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39056915_p49
|
39056915
|
sec[3]/p[0]
|
4. Discussion
| 4.121094 |
biomedical
|
Study
|
[
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[
0.9990234375,
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In this work, we formulated and analyzed the eSPA-Markov algorithm, which expands the family of Entropic AI methodologies to perform learning on ordered data, by addition of a regularization term that biases the solution to have “smooth” transitions between the clusters—where “smoothness” is understood in the sense of the closeness to the latent trajectories of an underlying Markov process. The Markovian smoothness in the learning procedure is enforced through an additional regularization term, which allows applying different forms of priors on the latent Markovian process, given in terms of the Markovian transition matrix P . For example, by selecting the prior matrix P as an identity matrix, we can enforce persistence/metastability of the latent process.
|
[
"Davide Bassetti",
"Lukáš Pospíšil",
"Illia Horenko"
] |
https://doi.org/10.3390/e26070553
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056915_p50
|
39056915
|
sec[3]/p[1]
|
4. Discussion
| 4.089844 |
biomedical
|
Study
|
[
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[
0.9990234375,
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We illustrated how using the one-dimensional negative log-likelihood as the loss function allows us to distinguish between regimes with overlapping means and differences in variance. We simultaneously solve the problems of learning the segmentation patterns as well as the entropy-optimal feature space discretizations and Bayesian classification rules, via iterative monotonic minimization of the constrained functional (12). In Theorems 1 and 2, we provided estimates of the computational cost scaling and conditions for existence and uniqueness of the solutions of the resulting problem.
|
[
"Davide Bassetti",
"Lukáš Pospíšil",
"Illia Horenko"
] |
https://doi.org/10.3390/e26070553
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999999 |
39056915_p51
|
39056915
|
sec[3]/p[2]
|
4. Discussion
| 3.654297 |
biomedical
|
Study
|
[
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[
0.9921875,
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The performance of this algorithm on toy examples with time evolution was compared to state-of-the-art machine learning, deep learning, and signal processing tools, including neural networks that feature convolutional layers and LSTM layers, as well as with the preprocessing using wavelet transform. With the provided examples, we highlight how the proposed eSPA-Markov approach not only allows classification of data in spite of elevated noise but it does so with a competitive computational performance, and on high-dimensional data.
|
[
"Davide Bassetti",
"Lukáš Pospíšil",
"Illia Horenko"
] |
https://doi.org/10.3390/e26070553
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056915_p52
|
39056915
|
sec[3]/p[3]
|
4. Discussion
| 4.101563 |
biomedical
|
Study
|
[
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0.007671356201171875
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[
0.9990234375,
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In order to obtain a fair and thorough comparison between the different methods, we first focused on univariate data, in which successful prediction does not require the identification of the relevant dimensions. Please note that the dimensionality reduction step is explicitly included in our methodology but is not explicitly available in the other considered methods—so, this should give an advantage to the selected common tools in one-dimensional applications. We compared the performances while varying the signal-to-noise level and the number of available data points for training (T). As can be seen from Figure 2 and Figure 3 , the performance of common tools deteriorates quickly when approaching the small noisy data scenario, whereas eSPA-Markov outperforms the competition in this situation. Limited training data represent a challenging condition, as can be seen when the available data points for training are 250 . eSPA-Markov consistently obtained higher scores than every other method, as can be seen particularly for σ -ratios of 1.5 with T being 1000 or 2500, where the proposed method is the only one out of the compared methods that could consistently reach an AUC close to 1. In terms of computational cost, one observes (i) an increase in cost for all the considered methods for growing data statistics, and (ii) that the cost scaling of eSPA-Markov is comparable to that of SVM, which is traditionally appreciated for its advantageous cost scaling, in situations with restricted sample sizes and elevated dimensionality.
|
[
"Davide Bassetti",
"Lukáš Pospíšil",
"Illia Horenko"
] |
https://doi.org/10.3390/e26070553
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056915_p53
|
39056915
|
sec[3]/p[4]
|
4. Discussion
| 4.148438 |
biomedical
|
Study
|
[
0.96142578125,
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0.037841796875
] |
[
0.9970703125,
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0.00005418062210083008
] |
As shown in Figure 4 and Figure 5 , the performance of common tools drops drastically with the addition of a modest number of non-informative dimensions. Indeed, despite the relatively small difference from the previous comparison, adding non-informative data dimensions is sufficient to impair the performance of the considered deep learning methods that fail to produce good results on the testing set. This is a manifestation of the well known problem of overfitting, as the networks achieve perfect prediction on the training split, but are not able to generalize their performance when using unseen test data. This issue is due to the fact that increasing the number of dimensions requires the use of more data to form accurate decision boundaries . In fact, for all of the methods, larger training datasets allowed better performance on the test data; for example, CNN-LSTM was only able to provide valuable predictions for the larger dataset sizes we evaluated. Providing the wavelet-transformed data to the CNN-LSTM network (i.e., in the “w-CNN-LSTM” model) could partially mitigate this issue and allow a better performance on small datasets, in a comparable way to random forest models. However, the performance of eSPA-Markov was shown to always be superior to the other models taken into account, and it was able to consistently obtain better predictions for the whole range of training data sizes. Moreover, the computational cost of training eSPA-Markov was one order of magnitude lower than that of RF and two orders of magnitude lower than that of w-CNN-LSTM in the low-data-availability condition. Summarizing, eSPA-Markov displayed a competitive performance, outperforming considered common tools in terms of quality of prediction, training cost, and scalability.
