Pre-clinical endodontic education outcomes between artificial versus extracted natural teeth: a systematic review

Effect of 3D printed teeth and virtual simulation system on the pre-clinical access cavity preparation training of senior dental undergraduates

BACKGROUND

The objective of the present study was to evaluate the effect of 3D printed teeth and virtual simulation system on the pre-clinical access cavity preparation training of senior dental undergraduates.

METHODS

The 3D printed teeth were manufactured based on the micro-CT data of an extracted lower first molar. Ninety-eight senior dental undergraduate students were required to finish the access cavity preparation of lower first molar within 20 min on plastic and 3D printed teeth on the manikin system as well as on a virtual simulation machine respectively with randomly selected sequences. Expert dentists scored the operated teeth. The scores from the virtual simulation system were also recorded. All the scores were analyzed and compared. Following the procedure, two questionnaires were sent to students to further evaluate the feelings and optimal training sequence.

RESULTS

No significant differences were found between plastic and 3D printed teeth scores, while virtual simulation achieved a valid/invalid area removal ratio of 96.86% ± 5.08% and 3.97% ± 1.85%, respectively. Most students found plastic teeth training the easiest and favored the three-training combination (36.36%). 71.42% of the students thought the virtual simulation training should be put at the first place of the three trainings. Over 80% of students agreed with incorporating 3D printed teeth and virtual simulation into their routine training courses. In addition, the general advantages and disadvantages of the virtual simulation system and 3D printed teeth training received almost equal recognition by students.

CONCLUSIONS

Virtual simulation system training + plastic teeth training + 3D printed teeth training might be the optimal training sequence. Virtual simulation system training could not completely replace the traditional training methods on the manikin system at the moment. With further modifications, 3D printed teeth could be expected to replace the plastic teeth for the pre-clinical access cavity preparation training.

Three-axis load analysis of high-speed handpiece on dental training teeth and computer-aided design/computer-aided manufacturing blocks

This study aimed to evaluate and compare the mechanical properties of dental training teeth with subtractive and additive computer-aided design/computer-aided manufacturing (CAD/CAM) materials used to fabricate dental simulation models. Therefore, the three-axis load generated during cutting movements, including drilling and milling performed using a dental handpiece, was measured and compared. The samples were cut vertically downward by 1.5 mm, horizontally by 6 mm, and vertically upward at a constant speed (1 mm/s), while the rotational speed of the bur was maintained at 200,000 rotations per minute. A three-axis load cell was used to measure the X-, Y-, and Z-axis loads on the specimen. The median value of the X-, Y-, and Z-axis measurements and the resultant load during the vertical-downward, horizontal, and vertical-upward movements were compared using a one-way analysis of variance and Tukey's post hoc test. For vertical downward movement, the drilling force of the dental training teeth was lower than that of Vita Enamic® and similar to that of Lava™ Ultimate. In contrast to subtractive CAD/CAM blocks, the drilling force of the dental training teeth was higher than that of 3D-printed resin blocks. Regarding horizontal movement, the milling force of dental training teeth was lower than that of Vita Enamic®. In contrast, the milling force of Nissin was similar to that of Lava™ Ultimate, while that of Frasaco was lower. Furthermore, compared to additive CAD/CAM blocks, the milling force of the dental training teeth was higher than that of 3D-printed resin blocks. Regarding vertical upward movement, the resultant loads of dental training teeth was lower than that of Vita Enamic®. Similarly, the resultant load of Nissin was similar to that of Lava™ Ultimate, while that of Frasaco was lower. Additionally, compared to additive CAD/CAM blocks, the resultant loads of the dental training teeth were similar to those of the 3D-printed resin blocks.

