An evaluation of a teaching aid in endodontics

Students' perception of three-dimensionally printed teeth in endodontic training

INTRODUCTION

In endodontic education, there is a need for thorough training prior to students embarking on clinical treatment. The aim of this study was to use three-dimensional printing technology to create a new model and to compare its suitability for training purposes with resin blocks and extracted teeth.

MATERIALS AND METHODS

Multi-jet-modelling (MJM) produced the 3D model replicating a common difficulty in root-canal morphology. An evaluation study comprising 88 students was run in the sixth semester (summer 2018 and winter 2018/2019). A new questionnaire assessed students' perception of training models and educational environment. Welch's t-test analysed significant differences.

RESULTS

The most pronounced differences between models were noted when rating material hardness, radiopacity, root-canal configuration and suitability for practising. Students estimated their learning outcome as greater with 3D-printed teeth compared to resin blocks. Three-dimensionally printed teeth received significantly lower ratings with regard to enthusiasm, the learning of fine motor skills and spatial awareness, when compared to human teeth (p ≤ .001). However, 3D-printed teeth were appreciated for additional benefits, such as their cleanliness, availability and standardisation of training opportunities with complex root-canal configurations.

CONCLUSION

Students preferred extracted human teeth to 3D-printed teeth with respect to their physical characteristics and training experience. However, educational advantages may compensate for the shortcomings. The new questionnaire proved both adequate and accurate to assess the models and educational environment in endodontic training. The new 3D-printed teeth enhanced the learning opportunities.

Three-Dimensional tooth models for better teaching and treatment outcomes

INTRODUCTION

The aim of this study was to fabricate 3-Dimensional (3D) tooth models to overcome procedural errors that occur during treatment and to improve endodontic management of teeth with complex pulp morphology and dental anomalies.

MATERIALS AND METHODS

Three natural teeth were used to fabricate resinous tooth models (n = 90) and 90 natural teeth were used during root canal treatment. Models were fabricated from 1 mandibular canine (n = 30) and 2 maxillary molars (n = 60). Natural teeth were 30 mandibular canines, 30 mandibular molars and 30 maxillary molars.

RESULTS

Natural teeth and opaque resin models were significantly better than the clear resin models during access preparation (p = .003). In addition, the clear resin models were significantly better than the natural teeth and opaque resin models during shaping, obturation and as an educational tool (p < .001, p < .001 and p < .001 respectively).

CONCLUSIONS

Although it takes more time and effort to produce 3D (3D) tooth models from each natural tooth used in the study, it can give more accurate results during evaluation.

Multi-kingdom microbiota analyses identify bacterial-fungal interactions and biomarkers of colorectal cancer across cohorts

Despite recent progress in our understanding of the association between the gut microbiome and colorectal cancer (CRC), multi-kingdom gut microbiome dysbiosis in CRC across cohorts is unexplored. We investigated four-kingdom microbiota alterations using CRC metagenomic datasets of 1,368 samples from 8 distinct geographical cohorts. Integrated analysis identified 20 archaeal, 27 bacterial, 20 fungal and 21 viral species for each single-kingdom diagnostic model. However, our data revealed superior diagnostic accuracy for models constructed with multi-kingdom markers, in particular the addition of fungal species. Specifically, 16 multi-kingdom markers including 11 bacterial, 4 fungal and 1 archaeal feature, achieved good performance in diagnosing patients with CRC (area under the receiver operating characteristic curve (AUROC) = 0.83) and maintained accuracy across 3 independent cohorts. Coabundance analysis of the ecological network revealed associations between bacterial and fungal species, such as Talaromyces islandicus and Clostridium saccharobutylicum. Using metagenome shotgun sequencing data, the predictive power of the microbial functional potential was explored and elevated D-amino acid metabolism and butanoate metabolism were observed in CRC. Interestingly, the diagnostic model based on functional EggNOG genes achieved high accuracy (AUROC = 0.86). Collectively, our findings uncovered CRC-associated microbiota common across cohorts and demonstrate the applicability of multi-kingdom and functional markers as CRC diagnostic tools and, potentially, as therapeutic targets for the treatment of CRC.

