3D Printed Tooth for Endodontic Training in Dental Education

3D Printed Tooth for Endodontic Training in Dental Education | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article 3D Printed Tooth for Endodontic Training in Dental Education Isabella Di Lorenzo, Michael del Hougne, Gabriel Krastl, Marc Schmitter, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6394920/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 20 Jun, 2025 Read the published version in Scientific Reports → Version 1 posted 11 You are reading this latest preprint version Abstract In dental education root canal treatment is primarily trained with natural teeth models or transparent acrylic blocks. A newly constructed, 3D-printed practice tooth can be produced cost-efficiently and reproducibly while based on a natural root canal anatomy. Based on a micro-CT scan of an extracted tooth number 36, a dataset was reconstructed (Autodesk Inventor 2019, Autodesk Inc.) and subsequently 3D printed (Form 3B, Formlabs Inc.). In a hands-on course, dental students performed root canal treatments on 3D-printed practice teeth. The practice teeth were prepared and filled. A reciprocating system (Reciproc, VDW GmbH) and a rotating preparation system (Pro Taper Next, Dentsply Sirona GmbH) were utilized. Students completed a questionnaire to evaluate practice materials, learning success, and learning process. The students rated suitability as a practice option (p < 0.001) and handling (p = 0.001) of the 3D-printed practice tooth, as well as natural tooth models, significantly better than acrylic blocks. Health sciences/Health care/Dentistry/Endodontics Health sciences/Health care/Dentistry/Dental education Health sciences/Health care/Dentistry/Dental education/Dental clinical teaching Health sciences/Health care/Dentistry/Dental equipment/Endodontic instruments/Endodontic files Health sciences/Health care/Dentistry/Dental treatments/Root canal treatment dental education 3D printing printed tooth RCT endodontic treatment additive manufacturing Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Transparent acrylic blocks are mainly utilized for practicing root canal treatments, with single-rooted (Flex Master practice block, V040245, VDW, Munich, Germany) and two-rooted (root canal study model, S1-U4, J. Morita, Tokyo, Japan) blocks. These blocks only represent a root canal system without tooth crown. Extracted natural teeth are applied for practice, as well, and can be anchored in a dental simulation unit. The use of natural teeth is of particular relevance in endodontic education due to their anatomical and characteristic features. Natural tooth models are inexpensive to produce, however, they pose hygienic and ethical challenges. The advantages and disadvantages of natural teeth compared to printed practice teeth have already been evaluated 1 . Their utilization has been criticized by some universities’ ethics committees, and the regulations for their use have been tightened. In addition to patient consent, further documentation of consent for university use is required. This increase in administrative effort could reduce dentists' willingness to collect extracted teeth 2 , 3 . The preparation and disinfection of the teeth are problematic, and the properties of the natural teeth change due to the preparation process 4 , 5 . Furthermore, generating a sufficient number of natural teeth with adequate quality represents a challenge 6 . As the anatomy of individual root canals is not identical and can differ significantly. This results in uneven learning outcomes, thus creating unfair conditions. In contrast, the 3D-printed practice tooth offers identical conditions for each tooth and does not pose any hygienic or ethical-legal issues. The aim of the study was to test and evaluate this practice option for learning root canal treatments in student education. The null hypothesis stated that students evaluated the existing training methods, i.e. transparent acrylic blocks and natural teeth models, superior to the 3D printed teeth. Materials and Methods Voluntary participation of participating students in the hands-on course and completion of the questionnaire were prerequisites. The study was approved by the Institutional Review Board (University of Würzburg, Germany) - the collected data had to be fully and irreversibly anonymized (20181116 01) and the use of anonymized existing scans and radiological data for the use of printed teeth in education was granted (20210823 02). Design of 3D Printed Tooth and Practice Materials An extracted left mandibular molar was voluntarily provided by a donor for study purposes and utilized in this study. Data was anonymized such that no references to the donor were possible. First, a micro-computed tomography of the extracted tooth was performed by the Fraunhofer Institute for Integrated Circuits (MetRIC Micro and Region of Interest, Fraunhofer IIS, Erlangen, Germany). Using Autodesk Inventor 2019 (Autodesk Inc., San Rafael, California, USA), the micro-computed tomography data was reconstructed and modified, as illustrated in Fig. 1 . This enabled a practice tooth with a realistic root canal anatomy and an access cavity. A mandibular model, previously utilized for educational training of caries excavation 1 , 7 , was modified for this study, as illustrated in Fig. 2 . It was anchored in a phantom head and served to fix the practice tooth, creating a patient-like situation. Additive Manufacturing of Practice Materials The additive manufacturing of the practice materials was conducted with a 3D printer employing the stereolithography (SLA) process, where a photosensitive resin is selectively hardened into a solid using laser technology. Form 2 (Formlabs GmbH 2024) and Form 3B (Formlabs GmbH 2024) were utilized. The Form 2 has a 140µm laser spot size, while the Form 3B has 85µm laser spot size and an XY resolution of 25µm. Both printers enable a layer thickness of up to 25 µm, depending on the resin. Items were prepared for 3D printing using the software PreForm 3.0.1 (Formlabs Inc., Somerville, Massachusetts, USA). As the resins vary in their material properties, i.e. hardness, color, and surface texture, different materials were used for the individual components of the practice teeth. Root and dentin portions were printed with White Resin V4 (Formlabs Inc.) and Model Resin V2 (Formlabs Inc.) and the enamel portions were made from a white, glass-filled resin (Rigid 4000 Resin, Formlabs Inc.). The latter had increased strength values and a smooth and white surface yielding in optical similarities to natural enamel. The tooth root with the crown dentin were printed separately from the enamel cap as different materials were utilized, as illustrated in Fig. 2 . Post-Processing and Finishing of Practice Materials The post-processing of the two materials followed the manufacturer's instructions. It included washing the objects with 100% isopropanol to remove any liquid resin, airdrying and hardening. For the dentin parts, the root canals were additionally rinsed with 100% isopropanol for 60 seconds per canal using disposable syringes with attached irrigation. The assembly included bonding the enamel cap to the dentin. Therefore, model resin (Model Resin V2, Formlabs Inc.) was first applied to the inside of the enamel cap with a disposable micro applicator and then placed on the dentin part. Excess resin was removed, and the bonding area was light-cured. Additionally, the enamel cap was coated with a thin layer of a light-curing one-component varnish, Plaquit (Dreve Dentamid GmbH, Unna, Germany) and light-cured, as well. The varnish layer gave the enamel cap a shiny surface, resulting in a more natural-looking final product, as illustrated in Fig. 3 . Hands-on course Fifth-year students participated in a voluntary hands-on at the Department of Dental Prosthetics, University Hospital of Würzburg. Students had already gained 1.5 years of clinical experience in performing root canal treatments. In their previous training courses, students had practiced root canal preparation and filling on transparent acrylic training blocks and natural tooth models. Thus, the students had experience handling acrylic training blocks (various models with one or two root canals) as well as natural teeth, including incisors, premolars, and molars. The hands-on course was held on two occasions, separated by 14 days and each student