Evaluation of 3D-Printed Dog Teeth for Pre-clinical Training of Endodontic Therapy in Veterinary Dentistry

Artificial teeth in dental training have become a valuable tool for students to gain hands-on experience in a safe and controlled environment. This training method allows students to practice various dental procedures and develop their skills without putting patients at risk. Artificial teeth can be used to simulate dental conditions, allowing students to gain experience in dealing with various situations and techniques. Although previous studies in human dentistry have demonstrated the feasibility of using 3D-printed teeth for teaching endodontic procedures such as root canal therapy, similar research has yet to be conducted in the veterinary field. This study aimed to assess the feasibility of creating 3D-printed teeth from an adult dog skull and validate their use as an alternative training tool for root canal therapy in this species. For this, cone beam computed tomography images from a medium-sized dog skull were used to replicate its teeth using a digital 3D printing system. Then, artificial mandibular first molar teeth and a 24-question survey were sent to specialized veterinary dentistry practitioners in Brazil to assess their perception of the model's characteristics during endodontic treatment. In conclusion, it was feasible to create 3D-printed models of dog teeth with high accuracy for the endodontic system. Despite the differences in the properties of the two materials between natural and artificial teeth, it was possible to use the artificial tooth as a training device for conventional endodontic treatment in dogs. The reliability level for the survey was reported as good, displaying a reliability coefficient above 0.86.

Mastery Learning in Preclinical Endodontics Using Customized 3D-Printed Tooth Models for Deliberate Practice: An Application of Educational Design Research

INTRODUCTION

This study, conducted within an educational design research (EDR) framework, assessed the use of customized 3D-printed tooth models at various difficulty levels to enhance mastery learning and deliberate practice in preclinical endodontic training.

METHODS

The EDR was conducted in a preclinical endodontic training involving 42 third-year students. The study focused on developing and evaluating 3D-printed tooth models customized into 3 difficulty levels to facilitate mastery learning for the access opening procedure on upper anterior teeth. To promote deliberate practice, we ensured ample availability of these models. The evaluation combined quantitative analysis, using Friedman and Wilcoxon Signed-Rank tests to assess practice volume and performance, with qualitative feedback from interviews and focus groups, analyzed via content analysis.

RESULTS

There was a significant reduction in practice time across the different model levels, with students using an average of 1.5-1.8 models per level. No significant differences in performance scores were observed across levels and natural tooth (P = .333). Feedback highlighted the models' educational value in enhancing dental training, indicating their effectiveness in improving learning experiences and skill development in endodontic education.

CONCLUSIONS

The innovative design of a 3D-printed tooth model system, which features 3 levels of difficulty and was developed within an EDR framework, allowed for tailored learning progressions and ample practice opportunities. This significantly enhanced the endodontic training experience and skill development by providing varied and realistic challenges.

Modular training model for education of students in restorative and prosthodontic dentistry

INTRODUCTION

At the moment, no commercial model solution is available for the individualisation of the dentition depending on the clinical case scenario. Furthermore, the realistic training of most restorative and prosthodontic procedures on a single dental study model is not possible. The aim of this study was the creation of a new training model to fill this gap.

MATERIALS AND METHODS

Complete upper and lower jaw models were created based on existing scans and radiological data from a patient. All components for 100 complete models and 1128 teeth for the training were produced with a SLA-printer. Overall, 94 voluntary students attending the first and second preclinical course in prosthodontics tested the functionality of the model with three different tooth types against a standard dental study model and real teeth. After the training, the model was rated in a questionnaire.

RESULTS

The production of the models and teeth was feasible. The overall rating of the different teeth was worse for type I (Ø 3.6 ± 1.1), significantly better for type II (Ø 2.5 ± 1.0) and type III (Ø 2.4 ± 1.0) than a standard typodont tooth (Ø 2.7 ± 1.1). The new model was rated significantly better overall (Ø 2.6 ± 1.0) than the standard training model (Ø 3.0 ± 1.1).

CONCLUSIONS

The aim of this study was fulfilled. A superior training model was created with equivalent and better tooth types. The new teeth were outstanding in terms of cost-efficiency, appearance and feeling during preparation.

