position at the dental school but the response was, "This man is crazy if he wants to work at the university. He had better close his mouth and drop this foolish idea."

Dr. Duret did get the job. With private and family financing, he set up shop in his garage — located outside the university. Here he began creating the prototype.

His basic idea was to use video cameras with four fiber-optic bundles. Two fed cameras that showed a tooth's buccal and lingual at the same time. The other two were lasers. The information was sent electronically via what was to become the Internet. (To clarify Internet history here, early versions were available in the '60s with the culmination of Arpanet in 1969.)

The information was sent to a large lab, which had sophisticated CAD/CAM machines that could design and build restorations. The first prototype was shown in Paris in 1983. Then, in front of 800 dentists in 1985 in Paris, a crown was prepared, impressed, and fabricated on a patient (his wife). This video camera was not only able to capture the prep image, but also a dynamic view of occlusion. In 1987, Dr. Duret took his equipment to the Chicago Midwinter Meeting and did a live demonstration. He then went to Berlin in 1989 and demonstrated the manufacture of bridges.

Siemens also was working on a system and looked at what Dr. Duret was doing. Since his paradigm involved sending the information to a lab, and the Mörmann/Brandestini concept was in-office, the latter prevailed and a dejected Dr. Duret all but left the scene. Later he went to USC and GC Corporation where he helped develop the GN1 CAD system, and was involved in the manufacturing of more than 15,000 restorations.

When I asked Dr. Duret for his vision of the future, he said that digital impressions will be dynamic with video and also will capture occlusal movements. He sees a coordination between the dentist and a lab with a milling machine in the office that the lab controls via the Internet. The in-office machine will make temps and simple restorations under the dentist's control, but more sophisticated restorations will be machined in the office under the lab's control.

Dr. Duret's presentation is available at www.3MESPE.com/symposium. My interview is on the Dental Economics® site at www.dentaleconomics.com. It was a great thrill for me and others to meet this dental legend.

Dr. Paul Feuerstein installed one of dentistry's first computers in 1978. For more than 20 years, he has taught technology courses. A mainstay at technology sessions, he is an ADA seminar series speaker. A general practitioner in North Billerica, Mass., since 1973, Dr. Feuerstein maintains a Web site (www.computersindentistry.com) and can be reached by e-mail at drpaul@toothfairy.com.

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