|
[
"Davide Bassetti",
"Lukáš Pospíšil",
"Illia Horenko"
] |
https://doi.org/10.3390/e26070553
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056915_p54
|
39056915
|
sec[3]/p[5]
|
4. Discussion
| 4.121094 |
biomedical
|
Study
|
[
0.98974609375,
0.0003314018249511719,
0.00975799560546875
] |
[
0.9990234375,
0.0003962516784667969,
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0.00003504753112792969
] |
Figure 6 and Figure 7 further illustrated the performance in a situation of increasingly “small” data. It was possible to observe how the performance of deep learning techniques as well as of SVM quickly degraded with the increasing number of dimensions. It is important to note that the cost of SVM being very low on the datasets with higher dimensionality was negated by the poor predictive performance on these datasets. As for the previous example, random forest was the only method besides of the eSPA-Markov that could provide good predictive performance, but with more than one order of magnitude larger computational costs across all examined feature sizes. These results do not imply that larger neuronal networks (or networks with different architectures) could not perform better than the ones selected here, but finding an optimal network architecture and hyperparameterization is an NP-hard task. In contrast, finding the optimal values for four gridded hyperparameters (namely, K , ε C L , ε E and ε L ) scales polynomially (as the polynomial of degree 4, when checking all possible hyperparameter combinations), with the cost of every hyperparameter combination scaling linearly (according to the Theorem 1).
|
[
"Davide Bassetti",
"Lukáš Pospíšil",
"Illia Horenko"
] |
https://doi.org/10.3390/e26070553
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056915_p55
|
39056915
|
sec[3]/p[6]
|
4. Discussion
| 4.257813 |
biomedical
|
Study
|
[
0.99951171875,
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[
0.998046875,
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0.0013303756713867188,
0.00009369850158691406
] |
We also demonstrated the possibility of using the proposed framework in a direct one-shot way, in the case when there exists a bijective mapping between the label probabilities and the cluster affiliations. We showcased the efficacy of this task on a toy model, based on a real-life application in molecular biology/bioinformatics—the denoising and classification of sequencing data obtained with the Oxford Nanopore technology. Scaling this approach up to real datasets of this type, which would involve a much larger number of possible latent states K (due to the higher number of bases, also considering epigenetics modifications, and k-mer length) represents an interesting future application of the presented methodology. Another potential use case is that of noisy data series having different notions of ordering—not necessarily being the ordering in time. For instance, in the field of molecular biology, measurements from cells could be ordered along the developmental trajectory of their differentiation, and if the samples cannot be measured with an explicit ordering, an approximation can be inferred from the data by using the permutation finding the smoothest reordering . Additionally, any arbitrary graph could be used to formulate the respective Markovian prior P —imposing a notion of “neighborhood” and “smoothness” that is relevant for the problem at hand. As an example, eSPA-Markov could be used to obtain smooth reconstructions simultaneously in time and space, with application to images and videos. Thus, this technique can potentially match for supervised classification of the results obtained by its unsupervised variant, which was shown to outperform state-of-the-art methods in denoising extremely low radiation and high-noise computer tomography data .
|
[
"Davide Bassetti",
"Lukáš Pospíšil",
"Illia Horenko"
] |
https://doi.org/10.3390/e26070553
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056986_p0
|
39056986
|
sec[0]/p[0]
|
1. Introduction
| 3.775391 |
biomedical
|
Other
|
[
0.9912109375,
0.00255584716796875,
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[
0.059539794921875,
0.853515625,
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0.0010662078857421875
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In recent years, there have been significant changes in dental education within German dental schools, particularly with the incorporation of digital dentistry technologies into the curriculum to meet the amendment of the federal license regulation (ZApprO) that came into effect in 2021. These changes have prompted revisions in content and teaching methods for both pre-clinical and clinical courses, still aiming to thoroughly prepare students for patient treatments as a practice-ready dentist after graduation . Digital innovations in terms of a “Dentistry 4.0” include technologies such as machine learning, augmented and virtual reality (AR and VR), as well as 3D printing, which are going to become an integral part of modern teaching methods in the long run . Today, digital technologies, including intraoral scanning, computer-aided designing (CAD), and in-house production through methods like 3D printing, have become integral to preclinical and clinical training already .
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056986_p1
|
39056986
|
sec[0]/p[1]
|
1. Introduction
| 1.96582 |
biomedical
|
Other
|
[
0.970703125,
0.0083465576171875,
0.02099609375
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[
0.010955810546875,
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] |
Nevertheless, acquiring manual skills to handle preparations for direct and indirect restorations is (and will be) still a major topic.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056986_p2
|
39056986
|
sec[0]/p[2]
|
1. Introduction
| 3.884766 |
biomedical
|
Other
|
[
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0.0021343231201171875,
0.0008378028869628906
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[
0.37744140625,
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Traditionally, preparation training occurs on simulation units using standardized models in an ideal, healthy, and eugnathic—but this way unrealistic—setting. The teeth in these models are exchangeable and made from a hard plastic material, lacking the realism of tilted, rotated, narrow positioned, elongated, or periodontally damaged teeth with diverging insertion directions . Although these ideal models are commonly used for preparation training just before patient treatment, experiences in clinical courses suggest that preparing teeth in a reduced dentition differ significantly from those of a healthy and full dentition. The scope of clinical prosthodontic treatments in German universities ranges from reduced dentition to be provided with telescopic dentures up to multi-unit fixed dental prostheses (FDP) .
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056986_p3
|
39056986
|
sec[0]/p[3]
|
1. Introduction
| 2.160156 |
biomedical
|
Other
|
[
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[
0.07122802734375,
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0.0033512115478515625
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Own experiences in these clinical courses showed that the preparation of teeth in a reduced dentition, for example, for double crowns, poses greater challenges for the students compared to three-unit FDPs, for instance.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056986_p4
|
39056986
|
sec[0]/p[4]
|
1. Introduction
| 2.046875 |
biomedical
|
Other
|
[
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[
0.007427215576171875,
0.99072265625,
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0.0007305145263671875
] |
Various companies offer models and teeth for simulating endodontic or surgical procedures. In line with the above-mentioned implementation of CAD and additive and subtractive manufacturing into the curriculum, these technologies help to facilitate individual objects for teaching. This way, the necessity of extracted human teeth is lost when it comes to dentition .