Students' experience and perceptions of undergraduate endodontic education in New Zealand

This study investigated the clinical experience and perceptions of New Zealand graduating dental students (2019 and 2020) towards endodontic teaching and their clinical learning outcomes using an online survey and clinical scenarios. Quantitative data were analysed using SPSS software, and qualitative data were analysed thematically. Responses were similar for both cohorts (response rates 74%, 2019; 73%, 2020). Endodontic teaching was valuable and interesting but difficult compared with other disciplines. Molar endodontics, finding canals and managing posture were challenging. Students felt more confident and less anxious when supervised by clinicians experienced in endodontics. Time management was the most anxiety-inducing factor and significantly related to clinical experience (p < 0.001). Overall, students appropriately applied knowledge in most areas of endodontics while holistic problem-solving in complex scenarios was variable. Maximising clinical experience and supervision from teachers experienced in endodontics are important for learning, improving confidence and reducing anxiety.

A comparison of online and face-to-face modalities in endodontic preclinical education: A retrospective study

PURPOSE

The aim of this study was to evaluate the competency of undergraduate students in following the principles of access cavity preparation and the radiographic quality of root canal filling in maxillary molar teeth in either online or face-to-face education courses during the novel coronavirus disease 2019 (COVID-19) pandemic.

METHODS

A total of 178 extracted maxillary molar teeth that underwent endodontic dental treatment by undergraduate students who completed the endodontic preclinical practice course online or face-to-face during the COVID-19 pandemic were retrospectively analyzed. A visual access cavity examination determined the form, width of the cavity, deroofing of the pulp chamber, and the presence of a perforation. Root canal fillings were examined radiographically on periapical radiographs for length, homogeneity, taper, and the presence of iatrogenic defects. Statistical analysis was performed using the chi-square test.

RESULTS

The incidence of incorrect form, wide cavities, and perforation was statistically higher in the online group than in the face-to-face group (p < 0.05). It was determined that root filling length and homogeneity were more successful in the face-to-face group (p < 0.05). When evaluated for iatrogenic errors, the presence of broken instruments was found to be significantly higher in the online group (p < 0.05). There was no significant difference between the groups in other iatrogenic errors and the taper of the root canal filling (p > 0.05).

CONCLUSION

The students who underwent face-to-face education were more successful in accessing cavity preparation and root canal fillings than the students who undertook online education.

Three-Dimensional Printed Tooth Model with Root Canal Ledge: A Novel Educational Tool for Endodontic Training

Ledge formation presents a significant challenge in endodontic treatment. Yet, there is still a lack of educational tooth models for hands-on practice. This study aimed to create and evaluate a tooth model for ledge management practice. A natural tooth with curved roots was collected for scientific use under ethics committee approval. Following initial root canal preparation, the tooth was scanned using micro-computed tomography (μCT) and 3D reconstructed. A K-file, created via computer-aided design (CAD), was partly inserted into the root canal wall of the 3D reconstructed tooth. By subtracting the K-file from the tooth, a tooth model with a root canal ledge was produced. The model was then 3D printed for a hands-on workshop. An eight-item Likert-scale questionnaire was administered to 20 postgraduate students and 10 endodontists to assess the model's quality and training effectiveness. In addition, the success rate of bypassing and correcting the root canal ledge was documented. The feedback from both the students and experts was positive, and the results of the Mann-Whitney U test indicated no statistically significant differences found between the two groups (p > 0.05). The success rate of the students and the experts was 85% and 100%, respectively. In future applications, this novel tooth model is expected to address the existing gap in endodontic education and provide benefits for dental practitioners.

Value of including loupes in prosthodontic and endodontic components of dental degrees: a systematic review

Background It is crucial dental students graduate with sound knowledge of endodontics and prosthodontics. The use of loupes is important for these due to their intricate nature, but there is currently no standardisation of curricula.Objective This systematic review investigates the value of including loupes in completing dental degrees and their benefits to dental students.Methods Literature was searched from inception to February 2022 in PubMed, Embase and Scopus. Articles included were primary studies of dental students studying endodontics or prosthodontics, which had outcomes related to the value of utilising loupes in learning, clinical application and ergonomics.Results A total of 1,489 articles were retrieved, of which 14 relevant articles were identified. These articles discussed student perceptions and the impact on visual acuity, ergonomic practices and dental procedures. Overall, students perceived that loupes increased self-confidence and allowed a greater operative view but were initially difficult to use. Using loupes resulted in greater visual acuity than no magnification and improved ergonomic practices by reducing neck angulation and improving posture. Students also received better grades when using loupes during cavity access preparation or root canal therapy.Conclusion The use of loupes by dental students can be beneficial if there is initial teaching on their use.

