A 3D-printed Tooth That Can Do Everything

Whether caries removal, root canal treatment or crown preparation - students can really get to grips with the teeth from the 3D printer. Current scientific studies confirm the high learning effect, the acceptance among students and the didactic benefits of the universal practice tooth.

Dentistry students at the University of Würzburg need an average of 300 practice teeth to practise the various techniques and treatments and to be able to treat patients safely, efficiently and successfully later on.

Students have to acquire these artificial practice teeth themselves and also collect real teeth in dental practices and from surgeons. However, this brings with it numerous ethical, hygienic and legal challenges. For example, authorisation for further use is required through extensive documentation, and there is a low risk of infection from these real teeth.

In addition, these teeth are usually heavily pre-treated or damaged, meaning that they are not always suitable for training purposes and, above all, do not offer standardised learning conditions. Commercially produced practice material is also not an ideal alternative, as it often does not correspond to real conditions.

3D-printed Decayed Tooth Based on a Three-dimensional X-ray Image

This is why the Polyclinic for Dental Prosthetics at the University Hospital Würzburg (UKW) has been producing its own practice teeth since 2020. "This not only allows us to save costs, but also to combine as much learning content as possible in a realistic tooth and provide students with more intensive training," says Dr Christian Höhne. The senior physician is responsible for preclinical teaching in the department under the direction of Professor Marc Schmitter, Medical Director of the Polyclinic.

Höhne produced the first 3D-printed tooth back in 2019, based on a three-dimensional X-ray image of a decayed tooth. In order to realistically depict the layers of the tooth, he used different materials with varying degrees of hardness.

This gave the students tactile feedback when drilling through the corresponding areas, similar to a natural tooth. This allowed them to practise when to stop or work more carefully. The study published in the Journal of Dental Education showed that 3D-printed teeth are a promising alternative to classic model teeth.

Six years and several publications later, the Dental Prosthetics team presents a 3D-printed tooth that is suitable for all major dental procedures - from caries removal and filling to root canal treatment, crown preparation, post drilling and X-ray examination - until the tooth has to be extracted in reality. In December 2023, the team was awarded the Albert Kölliker Teaching Prize by the University of Würzburg's Faculty of Medicine for its outstanding teaching methods.

Additively Manufactured Practice Tooth for Root Canal Treatments

The analyses of the various treatment steps were divided among some of the more than twelve doctoral students involved in this teaching project, which Christian Höhne is currently supervising together with Marc Schmitter.

As part of her doctoral thesis, assistant doctor Isabella Di Lorenzo, for example, worked on the root canal treatment of this universal tooth in collaboration with the Polyclinic for Tooth Preservation and Periodontology under the direction of Professor Gabriel Krastl. After printing, she took care of further processing, such as washing the teeth, and tested the tooth in a preclinical course with 38 dental students. Isabella Di Lorenzo has just published the results as first author in the scientific journal Scientific Reports.

"The students rated the 3D-printed tooth as a significantly better practice option than the usual transparent acrylic blocks that are often used for practising root canal treatments, and almost on a par with natural teeth, especially in terms of realism, handling and learning value," summarises Isabella Di Lorenzo. "The printed tooth is not only realistic and cost-effective, but also fair. With the new practice tooth, we have created identical examination and learning conditions for all students."

Senior consultant Dr Michael del Hougne, course leader in the field of clinical teaching, is also enthusiastic about the new practice tooth. "Our students can even use the model to practise measuring the electrical length of the root canal very realistically. However, we had to play a little tricky to achieve the required conductivity, as the tooth is made of resin, which does not conduct electricity." The next step is to develop 3D teeth with different root canal shapes in order to simulate the clinical challenges that arise from the anatomical diversity.

Simple Application and High Learning Effect for Caries Excavation

Caries removal and treatment of the dental nerve were also optimised on the new training tooth. Former doctoral student Dr Lisanne Carnier published an extremely positive evaluation of the printed tooth in the journal BMC Medical Education in October 2024. The students rated the 3D tooth significantly better than the previous models and wanted more exercises with the new models. The application was easier and the learning effect higher.

3D Tooth for the Preparation of Adhesive Bridges

In September 2024, one month earlier, Michael del Hougne's research group published the successful test runs of a 3D-printed tooth in Scientific Reports. Forty-two students were able to practise preparing an adhesive bridge on this tooth. This tooth was developed as part of a doctoral thesis by Dr Greta Behr. It has two coloured layers that show exactly how much material needs to be removed and where. Here too, the students gave the practice tooth an average grade of "very good". They were able to visualise the exercise goal better and check their work themselves.

In Dental Prosthetics, All Disciplines Must be Mastered in Order to Crown the Tooth

"This innovation, the additive production of a training tooth that can do more or less everything and optimises teaching, has come at exactly the right time in dental prosthetics," says Marc Schmitter. The new licensing regulations for dentists mean that prosthetics only has a third of the time in teaching that it used to have. A great deal of knowledge and manual skills are required in dental prosthetics.

"Apart from orthodontics, we have to master all disciplines in order to finally place the crown on the tooth. Sometimes we even have to lengthen the tooth surgically. Added to this is the increase in knowledge regarding materials. So we have to impart more and more knowledge and skills in a very short space of time," explains Marc Schmitter. This is possible thanks to 3D printing. The low costs and easy reproducibility enable more frequent and more intensive training.

App With Augmented Reality Allows Better and Simpler Correction in the Awakening Course

Another innovation in dental teaching is an augmented reality app for the so-called wax-up course. The app helps students practise moulding teeth with wax and using wax tools. Using the app, students and teachers can view the wax-up template via the camera on their smartphone or tablet and superimpose an ideal wax-up on the wax-up plate.

This enables students to assess themselves better and learn faster. The multi-award-winning feasibility study by first author Johannes Schrenker is currently available as a preprint on the Research Square platform and will soon be published in Scientific Reports.

Evaluation of 3D-printed Temporary Dental Crowns

Patients also benefit from innovations in dental teaching. On the one hand, better trained dentists lead to better treatments. On the other hand, patients at the UKW are already being offered 3D-printed dentures - with success!

As part of his Master's thesis, Michael del Hougne analysed the longevity of a total of 98 3D-printed temporary dental crowns in a cohort study with 63 patients. These are crowns that are inserted temporarily until the final restoration is made. The results published in Scientific Reports show that 98 per cent of the crowns survived the study period of 256 days on average without any major problems. The patients were very satisfied with the appearance. Their quality of life also improved significantly in connection with their oral health.

Publication

Isabella Di Lorenzo, Michael del Hougne, Gabriel Krastl, Marc Schmitter & Christian Höhne. 3D printed tooth for endodontic training in dental education. Sci Rep 15, 20185 (2025). https://doi.org/10.1038/s41598-025-06081-y