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056986_p5
|
39056986
|
sec[0]/p[5]
|
1. Introduction
| 3.935547 |
biomedical
|
Review
|
[
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[
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In particular, Peters et al. developed a special 3D-printed tooth replica instead of natural extracted teeth in an attempt to improve students’ skills in root canal treatments. However, they did not find significant improvement and recommended further improvements in resin materials to better simulate natural enamel and dentine properties . Höhne et al. designed 3D-printed teeth with varied layering and material properties to enhance students’ preparation of technique training . In 2020, Hanisch et al. explored the use of individualized 3D-printed surgical training models to simulate apicoectomy based on real patient data. Compared to commercial typodont models, the 3D-printed models provide a more realistic simulation . Reymus et al.’s working group developed and evaluated an interdisciplinary single 3D-printed model suitable for root canal treatment, post insertion, and implant insertion. In a survey, students rated the treatments on these models as realistic and comparable to real patient situations .
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999995 |
39056986_p6
|
39056986
|
sec[0]/p[6]
|
1. Introduction
| 4.117188 |
biomedical
|
Study
|
[
0.998046875,
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] |
[
0.99853515625,
0.00127410888671875,
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0.00016641616821289062
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The aim of the present study was to simulate the individual prosthetic treatment cases in dental simulation units with phantom heads (KaVo-Kerr Comp., Biberach, Germany) in order to better prepare students for their patient treatments in undergraduate clinical courses. These measures could improve dental education, enhance students’ confidence and skills in complex tooth preparations, and make patient treatment more time efficient. Thus, students can be made aware of potential problems in advance, allowing them to prevent complications during actual patient treatment. Therefore, a workflow should be established that allows for the in-house manufacturing of individual patient case models based on the intraoral scan that can be mounted in a standardized phantom head. These 3D-printed models should contain the removable artificial teeth of comparable hardness to standardized phantom teeth (e.g., #ANKA 4-Z, frasaco GmbH., Tettnang, Germany).
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999995 |
39056986_p7
|
39056986
|
sec[0]/p[7]
|
1. Introduction
| 2.035156 |
biomedical
|
Other
|
[
0.7919921875,
0.06494140625,
0.1431884765625
] |
[
0.0093231201171875,
0.98828125,
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0.0011434555053710938
] |
After preparation trainings with these models, the students should share their experiences and give feedback within a questionnaire regarding feasibility and transferability towards the later treated clinical situation.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999999 |
39056986_p8
|
39056986
|
sec[0]/p[8]
|
1. Introduction
| 1.779297 |
biomedical
|
Study
|
[
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[
0.9638671875,
0.03277587890625,
0.002593994140625,
0.0007562637329101562
] |
Thereby, the study did not follow any hypothesis due to its exploratory character towards feasibility.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056986_p9
|
39056986
|
sec[1]/sec[0]/sec[0]/p[0]
|
2.1.1. Mounting Plate for the Phantom Head including Distance Holders
| 4.128906 |
biomedical
|
Study
|
[
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[
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Initially, a plate for mounting the models in a phantom head (#P6/3 Pro, frasaco GmbH, Tettnang, Germany) was designed using construction software (Fusion360, Autodesk Inc., San Rafael, CA, USA). A screw hole was strategically positioned to align with the receptacle in the phantom head, allowing for secure mounting with the screw. The mounting plate, featuring a grid structure on one side, aimed to provide ample support for models to adhere securely. This design was replicated for both upper and lower jaw models. Additionally, the mounting plates included receptacles for four distance holders, simulating the actual position of the upper jaw in relation to the lower jaw . The 3D printing process for both mounting plates and spacers utilized a material extrusion 3D printer MK3S (Prusa Research a.s., Prague, Czech Republic) with a polylactide (PLA) filament (Prusament PLA Vanilla White, Prusa Research a.s.). The average cost of materials per case for mounting parts was EUR 2.37 (2 mounting plates, 4 spacers).
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999995 |
39056986_p10
|
39056986
|
sec[1]/sec[0]/sec[0]/p[1]
|
2.1.1. Mounting Plate for the Phantom Head including Distance Holders
| 1.079102 |
other
|
Other
|
[
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[
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The mounting plate dataset is provided (in an updated/improved version) by the authors for download as an STL file at https://doi.org/10.5281/zenodo.11174653 .
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999995 |
39056986_p11
|
39056986
|
sec[1]/sec[0]/sec[1]/p[0]
|
2.1.2. Jaw Models with Exchangeable Teeth for Preparation
| 4.195313 |
biomedical
|
Study
|
[
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0.00044417381286621094
] |
Each student was asked to acquire a digital intraoral scan (IOS) of their patient using a Medit i500 (Medit, Seoul, Republic of Korea). Subsequently, the scans were exported, and the model design was completed by a consistent operator in Ceramill Mind (Amann Girrbach GmbH, Pforzheim, Germany) on the exocad operating system (exocad GmbH, Darmstadt, Germany). The scan data for the upper jaw, lower jaw, and occlusion were imported into the model creator module of the software. Considering the 40 mm distance between the receptacles of the phantom head, the model height was adjusted to 42 mm. To minimize material waste, scans were manually trimmed, retaining essential structures such as the alveolar ridge and teeth. The specific teeth for preparation were separated from the rest of the model. The exchangeable teeth were selected using the FDI tooth numbering system; afterwards, the software was able to detect the correct margin line of most of these teeth. If the margin line was not detected automatically, the line was corrected manually by determining additional points. Parameters for the model dies, such as pin height (1.5 mm), die shape (10°), extrusion of preparation margin (0 mm), horizontal shaft gap (0 mm) or vertical shaft gap (0.2 mm), were fine-tuned during initial trials to ensure good friction. The final step involved uploading the mounting plates to the software as attachments in the correct three-dimensional orientation (plate-to-plate distance 40 mm) and subtracting from the models. This process resulted in the negative form of the grid on the bottom side of the models .