processed a total of three practice teeth, ensuring that both preparation systems were utilized. Additionally, a model was provided for determination of the length of the root canals. An electronic apex locator (DentaPort Root ZX, J. Morita Europe GmbH) and a hand-bent wire element were utilized with ultrasound gel (Ultraschall Gel Clear, Konix, Istanbul, Turkey) in the root canal system and apex region for enabling electrical conductivity, as illustrated in Fig. 4 . Questionnaire After the practical exercises were completed, each student voluntarily completed a questionnaire (see Table 1 ). The Institute for Medical Teaching and Training Research (IMLA) of the University of Würzburg collaborated for the design of the questionnaire. It was digitized with EvaSys (Electric Paper Evaluation System, evasys GmbH, 2023) and consisted of both free-text questions and predefined answer options that students could evaluate using a visual analog scale (VAS). The VAS had a 10 cm stretch without scaling and opposing statements at each end of the stretch. The questionnaire was divided into different sections. An introduction section was followed by a brief section regarding personal data. The properties of the printed teeth were compared with natural teeth, as well as other training options. The preparation methods were evaluated and learning outcomes and process were self-assessed. Free text questions solicited suggestions for improvements and the advantages of the printed teeth. Statistics Data processing was performed using Excel (Version 2301, Microsoft 365 Apps for Enterprise, Microsoft Corporation, 2023). IBM SPSS Statistics (Version 29.0.0.0, IBM Deutschland GmbH, 2023) and G*Power (Version 3.1.9.7) were used for statistical analysis. A descriptive analysis was conducted. Data was tested for normal distribution using the Shapiro-Wilk test. Statistical significance was assessed by the Mann-Whitney U test. When comparing more than two independent groups, the non-parametric Kruskal-Wallis test was applied, followed by Dunn's test with Bonferroni correction. The responses to the free text questions were manually grouped by two independent examiners, who analyzed them for common themes and categorized them accordingly. Internal consistency of the questionnaire was evaluated by computing Cronbach's alpha. The significance level was set at α = 0.05. Table 1 Questionnaire for hands-on course. 2. Personal data 2.2 Please enter your age 2.3 Have you completed an education in the dental sector prior to studying dentistry? 2.4 If yes, which one? 2.5 Please enter your gender 2.6 Which file system did you start with in the first session 2.7 The work in the preclinical course of restorative dentistry, especially the exercises in root canal treatment, came easily to me 2.8 The patient treatment in the clinical courses was easy for me 2.9 I take great pleasure in the practical aspects of studying dentistry 2.10 This is how I assess my manual skills. 2.11 During the preclinical and clinical courses, I had plenty of opportunities to practice root canal treatment. 3. Properties of printed teeth in comparison to natural teeth 3.1 Realistic feeling when determining the length of the root canal 3.2 Realism of the printed teeth 3.3 Realistic feeling during root canal preparation 3.4 Realistic feeling during root canal filling 3.5 Realistic root canal anatomy 3.6 Realistic pulp cavity 4. Characteristics of printed teeth in comparison with other training options 4.1 Suitability as a training option of printed tooth 4.2 Suitability as a training option of acrylic resin block 4.3 Suitability as a training option of natural teeth model 4.4 Handling of printed tooth 4.4 Handling of acrylic resin block 4.5 Handling of natural teeth model 5. Characteristics of preparation methods 5.1 Handling of Reciproc 5.2 Handling of ProTaper Next 5.3 I would utilize the Reciproc system myself 5.4 I would utilize the ProTaper Next system myself 6. Assessment of learning outcome 6.1 Subjective learning outcome with Reciproc 6.2 Subjective learning outcome with ProTaper Next 6.3 After this hands-on course I feel well prepared for root canal treatments 7. Assessment of learning process 7.1 The hands-on has sparked my enthusiasm to improve my skills in root canal preparation 7.2 For my studies I desire more exercises with 3D printed teeth 7.3 I can imagine the entire training in preparation for patient treatment being conducted solely with printed teeth 8. Free-text questions 8.1 What could be improved on the printed teeth? 8.2 Which advantages do printed teeth offer in dental education, in your opinion? Results Overall, 38 students completed the questionnaire - results can be found in Table S1. The completed questionnaires were manually entered into an Excel spreadsheet and the visual analog scale was read with a digital caliper and resulting percentages calculated. Results from 2.7 to 7.3 are visualized in a boxplot in Fig. 5 . The 38 students were composed of 29 women and 9 men. They had an average age of 24.9 (± 3.1) years. 6 students had completed an education prior to studying dentistry as dental technicians (n = 3) and medical and dental assistants (n = 3). The students rated their ease with previous exercises regarding endodontic treatments without patients at Ø 61.1% (± 21.7), and the patient treatment at the clinical courses at Ø 60.8% (± 18.1). Students enjoyed practical elements of their education at Ø 79.4% (± 16.7) and self-evaluated their manual skills at Ø 65.0% (± 12.4). Sufficient training opportunities for endodontic treatments within the preclinical and clinical courses were rated at Ø 57.0% (± 27.3). When evaluating the printed training teeth in comparison to natural teeth, the length measurement was rated Ø 64.9% (± 25.4) and the realism of the printed teeth at Ø 65.5% (± 16.8). The realistic feel during root canal preparation was rated at Ø 64.7% (± 20.8), during root canal filling at Ø 74.4% (± 15.9), realistic canal anatomy at Ø 73.9% (± 19.4), and realistic pulp chamber at Ø 71.6% (± 20.0). Suitability for practice was rated for printed tooth (Ø 84.0% ±15.4) significantly better (p < 0.001) compared to acrylic resin blocks (Ø 49.1% ±25.0), and the acrylic resin blocks as significantly less suitable (p < 0.001) compared to natural tooth models (Ø 88.2% ±13.1). Thus, compared to the natural tooth models, students rated the suitability of the printed tooth as a practice option slightly lower. The handling of the printed teeth (Ø 70.3% ±21.4) and the natural tooth models (Ø 70.9% ±19.3) were rated similarly, while acrylic resin blocks (Ø 46.4% ±28.5) were considered to have a more difficult handling. Students rated the handling of acrylic resin blocks as significantly more difficult compared to printed teeth (p = 0.001) and natural tooth models (p = 0.001). Regarding the preparation methods, the handling of the Reciproc system (Ø 74.6% ±20.9) was rated as more difficult compared to ProTaper Next (Ø 78.1 ± 18.1). However, when asked which system students preferred to use themselves, Reciproc (Ø 82.6 ± 20.0) was rated higher than ProTaper Next (Ø 76.0 ± 23.1). The subjective learning success was rated slightly higher for ProTaper Next (Ø 75.5 ± 18.9) compared to Reciproc (Ø 75.3 ± 18.3). Additionally, the students indicated that they felt well-prepared for root canal preparation due to the hands-on course (Ø 69.1 ± 18.3). Regarding the learning process, students rated at Ø 75.9% (± 17.1) that the hands-on course had sparked their enthusiasm to improve their root canal preparation skills. The question of whether more exercises with 3D printed teeth were desired in their education was rated at Ø 81.5% (± 16.1). However, the completion of the entire training for patient treatment with 3D-printed teeth was rated at only Ø 48.6% (± 30.9). The reliability analysis was determined for VAS items 2.7 to 7.3 with Cronbach's alpha, yielding a value of ∝ = 0.814. This can be considered as very high or excellent. The responses for the free-text questions were grouped and similar answers were categorized and tallied. The following suggestions for improvement of the 3D printed teeth were made: Improvement of the tooth's retention in the model (n = 30) Optimization of the material hardness (n = 7) Closing the access cavity, to integrate access cavity preparation into the practice (n = 5) Reducing the size of the access cavity (n = 2) Generating variations of root canal anatomies (n = 3) Making the pulp chamber darker (n = 1) Simulation of denticles (n = 1) Providing the option to take length measurement radiographs (n = 1) Enabling self-determination of working length (n = 1) Optimizing the curvature of the canals (n = 1) The following advantages of the 3D printed tooth for education were stated: Realistic representation (n = 24) Good practice opportunity in preparation of patient treatments (n = 10) Ability to practice with alternating root canal anatomies (n = 7) Less preparation efforts required compared to natural tooth models (n = 4) Cost-effective production (n = 4) Easier to perform root canal treatment compared to natural tooth models (n = 3) Opportunity to practice with several teeth (n = 3) Conditions are fairer due to the same level of difficulty (n = 3) No risk to patients (n = 1) Teeth can easily be replaced (n = 1) Practice on a phantom head is possible (n = 1) Discussion The questionnaire results highlight the potential of the printed teeth and confirm their added value in dental education. 