Evaluation of new endodontic tooth models in clinical education from the perspective of students and demonstrators

BACKGROUND

The quality of root canal treatments performed by undergraduate students is often unsatisfactory questioning the current methods of teaching. Based on treatment errors made by students participating the endodontic courses at RWTH Aachen University (Germany), new radiopaque artificial root canal treatment models (DRSK RCT; incisor, premolar, molar) were designed and developed. The aim of the study was to evaluate these models by groups of students and demonstrators.

METHODS

A total number of 60 students and seven demonstrators from a single institution (RWTH Aachen) participated in this study. They performed endodontic treatments on either initial versions of the DRSK RCT or modified versions. The initial versions were evaluated by students (n = 25) and demonstrators (n = 7). The obtained questionnaire was conducted as 7-point Likert-Scale covering the topics material properties, feeling while performing exercises and perception of its closeness to reality via 19 items (students) and 21 items (demonstrators). According to the evaluations several alterations were applied to the DRSK RCT, the whole study was repeated and evaluated by different students (n = 35) and the same demonstrators (n = 7). Additionally, the demonstrators blindly evaluated the quality of root canal treatments performed by the students (n = 35) on the modified DRSK RCT. Comparisons between the initial versions and the modified versions were calculated using Chi-squared tests.

RESULTS

Students as well as demonstrators positively evaluated both variants of the DRSK RCT with especially high ratings in the overall evaluation. Students' rating of the pulp anatomy significantly increased from 5.4 ± 1.1 (mean ± SD) to 5.9 ± 0.9 (mean ± SD; p < 0.05) for the modified model. Likewise, students felt that the ability to flare root canals improved after alterations have been applied. Ratings significantly increased from 4.8 ± 1.6 (mean ± SD) to 5.6 ± 1.0 (mean ± SD; p < 0.05).

CONCLUSION

The results indicate that the DRSK RCT is a promising candidate to be used as an alternative to extracted teeth or as an additional tool for improving dental education. However, some limitations of our analysis have to be considered.

An Update on Root Canal Preparation Techniques and How to Avoid Procedural Errors in Endodontics

Background:

Effective root canal treatment involves cleaning and shaping root canals using a range of instrumentation procedures and techniques. The aim of this review was to provide an update on root canal hand instrumentation techniques and how to overcome iatrogenic errors.

Methods:

A comprehensive search was carried out using multiple databases, PubMed, Medline, Google scholar, and Scopus, to identify relevant studies addressing the objective of this study and to summarize the current evidence to readers. Keywords, i.e., endodontics, root canal preparation, hand instrumentation, techniques and procedural errors, as well as, MeSH terms, i.e. “endodontics”, “instrumentation”, “root canal preparation” were used to conduct our comprehensive search.

Results:

The hybrid technique is a commonly-used approach that combines the benefits of both the crown-down and step-back techniques and was reported to be one of the best techniques to produce an optimal root canal preparation outcome. Hand-instrument manipulation using the balanced forced technique is also favoured as it rapidly and safely permits removal of canal contents allowing irrigants and medications to reach deep inside canal spaces.

Conclusion:

The use of hand files is still recommended for initial canal negotiation and preparation and is essential for the correction of procedural errors. This study provided an update on several hand instrumentation techniques commonly used in endodontics. The correct and safe application of these techniques can prevent iatrogenic procedural errors from occurring which optimizes the quality of treatment outcome.

How to Improve Fine Motor Skill Learning in Dentistry

Introduction

Restorative dental treatment is a complex task involving various procedures which require the development and integration of both theoretical knowledge and fine motor skills. It aims to provide the theoretical background and role of key factors in learning these skills.

Materials and Methods

The following electronic databases were searched to identify relevant articles to our topic: PubMed, Medline, Google Scholar, and Scopus. Generic keywords, that is, factors, fine, performance, and dentistry, and MeSH terms, that is, "learning," "instruction," "patient simulation," "motor skills," "perception," "tactile," "neurophysiology," and "working memory" were used to conduct our comprehensive search. Results and Conclusions. Several techniques are used in performing different restorative procedures in dentistry, that is, root canal preparation, root planning, and minor oral surgery procedures. Mastering these techniques requires a good understanding of the underpinning cognitive, sensory, and neuromuscular processes. Factors including the amount and timing of instructions provided, cognitive abilities, and practice schedule of learning trials may have significant implications on the design of fine motor skill learning exercises.