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999999 |
39056986_p12
|
39056986
|
sec[1]/sec[0]/sec[1]/p[1]
|
2.1.2. Jaw Models with Exchangeable Teeth for Preparation
| 4.097656 |
biomedical
|
Study
|
[
0.99658203125,
0.0005650520324707031,
0.0030269622802734375
] |
[
0.98779296875,
0.0115814208984375,
0.0004820823669433594,
0.00011539459228515625
] |
The model bases and removable teeth were exported in a standard tessellation language (STL) file format. Due to differing requirements for the model base and teeth, they were produced using different materials in the stereolithography (SLA) 3D printer Form 3B (Formlabs Inc., Somerville, MA, USA). The model bases (average cost of materials per case for models: EUR 2.70–3.30 (1 upper jaw model, 1 lower jaw model)) were printed in Model Resin V3 (Formlabs Inc.), while the removable teeth (average cost of materials per case for teeth: EUR 0.30–8.40 (1–8 exchangeable teeth, different type of teeth)) were printed in Rigid 10K Resin V1 (Formlabs Inc.) to closely mimic the feel and preparability of natural teeth. This also allowed students the flexibility to print and replace a tooth for preparation multiple times. Post-processing adhered to manufacturer instructions, involving washing (models for 10 min and teeth two times for 10 min in Form Wash (Formlabs Inc.)) and curing (models for 5 min at 60 °C and teeth for 60 min at 70 °C in Form Cure (Formlabs Inc.)) for the respective materials.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056986_p13
|
39056986
|
sec[1]/sec[0]/sec[2]/p[0]
|
2.1.3. Assembly of the Training Model
| 3.595703 |
biomedical
|
Other
|
[
0.98583984375,
0.010162353515625,
0.00382232666015625
] |
[
0.3125,
0.6826171875,
0.0009832382202148438,
0.0038585662841796875
] |
Removable teeth were inserted into the model base, and the model base was then affixed to the mounting plate following the prepared grid structure. Distance holders were placed, ensuring that each model base fit into only one position on the mounting plate. Since the IOS included the digital recording of the jaw relation, the spacers’ attachment aimed to ensure the accurate positioning of the occlusion plane . Finally, the mounting plates with models and removable teeth were secured in the phantom head using screws on each side .
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056986_p14
|
39056986
|
sec[1]/sec[1]/p[0]
|
2.2. Students Preparation and Feedback
| 3.996094 |
biomedical
|
Study
|
[
0.9736328125,
0.024261474609375,
0.002105712890625
] |
[
0.71240234375,
0.2802734375,
0.0019083023071289062,
0.005664825439453125
] |
Each 9th semester student, previously trained on conventional frasaco preparation teeth (standard teeth ANA-4 Z, frasaco GmbH, Tettnang, Germany) in preclinical courses, was tasked with practicing preparation on the removable teeth of the individualized 3D-printed models. This practice session required planning and execution according to the associated patient’s treatment plan. Subsequently, each student showcased the preparation on the model to an assistant doctor for evaluation. Upon successful preparation of the individualized 3D-printed teeth, students replicated the same preparation on their respective patients. If the treatment plan had changed between teeth preparation and patient preparation, or if the in vivo situation required a different type of preparation, adjustments were made accordingly. Conventional rotating instruments, such as diamond-coated dental burrs in various shapes (e.g., torpedo, round head bur, bud, etc.), were used for preparations under constant water cooling of 50 mL per minute.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056986_p15
|
39056986
|
sec[1]/sec[1]/sec[0]/p[0]
|
Questionnaire
| 1.569336 |
biomedical
|
Study
|
[
0.86572265625,
0.006443023681640625,
0.1278076171875
] |
[
0.7861328125,
0.2015380859375,
0.01012420654296875,
0.002246856689453125
] |
A summary of all questions in the questionnaire is shown in Table 1 .
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056986_p16
|
39056986
|
sec[1]/sec[1]/sec[0]/p[1]
|
Questionnaire
| 2.595703 |
biomedical
|
Study
|
[
0.98974609375,
0.0028743743896484375,
0.007404327392578125
] |
[
0.98828125,
0.0113983154296875,
0.0002491474151611328,
0.0002925395965576172
] |
Following preparation on conventional frasaco teeth during preclinical training, 3D-printed teeth, and patients’ teeth, all students were asked to complete a questionnaire assessing the effectiveness of preliminary preparations. Participants received instructions on completing the questionnaire, and each questionnaire was assigned an anonymized pseudonym created by the participants themselves. Pseudonyms comprised initial letters or numbers from categories such as parental names, birthdays, places of birth, and personal characteristics.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056986_p17
|
39056986
|
sec[1]/sec[1]/sec[0]/p[2]
|
Questionnaire
| 2.107422 |
biomedical
|
Study
|
[
0.8642578125,
0.0024814605712890625,
0.133056640625
] |
[
0.783203125,
0.2149658203125,
0.0013418197631835938,
0.0006761550903320312
] |
The questionnaire consisted of 11 questions. The first three questions sought general information about the performed treatment. The responses to the seven following questions were formulated as a Likert scale with seven increments. An odd number of increments (7) was chosen because a neutral response in the middle of the scale, which neither favors one side nor the other, was considered necessary. This allowed each participant to choose either one clear statement on the poles, a neutral position in the middle, or two gradations in between. The questions should reflect students’ opinions on the preparation of 3D-printed models compared to frasaco models. A free-text comment was optional at the end of the questionnaire.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056986_p18
|
39056986
|
sec[1]/sec[1]/sec[0]/p[3]
|
Questionnaire
| 2.335938 |
biomedical
|
Study
|
[
0.99072265625,
0.0007696151733398438,
0.00836944580078125
] |
[
0.97802734375,
0.02142333984375,
0.0004818439483642578,
0.00029587745666503906
] |
Discrete responses were entered into a data table for descriptive statistics using JMP software package (15.2, SAS Corp., Cary, NC, USA); the free text feedback was analyzed qualitatively by inductive categorization.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056986_p19
|
39056986
|
sec[2]/p[0]
|
3. Results
| 2.126953 |
biomedical
|
Study
|
[
0.984375,
0.002819061279296875,
0.01299285888671875
] |
[
0.99560546875,
0.0037384033203125,
0.00027251243591308594,
0.00027370452880859375
] |
The study was conducted with one semester cohort of whom all students (n = 27) returned their questionnaires. Two participants treated two patients each, resulting in a total of n = 29 datasets available for evaluation. Participants adhered to the pseudonym creation rules, providing legible entries on the questionnaires. All questionnaires were completed clearly and legibly, with no additional incomplete or excluded datasets.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056986_p20
|
39056986
|
sec[2]/sec[0]/p[0]
|
Datasets
| 2.505859 |
biomedical
|
Study
|
[
0.99169921875,
0.0028839111328125,
0.0055694580078125
] |
[
0.98095703125,
0.0182647705078125,
0.0003409385681152344,
0.000518798828125
] |
A total of 11 models for FDPs and 18 models for CFRDP treatments were fabricated, prepared, and evaluated by the participants. For FDP, two were in the lower, five in the upper, and three in both jaws. For CFRDP, five were in the mandible, seven in the maxilla, and seven in both jaws .