3D printing, an additive production process, was elemental to producing the teeth, as it enables the fabrication of cavities and root canals – this is not possible by subtractive production, such as milling. The high precision of Form 2 and Form 3B enabled the production of the teeth with filigree root canals. 3D printing of teeth provided a cost-effective production 8 . While 3D printing is an established method for producing training utensils, it also has the potential to manufacture dental prostheses for patient use when an appropriate resin is utilized 9 . Reymus et al. printed teeth for endodontic treatment training with a Form 2 and revealed a trueness ranging from 50,9 µm to 104,3 µm and a precision ranging from 43,5 µm to 68,2 µm. Overall, 3D printed teeth are suitable for production of teeth for endodontic treatment training in dental education 4 . As sufficient training opportunities for endodontic treatments within the preclinical and clinical courses were rated at Ø 57.0% (± 27.3), it is emphasized that more training is required, especially as the ease of endodontic treatments were rated at Ø 61.1% (± 21.7) without patients and at Ø 60.8% (± 18.1) in the clinical courses. Overall, the 3D printed tooth was rated significantly better than acrylic resin blocks regarding suitability for practice (p < 0,001) and handling (p = 0.001). This was enhanced by positive evaluations of realism of the printed teeth, feel during root canal preparation and filling, canal anatomy and pulp chamber. However, the suitability of the printed teeth as a practice option and handling were rated slightly lower than natural teeth, pointing out the limitations of simulation of natural teeth. This was also attested by students as a completion of the entire training for patient treatment with 3D-printed teeth was rated at only Ø 48.6% (± 30.9). Both preparation methods were evaluated similar at handling, however, students favored Reciproc. Providing varying systems enhances students’ experiences with root canal treatment. Similar subjective learning successes were attested and overall, students felt well-prepared for root canal preparation due to the hands-on course (Ø 69.1 ± 18.3). The hands-on course sparked students’ enthusiasm and there was great desire for further exercises with 3D printed teeth. Students valued the realistic representation (n = 24) and the good practice opportunity in preparation of patient treatments (n = 10). The method of this study required less preparation effort compared to natural tooth models (n = 4) and overall, a cost-effective production (n = 4). Each tooth required 0.97ml of resin at a cost of 0.17€ per unit. The printing process took 4 hours and 12 minutes for the dentin parts and 5 hours and 26 minutes for the enamel parts. However, improvements suggested by the students included an improvement of the tooth’s retention in the model (n = 30), which could be obtained by optimizing spacer between tooth and model or implementation of a retention element such as a screw. Although the access cavity was provided on purpose, aiding fair conditions and equal levels of difficulty (n = 3), students desired closing the access cavity (n = 5) or reducing its size (n = 2) to enhance the exercise. The findings of the questionnaire allowed to confidently rejecting the null hypothesis, as students evaluated the 3D printed teeth superior to transparent acrylic blocks and equal to natural teeth models. The type of questionnaire utilized in this study represents an established method which can be found in other studies 7 , 10 . The VAS provide an objective and reliable instrument with high validity 11 . In this study, 38 students participated in the hands-on course and completed the questionnaire. Therefore, the findings cannot be generalized. However, although the production costs are limited, the manual assembly was time-consuming and, in the context of hands-on courses, proved to be a labor-intensive process 10 , 12 . The material properties of the printable resins represent a limiting factor. Enamel is the hardest material produced by the body and therefore difficult to imitate 13 . Others concluded that students preferred extracted human teeth to 3D-printed teeth due to physical characteristics in endodontic training 14 . Other studies also recognized the benefits of artificial resin due to its multiple advantages but rejected it as a replacement for natural teeth 15 , 16 . Overall, the 3D printed teeth for training of root canal treatments revealed benefits for education. Conclusion The 3D-printed teeth allowed students to practice root canal treatment independently and with a targeted approach. They serve as a valuable alternative to existing training methods and could be further improved with future advancements. Overall, this realistic training method provides a fair and cost-effective learning environment without hygienic or ethical concerns. Declarations CRediT (Contribution Roles Taxonomy) Isabella Di Lorenzo Conceptualization, Data Curation, Formal Analysis, Investigation, Methodology, Resources, Validation, Visualization, Writing – Original Draft preparation, Writing – Review and Editing Michael del Hougne Formal analysis, Investigation, Methodology, Project administration, Resources, Supervision, Validation, Visualization, Writing – Review and Editing Gabriel Krastl Data Curation, Project Administration, Resources, Visualization, Writing – Review and Editing Marc Schmitter Data Curation, Project Administration, Resources, Visualization, Writing – Review and Editing Christian Höhne Conceptualization, Project administration, Resources, Supervision, Validation, Writing – Review and Editing All authors have read and agreed to the published version of the manuscript. Acknowledgements The authors gratefully acknowledge all colleagues and students involved in this study. Data availability statement All data needed to evaluate the conclusions in the paper are present in the paper. Additional Information Competing Interests The authors declare no competing interests. References Carnier, L., Del Hougne, M., Schmitter, M. & Höhne, C. 3D-printed tooth for caries excavation. BMC Med. Educ. 24 , 1243. 10.1186/s12909-024-06230-3 (2024). Holden, A. & Dracopoulos, S. A. Owning the tooth: exploring the ethical and legal issues relating to the use of extracted human teeth in dental education in Australia. Aust Dent. J. 62 , 146–151. 10.1111/adj.12493 (2017). Groß, D., Lenk, C. & Utzig, B. Normative Rahmenbedingungen der Rekrutierung und Nutzung extrahierter Zähne in Forschung und Lehre. Reymus, M. et al. 3D printed replicas for endodontic education. Int. Endod J. 52 , 123–130. 10.1111/iej.12964 (2019). Tchorz, J. P. et al. Pre-clinical endodontic training with artificial instead of extracted human teeth: does the type of exercise have an influence on clinical endodontic outcomes? Int. Endod J. 48 , 888–893. 10.1111/iej.12385 (2015). Osnes, C. et al. Investigating the construct validity of a haptic virtual caries simulation for dental education. BMJ Simul. Technol. Enhanc Learn. 7 , 81–85. 10.1136/bmjstel-2019-000549 (2021). Höhne, C., Del Hougne, M., Gärtner, L., Winter, A. & Schmitter, M. Modular training model for education of students in restorative and prosthodontic dentistry. Eur. J. Dent. Educ. 28 , 347–357. 