Development of a Teaching Tool in Dental Practical Training Using 3D Dental Printing

Introduction: Simulation plays a key role in enhancing student learning. Its use in practical work facilitates understanding and guides students through the various procedures required. The aim of this study is to highlight the impact of simulation on student learning by simulating the final result of the work required using 3D printing.

Methodology: To achieve our goal, the staff of the fixed prosthetics department sculpted wax models simulating the final result of each procedure requested in the program. Next, an optical impression of the various devices was taken using an intra-oral scanner. The acquired data were sent in a standard triangulation language (STL) file to the printer, and a 3D print was made using a specific resin.

Discussion and Conclusion: The 3D-printed pedagogical models were integrated in dental teaching. This simulation enabled students to visualize the final, full-scale result of each required procedure. It improved the transmission of knowledge, making it easier for students to learn. A study to assess students’ perceptions needs to be carried out.

Introduction

The practical work carried out for dental prosthesis students is designed to prepare the student for his mission as a prosthetist and to hone his manual dexterity. In the first year of prosthetic laboratory technology, students are required to cast impressions to obtain a model on which they will produce several prosthetic devices according to the recommendations provided. The wax devices sculpted are transformed into metal using the lost-wax technique).

To guide the student, digital resources are made available, such as pedagogical models and demonstration videos explaining the different protocols to be followed to reach each stage. Other teaching methods can also be used, such as simulation, which has become increasingly important in recent years. According to the Larousse dictionary, simulation is the representation of a physical, industrial, biological, economic or military process by means of a hardware model whose parameters and variables are as close as possible to the system under study [1]. It is an effective learning strategy to guide novices in their training [2], [3].

The contribution of simulation to the teaching of dentistry students is particularly marked, given the highly technical and practical nature of this discipline. Simulation offers multiple advantages that can significantly improve the learning and preparation of future prosthetists [4], [5].

Actually, higher education institutions use increasingly simulation in conjunction with digital technologies to enhance student learning and make learning more active and attractive [6], [7]. One example is the Faculty of Dentistry in Casablanca, which simulates the teaching assignments required of students using digital techniques. The practical guide to the use of digital technologies to support student learning, drawn up by the What Works Clearinghouse (WWC) in collaboration with a group of experts, highlights promising learning methods for students [8].

The aim of our work is to produce various pedagogical models simulating the curriculum taught in dental laboratory technology studies, using digital technology.

Methodology

To cover the taught program, a model with resin teeth was prepared containing the different types of coronal and coronal-radicular preparations (Fig. 1).

Fig. 1. Primary model containing the various preparations.

Once the preparations had been validated, the model was cast using the pindexation technique, and the various prosthetic appliances were sculpted in wax in compliance with the various criteria studied:

• Preparation for inlay-core on 24

• Preparation for inlay-core on 13

• Preparation for keyed inlay-core on 26

• Preparation on 17 for making a temporary crown by indirect self-moulding

It should be noted that this model is available for students to assist them in sculpting their prosthetic devices (Fig. 2).

Fig. 2. Working model containing the various wax models of the 24, 13, 26 and 17.

Next, an optical impression was taken. Using the Medit I500 intraoral scanner, the primary model and sculpted wax models were scanned (Fig. 2). The acquired data was sent as a standard triangulation language (STL) file to the ASIGA printer (Fig. 3).

Fig. 3. Optical impression of the primary model using the Medit I500.

3D Model Printing

To print the primary model in 3D resin, we configured the STL file to suit the ASIGA printer (Fig. 4). After configuration, the file was sent to the printer with the required recommendations, and the ASIGA Denta MODEL resin was used. (Figs. 5 and 6).

Fig. 4. STL file of maxillary model scanner.

Fig. 5. The model currently being printed.

Fig. 6. 3D printed working model.

Production of Metal Prosthetic Devices

A 3D-printed crown in burnout resin, using ASIGA DENTAL CAST resin, was produced from the burnout model of a crown cast on 24, the inlay core on 13 and the keyed inlay core on 26 (Fig. 7). A final validation of the burn-out part was carried out taking into consideration the anatomy, the prosthetic space and the occlusion with the antagonist. The calcinable prosthetic part was transformed into a metal prosthetic part after the metal had been poured into a cylinder (Fig. 8).

Fig. 7. Working model containing the calcinable model of the crown cast on 24, core inlay cast on 13 and 26.

Fig. 8. Working model containing the differents prosthetic metal devices.

Production of the Provisional Crown on 17

Following the same protocol, the provisional sculpted in wax and scanned in 3D was configured and sent to the printer to be printed using ASIGA TRY resin. The anatomy, the prosthetic space required for the future crown and the occlusion with its antagonist were validated (Fig. 9A).

Fig. 9. (A) Working model containing the burn-out model of the crown on 17 and (B) working model containing the provisional crown on 17.

A second crown, a mock-up of a crown on 17, was printed using DENTAL CAST resin to simulate the final result and support the student’s sculpture. The shape and dimensions are identical to the burn-out model already produced (Fig. 9B).

Models containing all metal and burnable resin prosthetic parts are available to students in the Dental Prosthetic Laboratory Technology Building (Figs. 10, 11).

Fig. 10. Final model with burn-out resin models.

Fig. 11. Final model simulating the final prosthetic devices.

Discussion

As in other healthcare fields, simulation is an integral part of dentistry training. The main objective of simulation is to provide a propitious environment, close to the reality, in which to learn the knowledge and technical skills that will be required in the real world [1]–[7].

The aim of our work was to simulate the final result of each stage of the program taught to prosthetists in the fixed prosthetics Department. To achieve this, we used digital technology and more specifically 3D printing.

3D printing is a manufacturing technique known as additive manufacturing because it proceeds by adding material. The starting point is a computer file that digitally represents the object in 3 dimensions, cut into slices. This information is sent to the 3D printer, which builds the part by adding successive layers. The finer the layers, the greater the precision and definition of the object [4]–[9]. The performance of this technology in terms of precision and traceability is undeniable, especially when compared with traditional techniques [7], [8].

3D printing of prosthetic devices has proved its effectiveness in guiding novices through the technical gestures required. According to the class of 2023/2024, pedagogical models recently integrated into prosthetist training have improved message transmission, facilitating learning. According to several studies, visualizing the final result clearly improves communication with students [10], [11].

To conclude, recent data on the benefits of simulation and 3D printing are motivating the integration of this pedagogical model as a complement to traditional teaching in the training of future dental technicians. We must not forget that the financial cost of simulation, which includes the cost of equipment and instructors, may seem too high for academic institutions. But these technological advances, which aim to improve realism, should not overshadow the objectives of simulation, which remain learning and performance, not the material reproduction of clinical situations [3], [12]–[15].

Conclusion

To support students in the various gestures required in our program, we proposed simulating the program, we proposed simulating the program using 3D printing. The pedagogical models have been integrated into the learning process of students in the dental prosthetics program and have improved the transmission of technical skills. An assessment of the students’ perception is envisaged.