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056986_p21
|
39056986
|
sec[2]/sec[0]/p[1]
|
Datasets
| 2.787109 |
biomedical
|
Study
|
[
0.97705078125,
0.0093231201171875,
0.01340484619140625
] |
[
0.9794921875,
0.019378662109375,
0.0004277229309082031,
0.0005655288696289062
] |
For the second question, more than 29 answers were summarized due to multiple possible responses. In total, 14 students had to remove crowns before treatment, 3 had to remove partial crowns, 9 had to change fillings, and 5 students had to perform a post and core build-up before treatment ( Table 2 ). The final general information about the location of preparation resulted in a total of 67 answers, as multiple responses were possible. In total, 26 students prepared in the dentine, 20 in enamel and 21 in core build-up.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056986_p22
|
39056986
|
sec[2]/sec[0]/p[2]
|
Datasets
| 1.694336 |
biomedical
|
Study
|
[
0.716796875,
0.00269317626953125,
0.28076171875
] |
[
0.8837890625,
0.1126708984375,
0.002758026123046875,
0.0008091926574707031
] |
The distribution of all answers for questions no. 4 to 10 are shown in Figure 3 .
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056986_p23
|
39056986
|
sec[2]/sec[0]/p[3]
|
Datasets
| 2.566406 |
biomedical
|
Study
|
[
0.9921875,
0.0007767677307128906,
0.00714874267578125
] |
[
0.9951171875,
0.00450897216796875,
0.00048470497131347656,
0.00013017654418945312
] |
The fourth question regarding the perception of the preparation exercise on 3D-printed models compared to the commonly used frasaco models ranged from very effective (increment 1) to increment 4, with a mean of 1.89 ± 0.86.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056986_p24
|
39056986
|
sec[2]/sec[0]/p[4]
|
Datasets
| 2.216797 |
biomedical
|
Study
|
[
0.94189453125,
0.00614166259765625,
0.05181884765625
] |
[
0.9609375,
0.038055419921875,
0.0006823539733886719,
0.0004680156707763672
] |
The fifth question assessed how well the exercise prepared students for patient treatment, with possible responses ranging from very good (increment 1) to very bad (increment 6), yielding a mean of 2.48 ± 1.02.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056986_p25
|
39056986
|
sec[2]/sec[0]/p[5]
|
Datasets
| 2.193359 |
biomedical
|
Study
|
[
0.98876953125,
0.00438690185546875,
0.006805419921875
] |
[
0.97412109375,
0.0241546630859375,
0.0006289482116699219,
0.0008559226989746094
] |
The sixth question inquired about the preparability of 3D-printed teeth, with responses ranging from close to the patient (increment 2) to different from the patient situation (increment 5), resulting in a mean of 3.10 ± 1.05.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056986_p26
|
39056986
|
sec[2]/sec[0]/p[6]
|
Datasets
| 2.199219 |
biomedical
|
Study
|
[
0.98876953125,
0.00241851806640625,
0.00858306884765625
] |
[
0.95166015625,
0.046844482421875,
0.0008053779602050781,
0.0008263587951660156
] |
Similar to the previous question, the following one addressed the preparability of frasaco teeth, with responses spanning from close to the patient (increment 2) to different from the patient situation (increment 7), and a mean of 4.93 ± 1.36.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056986_p27
|
39056986
|
sec[2]/sec[0]/p[7]
|
Datasets
| 2.265625 |
biomedical
|
Study
|
[
0.9833984375,
0.0016431808471679688,
0.0149383544921875
] |
[
0.98583984375,
0.01337432861328125,
0.0004868507385253906,
0.000347137451171875
] |
The subsequent question aimed to understand how well the models could be assembled in the phantom head. Responses varied from very good (increment 1) to very bad (increment 7), with a mean of 4.14 ± 1.87.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056986_p28
|
39056986
|
sec[2]/sec[0]/p[8]
|
Datasets
| 1.995117 |
biomedical
|
Study
|
[
0.935546875,
0.0022602081298828125,
0.062255859375
] |
[
0.98193359375,
0.0175323486328125,
0.0004229545593261719,
0.00030040740966796875
] |
The following question assessed whether participants required more supervision compared to the usual preparation exercises on the frasaco model. Answers ranged from yes (increment 2) to no (increment 7), with a mean of 6.10 ± 1.18.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999995 |
39056986_p29
|
39056986
|
sec[2]/sec[0]/p[9]
|
Datasets
| 2.441406 |
biomedical
|
Study
|
[
0.990234375,
0.0030612945556640625,
0.00665283203125
] |
[
0.99169921875,
0.007598876953125,
0.00042128562927246094,
0.00039887428283691406
] |
The final question examined whether the jaw relation of the model corresponded to that in the patient’s mouth. Responses ranged from completely (increment 1) to not at all (increment 7), with a mean of 4.55 ± 1.33.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056986_p30
|
39056986
|
sec[2]/sec[0]/p[10]
|
Datasets
| 3.498047 |
biomedical
|
Study
|
[
0.9873046875,
0.007610321044921875,
0.005252838134765625
] |
[
0.99169921875,
0.007213592529296875,
0.00078582763671875,
0.00028395652770996094
] |
All students (n = 27) provided free-text comments. The answers contain four categories: individuality, proximity to the patient, material, and assembly in the phantom head. In summary, students reported feeling better and more confidently prepared for patient treatment thanks to the individual patient models. The students particularly addressed that tilted and elongated teeth could be better prepared, even though they reported to better assess the amount of substance removal and the path of insertion. Regarding material and assembly in the phantom head, the students agreed that the printed teeth were easier to prepare than the frasaco teeth. However, they demanded improvements to the mounting interface to the phantom heads, because some of the models could not be placed correctly on the mounting plates. The same applies for the distance holders that had to be adjusted for a reliable fit.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056986_p31
|
39056986
|
sec[2]/sec[0]/p[11]
|
Datasets
| 2.195313 |
biomedical
|
Other
|
[
0.94677734375,
0.04046630859375,