10.1111/eje.12956 (2024). Welk, A. et al. German dental faculty attitudes towards computer-assisted learning and their correlation with personal and professional profiles. Eur. J. Dent. Educ. 9 , 123–130. 10.1111/j.1600-0579.2005.00370.x (2005). Del Hougne, M., Di Lorenzo, I., Höhne, C. & Schmitter, M. A retrospective cohort study on 3D printed temporary crowns. Sci. Rep. 14 , 17295. 10.1038/s41598-024-68354-2 (2024). Del Hougne, M., Behr, G., Schmitter, M. & Höhne, C. 3D printed teeth with adhesive bridge preparation guide. Sci. Rep. 14 , 22017. 10.1038/s41598-024-73433-5 (2024). Schmitter, M., List, T. & Wirz, S. [The assessment of pain intensity using one-dimensional scales]. Z. Evid. Fortbild. Qual. Gesundhwes . 107 , 279–284. 10.1016/j.zefq.2013.05.008 (2013). Schwindling, F. S. et al. Establishing CAD/CAM in Preclinical Dental Education: Evaluation of a Hands-On Module. J. Dent. Educ. 79 , 1215–1221 (2015). Craig, R. G. & Peyton, F. A. The micro-hardness of enamel and dentin. J. Dent. Res. 37 , 661–668. 10.1177/00220345580370041301 (1958). Kolling, M. et al. Students' perception of three-dimensionally printed teeth in endodontic training. Eur. J. Dent. Educ. 26 , 653–661. 10.1111/eje.12743 (2022). Al-Sudani, D. I. & Basudan, S. O. Students' perceptions of pre-clinical endodontic training with artificial teeth compared to extracted human teeth. Eur. J. Dent. Educ. 21 , e72–e75. 10.1111/eje.12223 (2017). Luz, D. et al. Preparation time and perceptions of Brazilian specialists and dental students regarding simulated root canals for endodontic teaching: a preliminary study. J. Dent. Educ. 79 , 56–63. 10.1002/j.0022-0337.2015.79.1.tb05857.x (2015). Additional Declarations No competing interests reported. Supplementary Files SupplementaryTables.docx Cite Share Download PDF Status: Published Journal Publication published 20 Jun, 2025 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 26 May, 2025 Reviews received at journal 26 May, 2025 Reviewers agreed at journal 16 May, 2025 Reviewers agreed at journal 09 May, 2025 Reviews received at journal 24 Apr, 2025 Reviewers agreed at journal 23 Apr, 2025 Reviewers invited by journal 21 Apr, 2025 Editor assigned by journal 15 Apr, 2025 Editor invited by journal 14 Apr, 2025 Submission checks completed at journal 12 Apr, 2025 First submitted to journal 07 Apr, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Krastl","email":"","orcid":"","institution":"University of Würzburg","correspondingAuthor":false,"prefix":"","firstName":"Gabriel","middleName":"","lastName":"Krastl","suffix":""},{"id":439567156,"identity":"e96f6c59-1678-4c4e-b653-0ce58dde1046","order_by":3,"name":"Marc Schmitter","email":"","orcid":"","institution":"University of Würzburg","correspondingAuthor":false,"prefix":"","firstName":"Marc","middleName":"","lastName":"Schmitter","suffix":""},{"id":439567157,"identity":"496762a8-c29b-427e-bb4a-bccc3bb7c8d0","order_by":4,"name":"Christian Höhne","email":"","orcid":"","institution":"University of Würzburg","correspondingAuthor":false,"prefix":"","firstName":"Christian","middleName":"","lastName":"Höhne","suffix":""}],"badges":[],"createdAt":"2025-04-07 13:53:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6394920/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6394920/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-025-06081-y","type":"published","date":"2025-06-20T15:57:52+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":80584729,"identity":"01369195-e23c-4ce9-b2f3-51f1b4b0712a","added_by":"auto","created_at":"2025-04-15 00:25:25","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":38927,"visible":true,"origin":"","legend":"\u003cp\u003eAnatomy of the practice tooth, schematic illustration.\u003cbr\u003e\na: transparent visualization of the root canal system\u003cbr\u003e\nb: lateral view\u003cbr\u003e\nc: occlusal view with access cavity\u003cbr\u003e\n(Source: own figure)\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6394920/v1/1a5bd75b5da2bbab872fb920.jpeg"},{"id":80584726,"identity":"8c6b107f-e8ea-4664-b1c3-41f412dc2494","added_by":"auto","created_at":"2025-04-15 00:25:25","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":17241,"visible":true,"origin":"","legend":"\u003cp\u003e3D-printed model, schematic illustration. from basal: model, gingival mask, holder for endodontic tooth, root and crown dentin, enamel cap (Source: own figure)\u003c/p\u003e","description":"","filename":"floatimage214.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6394920/v1/e0856e1ab08893d30086dd48.jpeg"},{"id":80584730,"identity":"7a05f961-2390-4dc5-9612-8bc9ce1a7907","added_by":"auto","created_at":"2025-04-15 00:25:25","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":204876,"visible":true,"origin":"","legend":"\u003cp\u003e3D-printed tooth model production process. a: Dentin parts with resin residues on build platform b: Enamel parts with resin residues on build platform c: Washed objects with support structures\u003c/p\u003e\n\u003cp\u003ed: Enamel and dentin parts prepared for assembly\u003c/p\u003e\n\u003cp\u003ee: Assembled tooth (Source: own figure)\u003c/p\u003e","description":"","filename":"floatimage37.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6394920/v1/00a8aa176cc1622d3d107981.jpeg"},{"id":80585655,"identity":"c39d09a2-de4d-4adc-958f-c2a124a71513","added_by":"auto","created_at":"2025-04-15 00:41:25","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":56536,"visible":true,"origin":"","legend":"\u003cp\u003eDetermination of length of root canals.\u003cbr\u003e\n(Source: own figure)\u003c/p\u003e","description":"","filename":"floatimage4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6394920/v1/1ab9d7c858065b40a6f4d264.jpeg"},{"id":80585359,"identity":"1bb706f3-045e-4b9a-b676-751345c1b7d4","added_by":"auto","created_at":"2025-04-15 00:33:25","extension":"jpeg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":50884,"visible":true,"origin":"","legend":"\u003cp\u003eBoxplot with results from questionnaire (VAS items 2.7 to 7.3).\u003cbr\u003e\n(Source: own figure)\u003c/p\u003e","description":"","filename":"floatimage5.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6394920/v1/c5adea18e71347b8aca4ae42.jpeg"},{"id":85231415,"identity":"61c730b3-fa19-48c7-94b8-040293886eca","added_by":"auto","created_at":"2025-06-23 16:07:35","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":858595,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6394920/v1/8d0a8ecd-6e0f-4b3a-8026-eb68b495b2bd.pdf"},{"id":80584728,"identity":"01bfcc08-8819-412e-8ae2-ca83af50394c","added_by":"auto","created_at":"2025-04-15 00:25:25","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":19770,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryTables.docx","url":"https://assets-eu.researchsquare.com/files/rs-6394920/v1/63cd1d2bbae77ea69c882d29.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"3D Printed Tooth for Endodontic Training in Dental Education","fulltext":[{"header":"Introduction","content":"\u003cp\u003eTransparent acrylic blocks are mainly utilized for practicing root canal treatments, with single-rooted (Flex Master practice block, V040245, VDW, Munich, Germany) and two-rooted (root canal study model, S1-U4, J. Morita, Tokyo, Japan) blocks. These blocks only represent a root canal system without tooth crown.\u003c/p\u003e \u003cp\u003eExtracted natural teeth are applied for practice, as well, and can be anchored in a dental simulation unit. The use of natural teeth is of particular relevance in endodontic education due to their anatomical and characteristic features. Natural tooth models are inexpensive to produce, however, they pose hygienic and ethical challenges. The advantages and disadvantages of natural teeth compared to printed practice teeth have already been evaluated \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eTheir utilization has been criticized by some universities\u0026rsquo; ethics committees, and the regulations for their use have been tightened. In addition to patient consent, further documentation of consent for university use is required. This increase in administrative effort could reduce dentists' willingness to collect extracted teeth \u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e,\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. The preparation and disinfection of the teeth are problematic, and the properties of the natural teeth change due to the preparation process \u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e,\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. Furthermore, generating a sufficient number of natural teeth with adequate quality represents a challenge \u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. As the anatomy of individual root canals is not identical and can differ significantly. This results in uneven learning outcomes, thus creating unfair conditions. In contrast, the 3D-printed practice tooth offers identical conditions for each tooth and does not pose any hygienic or ethical-legal issues.