Reasons why we are still pressing in the digital age
Robert Arvai runs a dental laboratory in Chur, Switzerland, which specializes in creating functional and esthetic metal-free dental restorations. At IDS 2019, he won the one-of-a-kind “golden” Programat EP5010 in a guessing competition. He spoke to Robert Grünenfelder (Ivoclar Vivadent) about dental laboratory technology in general and the pressing of ceramics in particular.
When did you decide to open your own dental laboratory?
Robert Arvai: After my training, I worked in various fields. One of my jobs was in quality assurance in the dental industry. At some stage, I had the opportunity to move to the US, where I worked as a departmental manager in a dental laboratory for three years. Then I was offered the possibility of establishing a new laboratory in Chur. My wife and I decided to leave the US in 2011 and we returned to Switzerland. I chose to be my own boss and I have not regretted this decision one bit.
What kind of services does your laboratory offer dentists?
Robert Arvai: We are a full-service laboratory and offer all types of dental restorations. We specialize in fabricating highly esthetic ceramic anterior restorations as well as composite veneers on various framework materials. Our work is dedicated to providing metal-free solutions, using e.g. zirconia or lithium disilicate. We generally use the veneer or press technique. We craft monolithic restorations only in exceptional cases.
You won a Programat EP5010 at IDS 2019. How satisfied are you with this furnace?
Robert Arvai: We have loved the furnace right from the start. The pressed results exactly correspond to our expectations. The flow of the ceramic materials is optimal and the pressed restorations show exceptional accuracy of fit. The furnace is easy to operate and control, so that all of our technicians can work with it.
What do you think of the integrated thermal imaging camera for the contact-free measurement of the temperature of the workpiece? Are you familiar with this feature?
Robert Arvai: We have many years of experience working with the Programat press furnaces from Ivoclar Vivadent. Nevertheless, we did not have the latest model – the Programat EP5010. As a result, we were absolutely thrilled to have won it. I was unfamiliar with the press ring recognition feature. However, I did know the Infrared Technology, which monitors the distribution of heat within the machine, from my previous Ivoclar Vivadent press furnace.
Have you tried out the FPF mode (Fully automatic Press Function)? If so, what do you think of the results?
Robert Arvai: We have only used the Fully automatic Press Function on one occasion and we were very satisfied with the results. Nonetheless, dental technicians tend to be quite sceptical about allowing a machine to do all the work. They would prefer to be in control of everything themselves … *laughs* … It is a bit of a dilemma because the Fully automatic Press Function works very well. We should probably think about taking advantage of it more often.
What are the strengths of the press technique in your opinion?
Robert Arvai: The strengths of the press technique are fairly obvious. In my experience, a pressed lithium disilicate restoration is considerably stronger than, for example, a milled framework which has to be subsequently crystallized. Furthermore, the press technique allows me, the dental technician, to control the accuracy of fit. In my opinion, the results are virtually unparalleled. Theoretically, pressed restorations are just as esthetic as their milled counterparts. However, the quality of the esthetic finishes will depend on the skill of the dental technician – irrespective of whether the restoration was pressed or milled. We use both methods, but for different indications.
In what type of cases would you prefer CAD/CAM milling over the press technique?
In this age of CAD/CAM milling and 3D printing, how does the future look for the press technique?
Robert Arvai: As so often is the case in life, not everything is black and white. All the mentioned processes have their merits. The press technique has firmly established itself in dental laboratories over the years. Pressed lithium disilicate still fulfils an essential role in the fabrication of frameworks and it is a firm favourite in our laboratory. At this stage I cannot imagine that this will ever change, despite all the publicity about milling in which the maximization of profits is often emphasized. The initial outlay and the running costs related to CAD/CAM equipment are comparatively high and have to be critically considered. If a laboratory charges too low a price for its restorations, it will not be able to recoup its investment. In my opinion the best results are achieved when a restoration is pressed in the dental laboratory and then esthetically finished by a skilled dental technician.
What would you like to see improved about the press technique?
Robert Arvai: Not much really. There is only one thing I would appreciate: a clearly defined workflow from the 3D printed workpiece to the pressed framework, without a lot of intermediary steps. An optimized workflow would help to ensure that we produce consistent, reproducible results.