Rubric vs. numeric rating scale: agreement among evaluators on endodontic treatments performed by dental students

BACKGROUND

Students´ assessment should be carried out in an effective and objective manner, which reduces the possibility of different evaluators giving different scores, thus influencing the qualification obtained and the consistency of education. The aim of the present study was to determine the agreement among four evaluators and compare the overall scores awarded when assessing portfolios of endodontic preclinical treatments performed by dental students by using an analytic rubric and a numeric rating scale.

METHODS

A random sample of 42 portfolios performed by fourth-year dental students at preclinical endodontic practices were blindly assessed by four evaluators using two different evaluation methods: an analytic rubric specifically designed and a numeric rating scale. Six categories were analyzed: radiographic assessment, access preparation, shaping procedure, obturation, content of the portfolio, and presentation of the portfolio. The maximum global score was 10 points. The overall scores obtained with both methods from each evaluator were compared by Student's t, while agreement among evaluators was measured by Intraclass correlation coefficients (ICC). The influence of the difficulty of the endodontic treatment on the evaluators´ scores was analyzed by one-way ANOVA. Statistical tests were performed at a pre-set alpha of 0.05 using Stata 16.

RESULTS

Difficulty of canal treatment did not influence the scores of evaluators, irrespective of the evaluation method used. When the analytic rubric was used, inter-evaluator agreement was substantial for radiographic assessment, access preparation, shaping procedure, obturation, and overall scores. Inter-evaluator agreement ranged from moderate to fair with the numeric rating scale. Mean higher overall scores were achieved when numeric rating scale was used. Presentation and content of the portfolio showed slight and fair agreement, respectively, among evaluators, regardless the evaluation method applied.

CONCLUSIONS

Assessment guided by an analytic rubric allowed evaluators to reach higher levels of agreement than those obtained when using a numeric rating scale. However, the rubric negatively affected overall scores.

Application of 3D-printed teeth models in teaching dentistry students: A scoping review

INTRODUCTION

Both regular teaching of dentistry students and various training schemes for dentists primarily make use of the series teeth models, resin blocks or extracted teeth, whereas the 3D teeth models may well offer an alternative in this respect.

METHODS

PubMed and EMBASE were searched in September 2020. Eligibility of the studies was determined on whether they had made use of the 3D-printed teeth models in both pre- and post-graduate education in dentistry.

RESULTS

The final review embraced 15 studies. There were 659 (89.54%) student participants, and 77 (10.46%) dentists involved in those studies. Five studies addressed the prosthetic and surgical procedures, two-endodontics, one-paediatric dentistry and one-trauma management. The 3D-printed models were also used in the study focused on enhancing the students' manual dexterity, whilst making use of the PhantHome tool.

DISCUSSION

The 3D-printed teeth models developed for teaching purposes are used in various areas of dentistry. Their overall usefulness in acquiring the necessary hands-on skills for clinical work was acknowledged in all the studies under review, regardless of a specific procedure at issue. The 3D models effectively eliminate the hazard of cross-infection. Overall effectiveness of the soft tissue reproduction appears to be their weakest point indicated to date, especially in the surgical models.

CONCLUSIONS

The 3D-printed teeth models provide an alternative to the extracted ones, and the series teeth models in regular teaching practice. Participants of the studies under review thoroughly recommend introducing 3D models into any hands-on practice.