\u003c/p\u003e \u003cp\u003eThe aim of the study was to test and evaluate this practice option for learning root canal treatments in student education.\u003c/p\u003e \u003cp\u003eThe null hypothesis stated that students evaluated the existing training methods, i.e. transparent acrylic blocks and natural teeth models, superior to the 3D printed teeth.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eVoluntary participation of participating students in the hands-on course and completion of the questionnaire were prerequisites. The study was approved by the Institutional Review Board (University of W\u0026uuml;rzburg, Germany) - the collected data had to be fully and irreversibly anonymized (20181116 01) and the use of anonymized existing scans and radiological data for the use of printed teeth in education was granted (20210823 02).\u003c/p\u003e\n\u003cp\u003eDesign of 3D Printed Tooth and Practice Materials\u003c/p\u003e\n\u003cp\u003eAn extracted left mandibular molar was voluntarily provided by a donor for study purposes and utilized in this study. Data was anonymized such that no references to the donor were possible. First, a micro-computed tomography of the extracted tooth was performed by the Fraunhofer Institute for Integrated Circuits (MetRIC Micro and Region of Interest, Fraunhofer IIS, Erlangen, Germany). Using Autodesk Inventor 2019 (Autodesk Inc., San Rafael, California, USA), the micro-computed tomography data was reconstructed and modified, as illustrated in Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e. This enabled a practice tooth with a realistic root canal anatomy and an access cavity.\u003c/p\u003e\n\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003cdiv id=\"Sec4\" class=\"Section3\"\u003e\n \u003cdiv id=\"Sec5\" class=\"Section4\"\u003e\n \u003cp\u003eA mandibular model, previously utilized for educational training of caries excavation \u003csup\u003e\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e, was modified for this study, as illustrated in Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e. It was anchored in a phantom head and served to fix the practice tooth, creating a patient-like situation.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\n \u003cp\u003eAdditive Manufacturing of Practice Materials\u003c/p\u003e\n \u003cp\u003eThe additive manufacturing of the practice materials was conducted with a 3D printer employing the stereolithography (SLA) process, where a photosensitive resin is selectively hardened into a solid using laser technology. Form 2 (Formlabs GmbH 2024) and Form 3B (Formlabs GmbH 2024) were utilized. The Form 2 has a 140\u0026micro;m laser spot size, while the Form 3B has 85\u0026micro;m laser spot size and an XY resolution of 25\u0026micro;m. Both printers enable a layer thickness of up to 25 \u0026micro;m, depending on the resin.\u003c/p\u003e\n \u003cp\u003eItems were prepared for 3D printing using the software PreForm 3.0.1 (Formlabs Inc., Somerville, Massachusetts, USA). As the resins vary in their material properties, i.e. hardness, color, and surface texture, different materials were used for the individual components of the practice teeth.\u003c/p\u003e\n \u003cp\u003eRoot and dentin portions were printed with White Resin V4 (Formlabs Inc.) and Model Resin V2 (Formlabs Inc.) and the enamel portions were made from a white, glass-filled resin (Rigid 4000 Resin, Formlabs Inc.). The latter had increased strength values and a smooth and white surface yielding in optical similarities to natural enamel. The tooth root with the crown dentin were printed separately from the enamel cap as different materials were utilized, as illustrated in Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e\n \u003cp\u003ePost-Processing and Finishing of Practice Materials\u003c/p\u003e\n \u003cp\u003eThe post-processing of the two materials followed the manufacturer\u0026apos;s instructions. It included washing the objects with 100% isopropanol to remove any liquid resin, airdrying and hardening. For the dentin parts, the root canals were additionally rinsed with 100% isopropanol for 60 seconds per canal using disposable syringes with attached irrigation.\u003c/p\u003e\n \u003cp\u003eThe assembly included bonding the enamel cap to the dentin. Therefore, model resin (Model Resin V2, Formlabs Inc.) was first applied to the inside of the enamel cap with a disposable micro applicator and then placed on the dentin part. Excess resin was removed, and the bonding area was light-cured. Additionally, the enamel cap was coated with a thin layer of a light-curing one-component varnish, Plaquit (Dreve Dentamid GmbH, Unna, Germany) and light-cured, as well. The varnish layer gave the enamel cap a shiny surface, resulting in a more natural-looking final product, as illustrated in Fig. \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n \u003cp\u003eHands-on course\u003c/p\u003e\n \u003cp\u003eFifth-year students participated in a voluntary hands-on at the Department of Dental Prosthetics, University Hospital of W\u0026uuml;rzburg.\u003c/p\u003e\n \u003cp\u003eStudents had already gained 1.5 years of clinical experience in performing root canal treatments. In their previous training courses, students had practiced root canal preparation and filling on transparent acrylic training blocks and natural tooth models. Thus, the students had experience handling acrylic training blocks (various models with one or two root canals) as well as natural teeth, including incisors, premolars, and molars.\u003c/p\u003e\n \u003cp\u003eThe hands-on course was held on two occasions, separated by 14 days and each student processed a total of three practice teeth, ensuring that both preparation systems were utilized.\u003c/p\u003e\n \u003cp\u003eAdditionally, a model was provided for determination of the length of the root canals. An electronic apex locator (DentaPort Root ZX, J. Morita Europe GmbH) and a hand-bent wire element were utilized with ultrasound gel (Ultraschall Gel Clear, Konix, Istanbul, Turkey) in the root canal system and apex region for enabling electrical conductivity, as illustrated in Fig. \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n \u003cp\u003eQuestionnaire\u003c/p\u003e\n \u003cp\u003eAfter the practical exercises were completed, each student voluntarily completed a questionnaire (see Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). The Institute for Medical Teaching and Training Research (IMLA) of the University of W\u0026uuml;rzburg collaborated for the design of the questionnaire. It was digitized with EvaSys (Electric Paper Evaluation System, evasys GmbH, 2023) and consisted of both free-text questions and predefined answer options that students could evaluate using a visual analog scale (VAS). The VAS had a 10 cm stretch without scaling and opposing statements at each end of the stretch.\u003c/p\u003e\n \u003cp\u003eThe questionnaire was divided into different sections. An introduction section was followed by a brief section regarding personal data. The properties of the printed teeth were compared with natural teeth, as well as other training options. The preparation methods were evaluated and learning outcomes and process were self-assessed. Free text questions solicited suggestions for improvements and the advantages of the printed teeth.\u003c/p\u003e\n \u003cp\u003eStatistics\u003c/p\u003e\n \u003cp\u003eData processing was performed using Excel (Version 2301, Microsoft 365 Apps for Enterprise, Microsoft Corporation, 2023). IBM SPSS Statistics (Version 29.0.0.0, IBM Deutschland GmbH, 2023) and G*Power (Version 3.1.9.7) were used for statistical analysis. A descriptive analysis was conducted. Data was tested for normal distribution using the Shapiro-Wilk test. Statistical significance was assessed by the Mann-Whitney U test. When comparing more than two independent groups, the non-parametric Kruskal-Wallis test was applied, followed by Dunn\u0026apos;s test with Bonferroni correction. The responses to the free text questions were manually grouped by two independent examiners, who analyzed them for common themes and categorized them accordingly. Internal consistency of the questionnaire was evaluated by computing Cronbach\u0026apos;s alpha. The significance level was set at \u0026alpha;\u0026thinsp;=\u0026thinsp;0.05.