0.01280975341796875
] |
[
0.1435546875,
0.833984375,
0.016937255859375,
0.00550079345703125
] |
The identified common opinion highlighted that the efforts involved in the intraoral scan, the production of the individual models, and the practice preparations on the printed models provided worthwhile preparation for clinical patient treatment with increased safety and confidence.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056986_p32
|
39056986
|
sec[3]/p[0]
|
4. Discussion
| 2.119141 |
biomedical
|
Other
|
[
0.9111328125,
0.043121337890625,
0.045928955078125
] |
[
0.435302734375,
0.5537109375,
0.0018138885498046875,
0.00926971435546875
] |
After the initial assembly of the models in the phantom head, it became evident that the correct jaw relation could not always be adequately established. This is also reflected in question no. 10 where a significant number of participants expressed dissatisfaction with the adjustment of the jaw relation or its correspondence with the patient’s actual jaw relation. The distance holders could not be fixed securely in the designated recesses.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999995 |
39056986_p33
|
39056986
|
sec[3]/p[1]
|
4. Discussion
| 3.958984 |
biomedical
|
Study
|
[
0.98828125,
0.003528594970703125,
0.0082855224609375
] |
[
0.75341796875,
0.24267578125,
0.0028476715087890625,
0.0013370513916015625
] |
Consequently, after immediate oral feedback, the sockets needed a fundamental design adjustment. Instead of placing it on the front face of the mounting plate, it was positioned parallel to the grid structure. Consequently, the spacers no longer had a 90° angulation, enhancing the mechanical stability of the bars; this finding is in line with further fine-tuned printing parameters, which are a reliable fit. Moreover, the grid structure on the mounting plate was minimized to reduce printing time and material costs while maintaining the necessary support for the models. These early oral critiques regarding the support structures for the jaw relation and the mounting of the models on the plates were later echoed in the free-text comments. Another option would be to print the model and the mounting plates in one piece. This would make it easier to adapt the individual structures and could improve the adjustment of the jaw relation. However, such an approach would result in higher printing costs.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056986_p34
|
39056986
|
sec[3]/p[2]
|
4. Discussion
| 2.503906 |
biomedical
|
Study
|
[
0.96923828125,
0.00701904296875,
0.0236968994140625
] |
[
0.71923828125,
0.277099609375,
0.002384185791015625,
0.0015010833740234375
] |
Another crucial point would be the comparison of prior preparations on frasaco models with those on a patient-specific/individualized printed model. The preparations on the frasaco model did not replicate the patient’s situation, but rather mirrored a standardized scenario; this was the same condition for all students. Preparation on the patient-individualized model is reasonable at a later point in time of the curriculum; however, both preparation exercises on the phantom are not completely comparable.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056986_p35
|
39056986
|
sec[3]/p[3]
|
4. Discussion
| 2.748047 |
biomedical
|
Other
|
[
0.9853515625,
0.003185272216796875,
0.0115966796875
] |
[
0.4951171875,
0.501953125,
0.00194549560546875,
0.00115966796875
] |
The objective of using 3D-printed removable teeth was to select a material that closely resembles a natural tooth structure, approaching the clinical situation as closely as possible. Further, the preparation could be repeated without a remake of the complete model due to their exchangeability. This aspect is also addressed in the free texts and is positively evaluated regarding the material choice for the printed teeth.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056986_p36
|
39056986
|
sec[3]/p[4]
|
4. Discussion
| 2.345703 |
biomedical
|
Study
|
[
0.9501953125,
0.002658843994140625,
0.047210693359375
] |
[
0.7099609375,
0.28662109375,
0.002872467041015625,
0.0008182525634765625
] |
Responses to questions no. 6 and no. 7, in agreement with the free-text comments, indicated that the preparability of the printed teeth is closer to the patient’s situation than the preparation of frasaco teeth, thus more closely similar to a real situation. Some students even observed that the material properties of the printed teeth were “more comparable to enamel” than the frasaco teeth material. In summary, it can be asserted that the 3D-printed near-patient model represents an improvement in students becoming ready for patient treatment.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056986_p37
|
39056986
|
sec[3]/p[5]
|
4. Discussion
| 3.71875 |
biomedical
|
Study
|
[
0.9951171875,
0.00222015380859375,
0.0026302337646484375
] |
[
0.994140625,
0.004413604736328125,
0.0012197494506835938,
0.00017333030700683594
] |
Even question no. 9 demonstrated that the need for support from a supervising dentist is less for the 3D-printed models than for previous preparation exercises on frasaco models. However, this can be attributed to the fact that students of the study cohort had already undergone frasaco preparation training during their preclinical courses. It is, therefore, not conclusive if the need for support diminishes through practice, irrespective of the model used. Therewith, it must be highlighted that students should be extensively familiar with their patients’ treatment situation, creating a better foundational prerequisite for the preparation session than a scenario lacking clinical background, enhancing students’ self-confidence and potentially leading to better results.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999995 |
39056986_p38
|
39056986
|
sec[3]/p[6]
|
4. Discussion
| 1.844727 |
biomedical
|
Other
|
[
0.7314453125,
0.004108428955078125,
0.264404296875
] |
[
0.03973388671875,
0.958984375,
0.0006227493286132812,
0.0004868507385253906
] |