3D-Printed Teeth in Endodontics: Why, How, Problems and Future-A Narrative Review

Three-dimensional printing offers possibilities for the development of new models in endodontics. Numerous studies have used 3D-printed teeth; however, protocols for the standardization of studies still need to be developed. Another problem with 3D-printed teeth is the different areas of literature requested to understand the processes. This review aims to gather evidence about 3D-printed teeth on the following aspects: (1) why they are advantageous; (2) how they are manufactured; (3) problems they present; and (4) future research topics. Natural teeth are still the standard practice in ex vivo studies and pre-clinical courses, but they have several drawbacks. Printed teeth may overcome all limitations of natural teeth. Printing technology relies on 3D data and post-processing tools to form a 3D model, ultimately generating a prototype using 3D printers. The major concerns with 3D-printed teeth are the resin hardness and printing accuracy of the canal anatomy. Guidance is presented for future studies to solve the problems of 3D-printed teeth and develop well-established protocols, for the standardization of methods to be achieved. In the future, 3D-printed teeth have the possibility to become the gold standard in ex vivo studies and endodontic training.

Peracetic Acid: A Practical Alternative to Formalin for Disinfection of Extracted Human Teeth

Extracted human teeth provide the closest approximation to teeth in situ and play important roles in dental education and materials research. Since extracted teeth are potentially infectious, the Centers for Disease Control recommend their sterilization by autoclaving or disinfection by formalin immersion to ensure safe handling. However, autoclaving is not recommended for teeth with amalgam fillings and formalin is hazardous. The goal of the present study was to investigate the potential of peracetic acid (PA) as an alternative method to achieve reliable disinfection of freshly extracted teeth. A total of 80 extracted teeth were collected for this study. Whole teeth were incubated in one of four solutions for defined periods of time: sterile water (2 weeks), formalin (2 weeks), PA 1000 ppm (2 weeks), and PA 2000 ppm (1 week). After sectioning, the crown and root fragments were transferred into separate tubes containing brain–heart infusion broth and incubated at 37 °C under anaerobic conditions for 72 h. Absence of broth turbidity was used to assess effectiveness of disinfection. No turbidity was observed in any of the formalin-treated or peracetic acid-treated samples, signifying complete disinfection. Our results indicate that PA can effectively disinfect extracted human teeth, providing a reliable alternative to formalin and autoclaving.

Microbial Contamination Comparison Between Cotton Pellet and Polytetrafluoroethylene Tape Endodontic Spacers: A Systematic Review

This systematic review compares polytetrafluoroethylene tape and cotton pellet when used as endodontic spacers underneath provisional restorations. The review followed the PRISMA guidelines and was registered in the PROSPERO database (CRD42020176555). Studies that compared the microbial contamination between polytetrafluoroethylene tape and cotton pellet, when used as spacers, were included. Literature searches of Pubmed, Embase, EBSCOHost Dentistry & Oral Sciences Source, Scopus, and Open Grey databases were conducted from their inception until May 2020 for studies in English or other Latin script languages. Hand searching of reference lists was performed. Three laboratory and three clinical studies were included. The risk of bias of the component studies varied widely. Results from the laboratory studies showed higher bacterial counts for cotton pellets. Results from the clinical studies showed that polytetrafluoroethylene tape was associated with a significantly lower incidence of microbial contamination. Findings were consistent throughout the studies, though the evidence available is scarce and heterogeneous. Polytetrafluoroethylene tape was associated with less microbial contamination when compared with cotton pellets as endodontic spacers and therefore appears to be a more suitable material for the purpose.

Immersive 3D Educational Contents: A Technical Note for Dental Educators

Three-dimensional files featuring patients’ geometry can be obtained through common tools in dental practice, such as an intraoral scanner (IOS) or Cone Beam Computed Tomography (CBCT). The use of 3D files in medical education is promoted, but only few methodologies were reported due to the lack of ease to use and accessible protocols for educators. The aim of this work was to present innovative and accessible methodologies to create 3D files in dental education. The first step requires the definition of the educational outcomes and the situations of interest. The second step relies on the use of IOS and CBCT to digitize the content. The last “post-treatment” steps involve free software for analysis of quality, re-meshing and simplifying the file in accordance with the desired educational activity. Several examples of educational activities using 3D files are illustrated in dental education and discussed. Three-dimensional files open up many accessible applications for a dental educator, but further investigations are required to develop collaborative tools and prevent educational inequalities between establishments.