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eQuestionnaire for hands-on course.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"1\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e2. Personal data\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.2 Please enter your age\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.3 Have you completed an education in the dental sector prior to studying dentistry?\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.4 If yes, which one?\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.5 Please enter your gender\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.6 Which file system did you start with in the first session\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.7 The work in the preclinical course of restorative dentistry, especially the exercises in root canal treatment, came easily to me\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.8 The patient treatment in the clinical courses was easy for me\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.9 I take great pleasure in the practical aspects of studying dentistry\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.10 This is how I assess my manual skills.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.11 During the preclinical and clinical courses, I had plenty of opportunities to practice root canal treatment.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3. Properties of printed teeth in comparison to natural teeth\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.1 Realistic feeling when determining the length of the root canal\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.2 Realism of the printed teeth\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.3 Realistic feeling during root canal preparation\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.4 Realistic feeling during root canal filling\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.5 Realistic root canal anatomy\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.6 Realistic pulp cavity\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4. Characteristics of printed teeth in comparison with other training options\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.1 Suitability as a training option of printed tooth\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.2 Suitability as a training option of acrylic resin block\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.3 Suitability as a training option of natural teeth model\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.4 Handling of printed tooth\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.4 Handling of acrylic resin block\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.5 Handling of natural teeth model\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5. Characteristics of preparation methods\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.1 Handling of Reciproc\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.2 Handling of ProTaper Next\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.3 I would utilize the Reciproc system myself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.4 I would utilize the ProTaper Next system myself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6. Assessment of learning outcome\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.1 Subjective learning outcome with Reciproc\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.2 Subjective learning outcome with ProTaper Next\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.3 After this hands-on course I feel well prepared for root canal treatments\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7. Assessment of learning process\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.1 The hands-on has sparked my enthusiasm to improve my skills in root canal preparation\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.2 For my studies I desire more exercises with 3D printed teeth\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.3 I can imagine the entire training in preparation for patient treatment being conducted solely with printed teeth\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8. Free-text questions\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.1 What could be improved on the printed teeth?\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.2 Which advantages do printed teeth offer in dental education, in your opinion?\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eOverall, 38 students completed the questionnaire - results can be found in Table S1. The completed questionnaires were manually entered into an Excel spreadsheet and the visual analog scale was read with a digital caliper and resulting percentages calculated. Results from 2.7 to 7.3 are visualized in a boxplot in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eThe 38 students were composed of 29 women and 9 men. They had an average age of 24.9 (\u0026plusmn;\u0026thinsp;3.1) years. 6 students had completed an education prior to studying dentistry as dental technicians (n\u0026thinsp;=\u0026thinsp;3) and medical and dental assistants (n\u0026thinsp;=\u0026thinsp;3). The students rated their ease with previous exercises regarding endodontic treatments without patients at \u0026Oslash; 61.1% (\u0026plusmn;\u0026thinsp;21.7), and the patient treatment at the clinical courses at \u0026Oslash; 60.8% (\u0026plusmn;\u0026thinsp;18.1). Students enjoyed practical elements of their education at \u0026Oslash; 79.4% (\u0026plusmn;\u0026thinsp;16.7) and self-evaluated their manual skills at \u0026Oslash; 65.0% (\u0026plusmn;\u0026thinsp;12.4). Sufficient training opportunities for endodontic treatments within the preclinical and clinical courses were rated at \u0026Oslash; 57.0% (\u0026plusmn;\u0026thinsp;27.3).\u003c/p\u003e \u003cp\u003eWhen evaluating the printed training teeth in comparison to natural teeth, the length measurement was rated \u0026Oslash; 64.9% (\u0026plusmn;\u0026thinsp;25.4) and the realism of the printed teeth at \u0026Oslash; 65.5% (\u0026plusmn;\u0026thinsp;16.8). The realistic feel during root canal preparation was rated at \u0026Oslash; 64.7% (\u0026plusmn;\u0026thinsp;20.8), during root canal filling at \u0026Oslash; 74.4% (\u0026plusmn;\u0026thinsp;15.9), realistic canal anatomy at \u0026Oslash; 73.9% (\u0026plusmn;\u0026thinsp;19.4), and realistic pulp chamber at \u0026Oslash; 71.6% (\u0026plusmn;\u0026thinsp;20.0).\u003c/p\u003e \u003cp\u003eSuitability for practice was rated for printed tooth (\u0026Oslash; 84.0% \u0026plusmn;15.4) significantly better (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) compared to acrylic resin blocks (\u0026Oslash; 49.1% \u0026plusmn;25.0), and the acrylic resin blocks as significantly less suitable (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) compared to natural tooth models (\u0026Oslash; 88.2% \u0026plusmn;13.1). Thus, compared to the natural tooth models, students rated the suitability of the printed tooth as a practice option slightly lower.\u003c/p\u003e \u003cp\u003eThe handling of the printed teeth (\u0026Oslash; 70.3% \u0026plusmn;21.4) and the natural tooth models (\u0026Oslash; 70.9% \u0026plusmn;19.3) were rated similarly, while acrylic resin blocks (\u0026Oslash; 46.4% \u0026plusmn;28.5) were considered to have a more difficult handling. Students rated the handling of acrylic resin blocks as significantly more difficult compared to printed teeth (p\u0026thinsp;=\u0026thinsp;0.001) and natural tooth models (p\u0026thinsp;=\u0026thinsp;0.001).\u003c/p\u003e \u003cp\u003eRegarding the preparation methods, the handling of the Reciproc system (\u0026Oslash; 74.6% \u0026plusmn;20.9) was rated as more difficult compared to ProTaper Next (\u0026Oslash; 78.1\u0026thinsp;\u0026plusmn;\u0026thinsp;18.1). However, when asked which system students preferred to use themselves, Reciproc (\u0026Oslash; 82.6\u0026thinsp;\u0026plusmn;\u0026thinsp;20.0) was rated higher than ProTaper Next (\u0026Oslash; 76.0\u0026thinsp;\u0026plusmn;\u0026thinsp;23.1).