An ambitious project for the dental schools of the future: New 3D models based on real clinical cases

That’s why it’s important to ensure that all the technical steps cause as little stress as possible. There's a lot at stake here. Each cubic millimeter of hard tissue filed off will never grow back. You can only do it once. You've got to value that hard tissue and go in prepared so that you don't take too much off. Practicing on authentic models allows for a smoother and more comfortable transition to working with real patients. An example from my own life is that my first apicoectomy was on a real person. This involved opening up the tooth from the outside and drilling into the root before removing part of it. I might have felt happier if I'd had the chance to practice this procedure on a realistic model first!

You've got to remember that – unlike medicine – studying dentistry means immediate qualification at the end. You could theoretically set up your own dental practice the day after you sit your final exams.

You couldn't have made your models without the advances in 3D printing in recent years, right?

Correct. These structures can only really be made in this way. It would be practically impossible to achieve them using subtractive, milling, or grinding techniques. The great thing about 3D printing is that you can also print using different materials. And it's thanks to Alexey Unkovskiy on our team that we have been able to produce our models in this way at all. He is our 3D printing specialist and knows his stuff. He also wrote his habilitation project on epitheses, i.e. aesthetic prostheses used in facial reconstruction that can be individually manufactured with 3D printing. It's an extremely interesting subject which very few academics are working on.

Who else is part of the team aside from Dr Unkovskiy?

We have Jeremias Hey, who brought plenty of teaching expertise to the project in addition to my own. He also has prior experience of working on a chatbot project which has been beneficial, of course. We first met fourteen years ago during our Master of Medical Education. Unfortunately, he will miss the group photo because he is now Professor of Prosthodontics at University Medicine Halle. And then we have Manja von Stein-Lausnitz, our course coordinator. She has taken on the entire coordination of the project and contributes her own teaching experience too.

What is the current project status, which phase are you in right now? Have you used the preliminary models in teaching?

One clinical case report has been fully prepared. The model depicting this case will now be tested by a small cohort of seven students who are in their fifth semester. This means they are all studying according to the old licensing regulations. But they will be the very first people to test one of the new models. In the next stage, we will get another cohort of twenty students in their seventh semester to work with the model. Unlike the first smaller cohort, the second cohort will already have experience in working with real patients. So we're right in the middle of the testing phase! The plan is to then perform a crossover evaluation of the whole project. Students will first be given the new model to practice on. They will then be split into two groups, with one group continuing with the new model while the other is given the classic typodont. We will then establish whether there is a measurable effect for the students who switch back to the old model, i.e. whether the differences between the models have a significant impact on learning outcomes and thus influence the quality of dental training.

What are your plans for the future?

We want to put loads of patient clones out into the world. It's time to leave the standard model behind! Where feasible, the models we have developed should be used in practical dentistry exams. One day they might even become the new standard across Germany. We also envisage creating an open access digital library of all the clinical case reports associated with our models. Ideally, every university could then work with them, on the condition that they also provide at least one case report or the raw data (a patient's medical history and CT scans) for a case in return. This would be the next stage in expanding the project, and we still need to agree on a funding model. But first we want to carry out the evaluation phase with both cohorts so that we can apply the results going forward. This year we submitted a paper to the European Journal of Dental Education. It's still under review, but once published we will have evidence of our initial work, and this will come in useful when applying for the funding we need to scale the project. We have no shortage of clinical cases, but we do lack the resources to prepare them. The process of putting together a three-dimensional data set costs time and money! The Max Rubner Award has enabled us to expand our expertise in a hands-on way and demonstrate that we are a strong partner for subsequent funding. It's looking promising in terms of staff too. One of our former student assistants will return after their exams to work as a researcher on the team, so there's good continuity there. We also have a couple of dissertations in progress within the project.
In future, I'd like our imaging of the models to replicate the real patient scenario perfectly with the opacity of the bone and the hard dental tissue matching the original X-ray. That would be a real leap forward. As a team, we are also interested in sustainability. It's definitely an important issue for the future of dentistry as a whole, though it's only been more widely discussed in the last year or two.

Can you tell us more about this?

Of course. The materials used in 3D printing applications like ours largely consist of plastic, unfortunately. We're on the lookout for more sustainable alternatives, and we already use PLA in our implant surgical guides; this is a biodegradable plastic derived from lactic acid. But the sector is not there yet as a whole. Overall, we're just happy to be able to print precise models. Sustainability is still a secondary issue for now.

But another aspect which can be understood in terms of sustainability is time efficiency. We want to keep in-person appointments with patients to a minimum. Time is a resource which should be used carefully. We shouldn't just assume that the patient needs to come to us all the time. Our chatbot helps to prepare our students for the increased use of telemedicine in future. We should always think about whether the patient needs to come in, or whether they could discuss some aspects online in advance.

Looking back, what was it that inspired you to study dentistry?

That's a great question. My father was actually a dentist too. I even spent my first two years with him as a dentist at his practice in Upper Bavaria. But it wasn't quite what I wanted. My brother also went into dentistry and is now an oral surgeon with his own practice. I feel that there are only really two reasons to go into this job. You've either got a dentist in your family already, or you have had lots of problems with your own teeth and want to help others. No kid in kindergarten says they want to be a dentist!

Why didn't you want to open your own practice like your brother? What motivated you to work at the university?

I really like the combination of teaching, research, and patient care that you find at the university. I absolutely love treating patients and really like people. That's the basis for this job, I think. At the same time, it's amazing to be able to pass the knowledge I've gained in a clinical setting onto my students and the researchers in my team.

What else do you like about your work?

The feedback is fantastic, especially the gratitude that comes as soon as you have freed a patient from pain or given them a new set of teeth. In most other areas of medicine, you don't get this feedback so quickly. It’s also nice that my everyday work rarely involves questions of life and death. I've been in this field for over twenty years now and still delight in the things that go well, and that includes aesthetics. Dentistry is a near-perfect combination of craftsmanship and medicine.

And finally, why should young people interested in dentistry apply to study at the Charité?

Well, firstly they get to learn with the models we're developing! Plus, they would be very well looked after at the Charité. We have an exceptional team of lecturers with a diverse range of ideas. Studying here is an attractive option. Every competence found in dentistry is covered at the Charité – you can go into whichever specialism you like.

Marike de Vries & Dr. Nina Schmidt
June/July 2023