The accuracy of electronic apex locators for determining working length: An in vitro study with artificial teeth

This study aimed to determine the accuracy of four electronic apex locators (EALs) (I-Root, Propex Pixi, Novapex and Bassi iRoot Apex), using artificial mandibular and maxillary permanent molars. The root length (RL) from 40 artificial teeth was initially determined with Kerr hand files. Then, the electronic RL were obtained for the same root canals with each EAL, and the results were compared with those obtained using hand files. The accuracy of the EALs was determined through analysis of the divergences observed in relation to the lengths obtained with files. All EALs were effective for determining the RL in the artificial teeth, showing results similar to those obtained by hand. The Bassi iRoot Apex had higher accuracy (96.7%) than the Propex Pixi (89.1%) and Novapex (85.8%) (P < 0.05). Based on the results, all EALs tested had a similar performance, and artificial teeth may be used to determine the accuracy of these devices.

Perception of a modular 3D print model in undergraduate endodontic education

AIM

To evaluate a modular 3D print training dental model with embedded human teeth and electronic working length determination for undergraduate endodontic education.

METHODOLOGY

Cone-beam volume tomography data of a human skull were transferred into stereolithographic (STL) data, and a customizable modular 3D print model with individually removable sextants and teeth was generated for the use in commercially available phantom heads. Each of sixty-eight students performed a complete root canal treatment on an extracted human tooth. Working lengths were determined with electronic apex locators (EAL) and verified radiographically. Subsequently, an evaluation was carried out with regard to the difficulty of the working steps access cavity preparation, working length determination, root canal preparation/irrigation and canal filling, and these steps were compared to commonly used benchtop models. Additionally, the agreement of electronic and radiographic working length determination was assessed and analysed statistically with the chi-square test.

RESULTS

A total of 68 teeth (20 incisors, 26 premolars and 22 molars) with 127 root canals were treated. In total, 87% of the students considered the modular 3D print model considerably more demanding than the conventional benchtop model. Overall, 96% felt better prepared for the clinical situation, 92% felt markedly reduced stress levels during endodontic practice in the subsequent clinical courses, and 93% of the students suggested the model should be used in future preclinical endodontic training. The preradiographic use of EAL resulted in 85% of the cases having radiographically acceptable working length determination within 0-2 mm from the radiographic apex. Readings more than 2 mm from the apex or beyond were significantly more common in molars than in premolars and incisors (P < 0.05).

CONCLUSIONS

The vast majority of students rated the modular 3D print training model positively despite it being more demanding. They also recommended its use in preclinical teaching and training. The model allowed a more realistic simulation of the clinical situation with a simultaneous use of EALs and led to reduced stress levels in endodontic treatment in the subsequent clinical courses.

Difficulty levels of extracted human teeth used for pre-clinical training in endodontics in an Australian dental school

This study aimed to determine the difficulty level of extracted teeth treated by undergraduate students for pre-clinical endodontic training. Two independent observers assessed a consecutive sample of 1000 periapical radiographs of extracted teeth used in endodontic pre-clinical training. Chi-square test was used to evaluate the adjustment of the distribution, and inter- and intra-examiner agreement were calculated. Minimal, moderate and high difficulty teeth represented 23.1%, 52.1% and 24.8%, respectively. The presence of curvature was the most common grading factor, with 'moderate curvature' reported in 28.7%, and 'extreme curvature' reported in 15.6% of the sample. A difference in the distribution of frequencies was found, favouring the moderate category (P < 0.001). The inter- and intra-examiner strength of agreement were 0.78 and 0.86, respectively. More than 50% of the teeth were categorised as moderate complexity. Almost one-quarter of the total sample, in particular molars, was classified as high complexity, thus unsuitable for undergraduate pre-clinical training.