\u003c/p\u003e \u003cp\u003eThe subjective learning success was rated slightly higher for ProTaper Next (\u0026Oslash; 75.5\u0026thinsp;\u0026plusmn;\u0026thinsp;18.9) compared to Reciproc (\u0026Oslash; 75.3\u0026thinsp;\u0026plusmn;\u0026thinsp;18.3). Additionally, the students indicated that they felt well-prepared for root canal preparation due to the hands-on course (\u0026Oslash; 69.1\u0026thinsp;\u0026plusmn;\u0026thinsp;18.3).\u003c/p\u003e \u003cp\u003eRegarding the learning process, students rated at \u0026Oslash; 75.9% (\u0026plusmn;\u0026thinsp;17.1) that the hands-on course had sparked their enthusiasm to improve their root canal preparation skills. The question of whether more exercises with 3D printed teeth were desired in their education was rated at \u0026Oslash; 81.5% (\u0026plusmn;\u0026thinsp;16.1). However, the completion of the entire training for patient treatment with 3D-printed teeth was rated at only \u0026Oslash; 48.6% (\u0026plusmn;\u0026thinsp;30.9).\u003c/p\u003e \u003cp\u003eThe reliability analysis was determined for VAS items 2.7 to 7.3 with Cronbach's alpha, yielding a value of \u0026prop; = 0.814. This can be considered as very high or excellent.\u003c/p\u003e \u003cp\u003eThe responses for the free-text questions were grouped and similar answers were categorized and tallied.\u003c/p\u003e \u003cp\u003eThe following suggestions for improvement of the 3D printed teeth were made:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eImprovement of the tooth's retention in the model (n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eOptimization of the material hardness (n\u0026thinsp;=\u0026thinsp;7)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eClosing the access cavity, to integrate access cavity preparation into the practice (n\u0026thinsp;=\u0026thinsp;5)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eReducing the size of the access cavity (n\u0026thinsp;=\u0026thinsp;2)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eGenerating variations of root canal anatomies (n\u0026thinsp;=\u0026thinsp;3)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eMaking the pulp chamber darker (n\u0026thinsp;=\u0026thinsp;1)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eSimulation of denticles (n\u0026thinsp;=\u0026thinsp;1)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eProviding the option to take length measurement radiographs (n\u0026thinsp;=\u0026thinsp;1)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eEnabling self-determination of working length (n\u0026thinsp;=\u0026thinsp;1)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eOptimizing the curvature of the canals (n\u0026thinsp;=\u0026thinsp;1)\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003eThe following advantages of the 3D printed tooth for education were stated:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eRealistic representation (n\u0026thinsp;=\u0026thinsp;24)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eGood practice opportunity in preparation of patient treatments (n\u0026thinsp;=\u0026thinsp;10)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eAbility to practice with alternating root canal anatomies (n\u0026thinsp;=\u0026thinsp;7)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eLess preparation efforts required compared to natural tooth models (n\u0026thinsp;=\u0026thinsp;4)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eCost-effective production (n\u0026thinsp;=\u0026thinsp;4)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eEasier to perform root canal treatment compared to natural tooth models (n\u0026thinsp;=\u0026thinsp;3)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eOpportunity to practice with several teeth (n\u0026thinsp;=\u0026thinsp;3)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eConditions are fairer due to the same level of difficulty (n\u0026thinsp;=\u0026thinsp;3)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eNo risk to patients (n\u0026thinsp;=\u0026thinsp;1)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eTeeth can easily be replaced (n\u0026thinsp;=\u0026thinsp;1)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003ePractice on a phantom head is possible (n\u0026thinsp;=\u0026thinsp;1)\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe questionnaire results highlight the potential of the printed teeth and confirm their added value in dental education.\u003c/p\u003e \u003cp\u003e3D printing, an additive production process, was elemental to producing the teeth, as it enables the fabrication of cavities and root canals \u0026ndash; this is not possible by subtractive production, such as milling. The high precision of Form 2 and Form 3B enabled the production of the teeth with filigree root canals. 3D printing of teeth provided a cost-effective production \u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. While 3D printing is an established method for producing training utensils, it also has the potential to manufacture dental prostheses for patient use when an appropriate resin is utilized \u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e. Reymus et al. printed teeth for endodontic treatment training with a Form 2 and revealed a trueness ranging from 50,9 \u0026micro;m to 104,3 \u0026micro;m and a precision ranging from 43,5 \u0026micro;m to 68,2 \u0026micro;m. Overall, 3D printed teeth are suitable for production of teeth for endodontic treatment training in dental education \u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. As sufficient training opportunities for endodontic treatments within the preclinical and clinical courses were rated at \u0026Oslash; 57.0% (\u0026plusmn;\u0026thinsp;27.3), it is emphasized that more training is required, especially as the ease of endodontic treatments were rated at \u0026Oslash; 61.1% (\u0026plusmn;\u0026thinsp;21.7) without patients and at \u0026Oslash; 60.8% (\u0026plusmn;\u0026thinsp;18.1) in the clinical courses. Overall, the 3D printed tooth was rated significantly better than acrylic resin blocks regarding suitability for practice (p\u0026thinsp;\u0026lt;\u0026thinsp;0,001) and handling (p\u0026thinsp;=\u0026thinsp;0.001). This was enhanced by positive evaluations of realism of the printed teeth, feel during root canal preparation and filling, canal anatomy and pulp chamber. However, the suitability of the printed teeth as a practice option and handling were rated slightly lower than natural teeth, pointing out the limitations of simulation of natural teeth. This was also attested by students as a completion of the entire training for patient treatment with 3D-printed teeth was rated at only \u0026Oslash; 48.6% (\u0026plusmn;\u0026thinsp;30.9). Both preparation methods were evaluated similar at handling, however, students favored Reciproc. Providing varying systems enhances students\u0026rsquo; experiences with root canal treatment. Similar subjective learning successes were attested and overall, students felt well-prepared for root canal preparation due to the hands-on course (\u0026Oslash; 69.1\u0026thinsp;\u0026plusmn;\u0026thinsp;18.3). The hands-on course sparked students\u0026rsquo; enthusiasm and there was great desire for further exercises with 3D printed teeth. Students valued the realistic representation (n\u0026thinsp;=\u0026thinsp;24) and the good practice opportunity in preparation of patient treatments (n\u0026thinsp;=\u0026thinsp;10). The method of this study required less preparation effort compared to natural tooth models (n\u0026thinsp;=\u0026thinsp;4) and overall, a cost-effective production (n\u0026thinsp;=\u0026thinsp;4). Each tooth required 0.97ml of resin at a cost of 0.17\u0026euro; per unit. The printing process took 4 hours and 12 minutes for the dentin parts and 5 hours and 26 minutes for the enamel parts. However, improvements suggested by the students included an improvement of the tooth\u0026rsquo;s retention in the model (n\u0026thinsp;=\u0026thinsp;30), which could be obtained by optimizing spacer between tooth and model or implementation of a retention element such as a screw. Although the access cavity was provided on purpose, aiding fair conditions and equal levels of difficulty (n\u0026thinsp;=\u0026thinsp;3), students