Virtual reality: an effective tool for teaching root canal anatomy to undergraduate dental students - a preliminary study.

AIM: To introduce virtual reality (VR) into the endodontic curriculum for teaching root canal anatomy and to evaluate the effectiveness of this new method on third-year undergraduate students. METHODOLOGY: Extracted human teeth were digitized using a CBCT scan and converted into STL files. The corresponding files were either 3D printed or imported into a VR software program. Subsequently, forty-two third-year undergraduate dental students in preclinical training were asked to respond to a questionnaire analysing their ability to detect all the anatomic features of the replica teeth and their comprehension of the underlying root canal anatomy. The investigation was based on three different methods: two-dimensional radiography, CBCT scanning and VR simulation. Data were analysed using McNemar's and binomial test, and the level of significance was set to 0.05 (P = 0.05). RESULTS: Students reported that CBCT and VR allowed them to detect all anatomic features more than radiography (P < 0.001 - P = 0.049). Because it allowed improved comprehension of root canal anatomy, the VR simulation was considered better than CBCT scanning and radiography. Most of the students adapted well to the VR simulation. CONCLUSIONS: Dental students greatly appreciated the integration of VR simulation into the endodontic curriculum. From a didactic point of view, VR has considerable advantages over three-dimensional reconstructions and two-dimensional radiographs when teaching root canal anatomy.

A critical evaluation of the material properties and clinical suitability of in-house printed and commercial tooth replicas for endodontic training.

AIM: To assess the suitability of several 3D-printed resins for the manufacturing of tooth replicas for endodontic training in comparison with commercially available replicas by analysing the properties of the materials and comparing them with real teeth during endodontic training. METHODOLOGY: Tooth replicas were 3D-printed using four resins (NextDent Model, NextDent C&B, V-Print ee and Vero White Plus) and compared with two commercially available products (VDW and Smile Factory) as well as extracted human teeth. Martens hardness, indentation modulus and radiopacity were investigated on these tooth replicas. Experienced dentists evaluated the suitability of the replicas for endodontic training by comparing them with real teeth in terms of appearance, anatomy, radiopacity, similarity to dentine during access opening, canal gauging and canal instrumentation. Data were analysed using the Kolmogorov-Smirnov and Mann-Whitney U-test. RESULTS: The greatest hardness values were recorded for human dentine (P < 0.001), followed by V-Print ee and the commercial tooth replica of Smile Factory. The greatest radiopacity was associated with VOC and dentine (P < 0.001) in comparison with the other materials tested. The appearance of the in-house printed tooth replicas was subjectively evaluated by the dentists as being more realistic than the commercially available products. No differences between the replicas was detected during mechanical instrumentation of root canals. CONCLUSION: None of the tooth replicas were able to simulate human dentine from the perspectives evaluated. V-Print ee had radiopacity comparable with dentine, but its hardness was not comparable with dentine.

3D Printing in Dentistry-State of the Art.

Three-dimensional (3D) printing is a rapidly developing technology that has gained widespread acceptance in dentistry. Compared to conventional (lost-wax technique) and subtractive computer numeric controlled methods, 3D printing offers process engineering advantages. Materials such as plastics, metals, and ceramics can be manufactured using various techniques. 3D printing was introduced over three decades ago. Today, it is experiencing rapid development due to the expiration of many patents and is often described as the key technology of the next industrial revolution. The transition to its clinical application in dentistry is highly dependent on the available materials, which must not only provide the required accuracy but also the necessary biological and physical properties. The aim of this work is to provide an up-to-date overview of the different printing techniques: stereolithography, digital light processing, photopolymer jetting, material jetting, binder jetting, selective laser sintering, selective laser melting, and fused filament fabrication. Additionally, particular attention is paid to the materials used in dentistry and their clinical application.

3D printed replicas for endodontic education.

AIM: To assess the feasibility of producing artificial teeth for endodontic training using 3D printing technology, to analyse the accuracy of the printing process, and to evaluate the teeth by students when used during training. METHODOLOGY: Sound extracted human teeth were selected, digitalized by cone beam computed tomography (CBCT) and appropriate software and finally reproduced by a stereolithographic printer. The printed teeth were scanned and compared with the original ones (trueness) and to one another (precision). Undergraduate dental students in the third and fourth years performed root canal treatment on printed molars and were subsequently asked to evaluate their experience with these compared to real teeth. RESULTS: The workflow was feasible for manufacturing 3D printed tooth replicas. The absolute deviation after printing (trueness) ranged from 50.9 to 104.3 µm. The values for precision ranged from 43.5 to 68.2 µm. Students reported great benefits in the use of the replicated teeth for training purposes. CONCLUSION: The presented workflow is feasible for any dental educational institution who has access to a CBCT unit and a stereolithographic printer. The accuracy of the printing process is suitable for the production of tooth replicas for endodontic training. Undergraduate students favoured the availability of these replicas and the fairness they ensured in training due to standardization.

3D-printed model for hands-on training in dental traumatology.

AIM: To assess the feasibility of creating a realistic model for hands-on training in dental traumatology using 3D printing technology, and then to investigate the added value of working with the website dentaltraumaguide.org. METHODOLOGY: With the use of special software applications, a model was designed based on the CBCT of the maxilla of a real patient that imitated several traumatic dental injuries. The model was reproduced using a stereolithographic printer to use the specimens in a hands-on training course on dental traumatology for undergraduate students in their final year in the Department of Conservative Dentistry and Periodontology in Munich, Germany. During the course, half of the participants had access to dentaltraumaguide.org, whereas the others did not. The students were then assessed according to their theoretical knowledge and practical performance in simulated treatment. These data were analysed by Kolmogorov-Smirnov test, unpaired t-test and Mann-Whitney U test. Subsequently, the participants were asked to evaluate the model. RESULTS: The workflow for manufacturing a model of dental traumatology for training purposes was practical and relatively inexpensive. In the evaluation process, the model was considered to be highly realistic and useful during an instructive hands-on training course. There were significant differences between the two groups in favour of using the dentaltraumaguide.org website. CONCLUSIONS: 3D printing technology offers new possibilities for training specific dental treatments that are currently difficult to imitate. The online platform dentaltraumaguide.org assisted students in correctly managing traumatic dental injuries.