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

AIM

To compare the educational outcomes using artificial teeth versus extracted teeth for pre-clinical endodontic training.

DATA SOURCES

Literature searches of PubMed, Scopus, Cochrane Library, Trip Database, Web of Science and Open Grey databases were conducted from their inception until November 2018 with no language restriction. Hand searching of most likely relevant journals was performed. The review followed the PRISMA guidelines.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS AND INTERVENTIONS

Studies that compared pre-clinical endodontic training using extracted teeth and artificial teeth were included.

STUDY APPRAISAL AND SYNTHESIS METHODS

The quality of included studies was appraised by Joanna Briggs Institute Critical Appraisal tools. The findings were tabulated and summarized according to their outcomes with distinct narrative syntheses.

RESULTS

Five studies were included. The component studies included 359 operators in total, mainly consisting of undergraduate students (97%, n = 349) and 10 endodontists (3%). Forty-seven per cent (n = 170) operated on artificial teeth only, whilst 19% (n = 67) worked primarily on extracted teeth, with the final treatment outcome being evaluated by independent observers using objective criteria. Operators in two studies (34%, n = 122) used both artificial teeth and ET and compared their experiences in surveys. Regarding technical outcomes, no significant differences between training with artificial teeth and extracted teeth were found, but the performance tended to be better in artificial teeth than extracted teeth. Operators trained solely on artificial teeth appeared to be adequately educated for subsequent root canal treatment (RCT) in the clinical setting.

LIMITATIONS

Due to the scarcity of research on the topic overall, and the methodological variation between the studies, it was not possible to perform a quantitative analysis (meta-analysis).

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

Based on the available evidence, the use of artificial teeth for pre-clinical endodontic training achieved similar educational outcomes compared to extracted teeth. However, the experiences reported by the operators diverged. Further studies assessing other artificial teeth available in the market testing other RCT procedures are necessary.

A novel anatomical ceramic root canal simulator for endodontic training

INTRODUCTION

Endodontic therapy is often complicated and technically demanding. The aim of this study was to develop a reproducible biomimetic root canal model for pre-clinical and postgraduate endodontic training.

MATERIAL AND METHODS

A specific ceramic shaping technique (3D printing and slip casting of a root canal mould) was developed to reproduce canal systems with the desired shape and complexity using a microporous hydroxyapatite (HAp)-based matrix. The microstructural morphology, pore size and porosity, as well as the Vickers microhardness of the ceramic simulators (CS) were assessed and were compared with natural dentin and commercial resin blocks. The reproducibility of the root canal shapes was assessed using the Dice-Sørensen similarity index. Endodontic treatments, from refitting the access cavity to obturation, were performed on the CS. Each step was controlled by radiography.

RESULTS

Many properties of the CS were similar to those of natural dental roots, including the mineral component (HAp), porosity (20%, porous CS), pore size (3.4 ± 2.6 μm) and hardness (120.3 ± 18.4 HV).

DISCUSSION

We showed that it is possible to reproduce the radio-opacity of a tooth and variations in root canal morphology. The endodontic treatments confirmed that the CS provided good tactile sensation during instrumentation and displayed suitable radiological behaviour.

CONCLUSIONS

This novel anatomic root canal simulator is well suited for training undergraduate and postgraduate students in endodontic procedures.

Periapical actinomycosis: report of a case and review of the literature

This case of periapical actinomycosis presented the clinical picture of chronic periapical inflammation. The diagnosis was based on the histological examination of the periapical lesions suggesting the necessity for routine histological examination. Although root canals provide a primary port of entry the Actinomyces organisms into the periapical tissue, periapical actinomycosis, is considered extremely rare. This may be due to the omission of routine histological examination of periapical lesions and the clinical behavior of the disease. The large number of cases reported during the last decade indicates that periapical actinomycosis is more frequent than what it is believed and this is important in the daily dental practice.