desired closing the access cavity (n\u0026thinsp;=\u0026thinsp;5) or reducing its size (n\u0026thinsp;=\u0026thinsp;2) to enhance the exercise. The findings of the questionnaire allowed to confidently rejecting the null hypothesis, as students evaluated the 3D printed teeth superior to transparent acrylic blocks and equal to natural teeth models. The type of questionnaire utilized in this study represents an established method which can be found in other studies \u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e,\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. The VAS provide an objective and reliable instrument with high validity \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. In this study, 38 students participated in the hands-on course and completed the questionnaire. Therefore, the findings cannot be generalized. However, although the production costs are limited, the manual assembly was time-consuming and, in the context of hands-on courses, proved to be a labor-intensive process \u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e,\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe material properties of the printable resins represent a limiting factor. Enamel is the hardest material produced by the body and therefore difficult to imitate \u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. Others concluded that students preferred extracted human teeth to 3D-printed teeth due to physical characteristics in endodontic training \u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e. Other studies also recognized the benefits of artificial resin due to its multiple advantages but rejected it as a replacement for natural teeth \u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e,\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eOverall, the 3D printed teeth for training of root canal treatments revealed benefits for education.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe 3D-printed teeth allowed students to practice root canal treatment independently and with a targeted approach. They serve as a valuable alternative to existing training methods and could be further improved with future advancements. Overall, this realistic training method provides a fair and cost-effective learning environment without hygienic or ethical concerns.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eCRediT (Contribution Roles Taxonomy)\u003c/h2\u003e\n\u003cp\u003eIsabella Di Lorenzo\u003c/p\u003e\n\u003cp\u003eConceptualization, Data Curation, Formal Analysis, Investigation, Methodology, Resources, Validation, Visualization, Writing \u0026ndash; Original Draft preparation, Writing \u0026ndash; Review and Editing\u003c/p\u003e\n\u003cp\u003eMichael del Hougne\u003c/p\u003e\n\u003cp\u003eFormal analysis, Investigation, Methodology, Project administration, Resources, Supervision, Validation, Visualization, Writing \u0026ndash; Review and Editing\u003c/p\u003e\n\u003cp\u003eGabriel Krastl \u003c/p\u003e\n\u003cp\u003eData Curation, Project Administration, Resources, Visualization, Writing \u0026ndash; Review and Editing\u003c/p\u003e\n\u003cp\u003eMarc Schmitter\u003c/p\u003e\n\u003cp\u003eData Curation, Project Administration, Resources, Visualization, Writing \u0026ndash; Review and Editing\u003c/p\u003e\n\u003cp\u003eChristian H\u0026ouml;hne\u003c/p\u003e\n\u003cp\u003eConceptualization, Project administration, Resources, Supervision, Validation, Writing \u0026ndash; Review and Editing\u003c/p\u003e\n\u003cp\u003eAll authors have read and agreed to the published version of the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgements\u003c/h2\u003e \u003cp\u003eThe authors gratefully acknowledge all colleagues and students involved in this study.\u003c/p\u003e\u003ch2\u003eData availability statement\u003c/h2\u003e \u003cp\u003eAll data needed to evaluate the conclusions in the paper are present in the paper.\u003c/p\u003e \u003ch2\u003eAdditional Information\u003c/h2\u003e\u003ch2\u003eCompeting Interests\u003c/h2\u003e \u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eCarnier, L., Del Hougne, M., Schmitter, M. \u0026amp; H\u0026ouml;hne, C. 3D-printed tooth for caries excavation. \u003cem\u003eBMC Med. 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Educ.\u003c/em\u003e \u003cb\u003e79\u003c/b\u003e, 56\u0026ndash;63. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/j.0022-0337.2015.79.1.tb05857.x\u003c/span\u003e\u003cspan address=\"10.1002/j.0022-0337.2015.79.1.tb05857.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2015).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"dental education, 3D printing, printed tooth, RCT, endodontic treatment, additive manufacturing","lastPublishedDoi":"10.21203/rs.3.rs-6394920/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6394920/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIn dental education root canal treatment is primarily trained with natural teeth models or transparent acrylic blocks. A newly constructed, 3D-printed practice tooth can be produced cost-efficiently and reproducibly while based on a natural root canal anatomy.\u003c/p\u003e \u003cp\u003eBased on a micro-CT scan of an extracted tooth number 36, a dataset was reconstructed (Autodesk Inventor 2019, Autodesk Inc.) and subsequently 3D printed (Form 3B, Formlabs Inc.).\u003c/p\u003e \u003cp\u003eIn a hands-on course, dental students performed root canal treatments on 3D-printed practice teeth. The practice teeth were prepared and filled. A reciprocating system (Reciproc, VDW GmbH) and a rotating preparation system (Pro Taper Next, Dentsply Sirona GmbH) were utilized. Students completed a questionnaire to evaluate practice materials, learning success, and learning process.\u003c/p\u003e \u003cp\u003eThe students rated suitability as a practice option (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and handling (p\u0026thinsp;=\u0026thinsp;0.001) of the 3D-printed practice tooth, as well as natural tooth models, significantly better than acrylic blocks.\u003c/p\u003e","manuscriptTitle":"3D Printed Tooth for Endodontic Training in Dental Education","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-04-15 00:25:20","doi":"10.21203/rs.3.rs-6394920/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-05-26T17:44:15+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-26T08:11:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"163022124502679596590266755307884895204","date":"2025-05-16T14:18:04+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"169157401325869982057101643882855944708","date":"2025-05-09T18:29:11+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-24T11:14:16+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"170494170174187594422760432395089249298","date":"2025-04-23T06:01:53+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-04-21T05:54:30+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-04-15T04:36:55+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-04-14T13:40:15+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-04-12T12:07:01+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-04-07T13:44:01+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6ba818c6-1fe9-4d82-8d4d-4dee2514232c","owner":[],"postedDate":"April 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":46795448,"name":"Health sciences/Health care/Dentistry/Endodontics"},{"id":46795449,"name":"Health sciences/Health care/Dentistry/Dental education"},{"id":46795450,"name":"Health sciences/Health care/Dentistry/Dental education/Dental clinical teaching"},{"id":46795451,"name":"Health sciences/Health care/Dentistry/Dental equipment/Endodontic instruments/Endodontic files"},{"id":46795452,"name":"Health sciences/Health care/Dentistry/Dental treatments/Root canal treatment"}],"tags":[],"updatedAt":"2025-06-23T16:02:54+00:00","versionOfRecord":{"articleIdentity":"rs-6394920","link":"https://doi.org/10.1038/s41598-025-06081-y","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2025-06-20 15:57:52","publishedOnDateReadable":"June 20th, 2025"},"versionCreatedAt":"2025-04-15 00:25:20","video":"","vorDoi":"10.1038/s41598-025-06081-y","vorDoiUrl":"https://doi.org/10.1038/s41598-025-06081-y","workflowStages":[]},"version":"v1","identity":"rs-6394920","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6394920","identity":"rs-6394920","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}