Nevertheless, the time required to design and fabricate the models, individual teeth, and mounting plates is lacking in our data. Since the students did not handle this process themselves, it is provided by the teaching staff. The goal for upcoming semesters is to simplify the process and delegate a significant portion to the students, which will also train their skills to work with CAD and 3D printing on their own. This starts with assembling the components provided, as printed and supported by online instructions, that shall reduce the time burden for teaching staff.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056986_p39
|
39056986
|
sec[3]/p[7]
|
4. Discussion
| 2.28125 |
biomedical
|
Other
|
[
0.9130859375,
0.004146575927734375,
0.0828857421875
] |
[
0.11346435546875,
0.884765625,
0.0008740425109863281,
0.0007653236389160156
] |
Cost considerations towards printer and material revealed EUR 6 is needed to fabricate all components for both jaws, excluding the exchangeable teeth. As previously mentioned, there was a call for a material of markedly higher quality and price, resulting in approximately EUR 1 per removable tooth. This renders the total cost for this model higher than for a conventionally printed model without removable teeth, but is more sustainable for multiple iterations of training in this situation, even for other students in advance preclinical training, for instance.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056986_p40
|
39056986
|
sec[4]/p[0]
|
5. Conclusions
| 3.96875 |
biomedical
|
Study
|
[
0.99755859375,
0.001880645751953125,
0.0006837844848632812
] |
[
0.96240234375,
0.0110015869140625,
0.0260467529296875,
0.0005664825439453125
] |
The integration of 3D printing technology into dental education demonstrates promising results in addressing key challenges of clinical training. The patient-specific 3D-printed dental models bridging the gap between simulated exercises and actual patient scenarios provide students with a more realistic and tailored preparation experience. This was experienced positively, as expressed in the students’ feedback, apart from the previously mentioned shortcomings in assembly and mounting of the models. The results suggest that this approach contributes to improved confidence and skill development.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056986_p41
|
39056986
|
sec[4]/p[1]
|
5. Conclusions
| 4.019531 |
biomedical
|
Study
|
[
0.9990234375,
0.0007610321044921875,
0.00035953521728515625
] |
[
0.9873046875,
0.0019855499267578125,
0.01025390625,
0.00025153160095214844
] |
The study underlines the potential of 3D printing to enhance dental education, offering a valuable tool for individualized and realistic training in a phantom setting. However, ongoing improvements in material properties and cost-effective approaches are crucial for broader implementation. As technology continues to advance, the integration of 3D printing in dental education holds promise for optimizing students’ readiness and competence in delivering high-quality patient care. Future endeavors should focus on refining the 3D printing process, addressing challenges in automatization, and establishing a sustainable and accessible framework for widespread adoption in dental curricula. Further research shall quantify the impact of this approach on students’ performance in clinical treatment.
|
[
"Andrea Klink",
"Fabian Engelskirchen",
"Pablo Kaucher-Fernandez",
"Fabian Huettig",
"Ariadne Roehler"
] |
https://doi.org/10.3390/dj12070199
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999995 |
39056988_p0
|
39056988
|
sec[0]/p[0]
|
1. Introduction
| 3.972656 |
biomedical
|
Other
|
[
0.99267578125,
0.006389617919921875,
0.0009107589721679688
] |
[
0.047393798828125,
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] |
The maintenance of teeth within the oral cavity and their correct functioning are seen as critically important, and advanced dental procedures in the field of Endodontics fall within them . The great challenge of endodontic treatment is not to combat the bacteria present in the root canal, whether through mechanical removal—the use of endodontic files—or chemical removal—the use of irrigating substances . These micro-organisms are capable of inducing pulp inflammation, often leading to pulp death , and, sometimes even with antisepsis obtained through these techniques, the preparation is considered temporary and partial, and, because of this, the use of intracanal medications ends up being necessary .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056988_p1
|
39056988
|
sec[0]/p[1]
|
1. Introduction
| 3.755859 |
biomedical
|
Other
|
[
0.98974609375,
0.00885009765625,
0.0014820098876953125
] |
[
0.006927490234375,
0.9619140625,
0.0288543701171875,
0.0022716522216796875
] |
Intracanal medication is used in the tooth root canal between dental appointments. During that period, the medication continually releases active substances—which give the medication its antimicrobial potential, sealing ability, and biocompatibility . Several intracanal medications can be used, such as corticosteroids (Otosporin ® ), triple antibiotic paste (PTA), double antibiotic paste (PDA), 2% chlorhexidine (CXH), and calcium hydroxide [Ca(OH) 2 ] , with the treatment being the indicator of the best medication to be used, such as pulp revascularization therapy .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056988_p2
|
39056988
|
sec[0]/p[2]
|
1. Introduction
| 3.970703 |
biomedical
|
Other
|
[
0.9970703125,
0.0025997161865234375,
0.0004169940948486328
] |
[
0.2476806640625,
0.55908203125,
0.1890869140625,
0.004291534423828125
] |
Although they have several advantages, such as the antimicrobial and anti-inflammatory action mentioned above, some intracanal medications may negatively alter the tooth dentin re-resistance—a drawback for the endodontic/root canal therapy . Regenerative Endodontic Treatment, also known as Pulp Revascularization, is performed on permanent teeth diagnosed with pulp necrosis and incomplete rhizogenesis, as an alternative therapy to apexification . This treatment is a major challenge within Endodontics, since, when there is a necrotic process, the elimination of bacteria through filing is essential, but, in this case of an open apex, the use of files ends up further reducing the thickness of the walls, affectingexisting dentines. Therefore, the use of intracanal medications is the way to eliminate these micro-organisms .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056988_p3
