CEREC inventor comes to Sydney

The CEREC 2003 International Masters Symposium immediately preceded FDI at the Sheraton on the Park Hotel in Sydney. A key presenter at the event was Professor Werner Mörmann, the man who started it all when he created the first version of CEREC back in the early eighties.

Professor Mörmann together with Dr Marco Brandestini succeeded in inventing what many dental manufacturers worldwide are still attempting well into the new millennium.

At a time when the occasional IBM PC sat in the corner of offices filled with mainframe-driven CRT screens and the few home computers had as much as 20K of RAM, Professor Mörmann transitioned a fledgling clinical concept into what would become the world's one and only chairside CAD/CAM restoration system to date. There are now some 12,000 CEREC users worldwide and over 280 in Australia and New Zealand alone.

"Throughout the seventies, I'd been teaching amalgams and gold restorations to students and was looking for an alternative," Zurich-based Professor Mörmann explained. "I was fascinated by tooth-coloured direct restorations but the frustration was the effects of polymerisation shrinkage. I felt bonded inlays were the answer, so I decided to try and come up with a system to do it chairside and fast!

"It was clear from the outset that we needed new technology and a new material to make it work. We chose a ceramic as it is very close to human enamel in its physical properties, durability and aesthetics and it can be bonded to the tooth."

Professor Mörmann had defined the process and filed a Swiss patent by December 1980 and a European patent was lodged the following year. The process was as it is today:

• Provide a ceramic restoration at chairside;
• Restore a tooth in one appointment using an Optical 3D impression; Computer-Aided Design (CAD); and, Computer-Aided Manufacture (CAM);
• Use adhesion to reinforce the ceramic and the tooth.

"We had a lot of work to do as everything had to be made from scratch."

The first version of CEREC was built in May 1983. It consisted of a small mobile unit with a custom 3D camera and imaging, a Motorola 68000 processor, integrated form-grinding, a machining chamber, pelton wheel, water pump and tank.

"We experimented with using active triangulation 3D scanning in 1983 and proved we could do it on the bench. We then went to Silicon Valley to the Fairchild Company to get a CCD chip to register the scans. Rapid scanning was the key and we developed the camera between 1983 and 1985."

The revolutionary work done in the camera design has stood the test of time with CEREC 1, 2 and 3 using virtually the same principles with only slight improvements. The heavily patented camera and its ability to capture a digital impression in situ is CEREC's differentiating feature in the world of CAD/CAM dentistry.

"All the information is captured by one single optical impression viewed along the path of insertion with the 3D active mouth camera," he explained. "I don't know of any other 3D medical scanning device producing quantitative 3D data that is handheld."

Software development also progressed between 1983 and 1985 with the first CEREC Operating System, COS 1.0, programmed by Dr Alain Ferru. Form grinding experiments on the ceramic were conducted between 1981 and 1985. The CEREC name was devised in 1983 as a short form of CEramic REConstruction.

"On September 19, 1985, we made the first chairside inlay using CEREC 1," he said. "Several clinical studies continued to confirm the CEREC clinical concept with the best marginal adaptation and minimal wall to wall tension. Amalgam and gold were both proved to leak but with CEREC, there was no leakage.

"We had confirmed the clinical concept by 1985 and in 1986, we opened it up to the public. Dr Marco Brandestini and I had founded a company in 1985 with capital of one million Swiss Francs to develop the hardware and software in Marco's garage."

According to Professor Mörmann, the initial capital was rapidly consumed and in 1986, Siemens became involved as a new partner in the project.

The Siemens R&D team continued the development of CEREC in co-operation with Professor Mörmann and in 1994, CEREC 2 was released and was viewed as a significant breakthrough in the capabilities of the system and also introduced new materials including a glass ceramic and composite blocks. The new finger bur complimenting the existing grinding wheel also meant the system could mill crowns.

In January 2000, a significant revision of the system was released in the form of CEREC 3, which split the chairside imaging and design component from the milling system, which now had even greater versatility with two burs.

"All the restrictions with disc milling were overcome by CEREC 3," explained Professor Mörmann. "You no longer had to think of the restrictions any more."

Sirona Dental Systems, the former dental division of Siemens, has continued to invest significantly in CEREC, with the release in early 2003 of the CEREC 3D which significantly enhanced and simplified restoration design and was available as a software upgrade to existing CEREC 3 users. The release of the CEREC 3D 1100 software upgrade during the Masters Symposium added further functionality to the system that now creates inlays, onlays, crowns, veneers and in the laboratory version, multi-unit bridges and crown copings.

Professor Mörmann now resides at the Division of Computer Restorations Center for Oral and Dental Medicine, University of Zurich, Switzerland, where he works with a group of eight young post graduate dentists doing their thesis on CEREC; teaches undergraduate students; conducts laboratory and clinical studies; and overall concentrates on using cutting edge technology to solve everyday dental problems.

"I am very proud of the evolution of CEREC and the fact that clinical research over a 10 year period shows a 95%+ survival rate.

"Right now, dentists have to learn something about the technology to make it work. My dream is to have CEREC fully automatic - hold the camera and the machine will do the rest, leaving the dentist to concentrate on the patient and the aesthetics."