Innovative at Heart: a Story of 3D Printing and Dental Technology

Image showing a silicone gingiva mask – 3D printed with ACEO®’s drop-on-demand technology

Silicone gingiva mask – 3D printed with ACEO®’s drop-on-demand technology (Photo: Josef Schweiger, Poliklinik für Zahnärztliche Prothetik – Klinikum der Universität München)

In a recent project, the dental laboratory of the Polyclinic for Dental Prosthetics in Munich chose ACEO® to further advance the use of additively manufactured gingiva masks. Josef Schweiger, M.Sc., is at the helm of the dental laboratory and gives us insights into an industry that started using 3D printing technologies as early as in the 1980s.

ACEO®: Mr. Schweiger, thank you for taking the time to speak with us. You are heading the dental laboratory of the Polyclinic for Dental Prosthetics, which is part of the world-renowned Ludwig-Maximilian-University (LMU). What is your professional background?

Josef Schweiger: I am a certified dental technician. After my apprenticeship in 1988 I first worked for industrial dental laboratories. Through my job I knew the Polyclinic for Dental Prosthetics very well. There was a vacancy for head of the dental laboratory in 1999, and I immediately applied for it. 20 years later I am still here with the same motivation. The LMU made the claim on themselves to be among the first in innovation – there is no better place for me to act out my curiosity for new technologies on an everyday basis.

How did you learn about 3D printing technologies?

3D printing has been around in odontology for a long time. We started with digitalization in dental technology 20 years ago. Back then the standard workflow for the preparation of crowns was to make a tooth imprint, send it to the lab where it was poured with gypsum.

The dental technicians would then 3D scan the gypsum positive of the imprint, which helped them create the CAD construction. Once created, the data were transferred to a CNC milling machine or metal 3D printers, where the customized crown was produced.

The only thing that has changed in this process over time is that intraoral 3D scanners were rarely used by dentists before the turn of the century. This process makes the tooth imprint and the gypsum part obsolete.

When did you first use 3D printers?

In 1999 I discovered a 3D printing company in Munich that cooperated with a local car manufacturer. I worked with them on different occasions and have to admit I totally underestimated the technology. It is so simple – all you need is x/y/z coordinates to conduct the process. Today, they are among the global market leaders.

What has changed since the beginnings of 3D printing?

Due to a number of patents it was not possible to go to market with certain competing technologies. I guess this slowed down the evolution from the start. The last of these patents expired around ten years ago. This was the starting signal for many other players. All in all I would say not much has really changed in the past 15 years – except for materials.

Why did you get in touch with ACEO®?

One Sunday morning in 2018 I came across ACEO® in an article. I learned that WACKER was behind this project and that’s what made it so interesting for me: WACKER’s knowledge and market leadership in the area of silicones is so advanced. We use WACKER silicones and know very well about the quality of the material. ACEO® uses the very same knowledge and material and adds an innovative technology to it.

You have to understand that the haptic and mechanical properties of silicones are essential for our work. ACEO® is using a highly qualitative material, cures it with UV and at the end the properties are the same: there are no plasticizers in use that would affect the haptic and mechanical behavior.

So I thought of a way to test the product and the next day I got in touch with the team. A couple of weeks later I did my first test prints in ACEO®’s Open Print Lab in Burghausen.

Did you have a particular part in mind for your first test?

Although ACEO®’s silicones have been tested for medical classification IIa, which means they can be used on skin, I wanted to start with something that can be used primarily in a dental lab. The perfect test for me seemed to be gingiva masks.

What are gingiva masks and what are they used for?

We use gingiva masks in the production of crowns for implants. When we get the digital or physical imprint of the patient’s oral cavity, there is one factor you cannot calculate digitally: real gingiva is flexible and extremely sensitive.
The data we have tell us how deep the implants go and where the gingiva starts and ends. But in order to create the perfect crown, we need a realistic gingiva model made of more flexible material than gypsum, a material that can be modified in its shape. These so called gingiva masks are put on the gypsum imprints and provide realistic conditions for dental technicians when they create crowns. Thus, pressure points are avoided and the number of corrections are minimized.

What are the advantages of using ACEO® for gingiva masks?

ACEO® has several USPs in this matter. One is the perfect material: Their silicones have properties similar to gingiva. They are impermeable and comply with medical classification IIa. They come in different shores and colors so the 3D printed parts look and feel realistic.

Another USP is their technology. Until today there is no subtractive manufacturing technology that can process silicone. When getting data from a 3D intraoral scanner, the only way to create physical models is to mill or print them. ACEO® offers the perfect solution to manufacture an artificial gingiva. There is no real alternative.
Last but not least it is the team that makes the difference. When we face challenges with structure or layer thickness, they try to find a solution.

Are you planning to another project with ACEO®

We also work closely with the Technical University (TU) in Munich – especially with Medical Technology and Engineering. Together with ACEO® we had some discussions for joint projects but it is too early to be specific.

Let me put it this way: With medical classification IIa, ACEO®’s potential is huge. I can think of many ways dental technology can benefit from 3D printed silicones in the near future.

Image showing a CAD construction of dental implants

CAD construction of dental implants (Photo: Josef Schweiger, Poliklinik für Zahnärztliche Prothetik – Klinikum der Universität München)

Image showing segmented teeth and gingiva

By using model builder software, teeth and gingiva can be segmented.(Photo: Josef Schweiger, Poliklinik für Zahnärztliche Prothetik – Klinikum der Universität München)


Image showing a gingiva mask on top of a 3D-printed tooth-model

Gingiva mask on top of a 3D-printed tooth-model based on data from a 3D intraoral scanning device (Photo: Josef Schweiger, Poliklinik für Zahnärztliche Prothetik – Klinikum der Universität München)