|
39056988
|
sec[0]/p[3]
|
1. Introduction
| 3.90625 |
biomedical
|
Other
|
[
0.998046875,
0.0013322830200195312,
0.0003848075866699219
] |
[
0.1802978515625,
0.59912109375,
0.2178955078125,
0.0026836395263671875
] |
The objective of Pulp Revascularization is the creation of new pulp tissue from apical papilla stem cells (DPSCs) and other cells present in the peri-apical tissues induced by apical bleeding . Because of this objective, the intracanal medication used needs to be bio-compatible with the tissues and help induce the migration of DPSC into the root canal. Currently, the most used medications are calcium hydroxide, double-antibiotic, and trian-tibiotic paste .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056988_p4
|
39056988
|
sec[0]/p[4]
|
1. Introduction
| 4.066406 |
biomedical
|
Study
|
[
0.998046875,
0.0011758804321289062,
0.000629425048828125
] |
[
0.52099609375,
0.462646484375,
0.0150909423828125,
0.0014371871948242188
] |
Dentin microhardness is an important property for teeth undergoing revascularization therapy. Revascularization therapy is indicated for immature permanent teeth. Those teeth usually have thin root canal walls and an open apex before the therapy . Following the therapy protocol, a thicker intracanal structure is then expected —which should strengthen the tooth structure, allowing the tooth to remain in function . Although the formation of intracanal hard tissue may be favorable for tooth mechanical resistance, weak intracanal hard tissue could be formed—because of the reduced dentin microhardness after a period of contact with antibiotic medications. Ultimately, this weak formed structure would contribute to potential tooth fracture .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056988_p5
|
39056988
|
sec[0]/p[5]
|
1. Introduction
| 3.878906 |
biomedical
|
Review
|
[
0.9990234375,
0.0005030632019042969,
0.0005211830139160156
] |
[
0.308837890625,
0.00858306884765625,
0.68212890625,
0.0005946159362792969
] |
Scientific evidence shows that regenerative procedures are effective, with high percentages of success (78% to 100%) . However, despite the great success, some authors have stated that regenerative procedures might fail . The reasons for failure are root re-sorption, persistent infection, and tooth fracture. Tooth fracture is linked to a longer duration of intracanal medication, which may induce negative modifications in the tooth properties, such as changes in the mineral content ratio, increased permeability and solubility, and reduced microhardness of the root canal dentin .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056988_p6
|
39056988
|
sec[0]/p[6]
|
1. Introduction
| 3.636719 |
biomedical
|
Study
|
[
0.9990234375,
0.00014960765838623047,
0.0006165504455566406
] |
[
0.9951171875,
0.0015411376953125,
0.003078460693359375,
0.00010102987289428711
] |
Studies found a significant reduction in microhardness of root dentin treated with antibiotic pastes when compared to untreated root dentin . However, some studies did not use the values of calcium-hydroxide-treated dentin as a comparison to antibiotic-treated dentin , and it is accepted that calcium hydroxide is also capable of reducing dentin microhardness . This point is a gap within the literature, justifying, therefore, the present study.
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056988_p7
|
39056988
|
sec[0]/p[7]
|
1. Introduction
| 4.101563 |
biomedical
|
Study
|
[
0.99853515625,
0.0010137557983398438,
0.00023615360260009766
] |
[
0.9990234375,
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0.00040340423583984375,
0.0001232624053955078
] |
Considering the importance of having detailed knowledge about the potential negative effects that antibiotic pastes might cause on the root dentin during regenerative procedures, the purpose of this study was to investigate dentin microhardness in three different locations distancing from the canal lumen after 20 days of treatment with a tri-antibiotic paste (TAP) (ciprofloxacin, metronidazole, and minocycline), and with a double-antibiotic paste (DAP) (ciprofloxacin and metronidazole), with calcium hydroxide-treated dentin as comparison. The expectation was that antibiotic pastes would reduce the dentin microhardness to a lesser extent than calcium hydroxide. The null hypothesis was that there would be no difference in dentin microhardness treated with TAP, DAP, or calcium hydroxide paste [Ca(OH) 2 ].
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999999 |
39056988_p8
|
39056988
|
sec[1]/sec[0]/p[0]
|
2.1. Study Design and Ethics
| 3.914063 |
biomedical
|
Study
|
[
0.9990234375,
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] |
[
0.99755859375,
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0.0001583099365234375
] |
This is an in vitro experiment that used human teeth to measure dentin microhard-ness depending on which intracanal medication was used: (1) tri-antibiotic paste com-posed of ciprofloxacin, metronidazole, and minocycline (TAP); (2) double-antibiotic paste composed of ciprofloxacin and metronidazole (DAP); and (3) calcium hydroxide paste, (Ul-tracalTM XS, Ultradent, South Jordan, UT, USA) [Ca(OH) 2 ]. The project protocol was approved by the Ethics Committee Board where the experiment was conducted .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056988_p9
|
39056988
|
sec[1]/sec[1]/p[0]
|
2.2. Sample Size Calculation and Teeth Collection
| 3.998047 |
biomedical
|
Study
|
[
0.9990234375,
0.0005869865417480469,
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] |
[
0.99755859375,
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] |
Sample size calculation was performed to compare the means of microhardness (KHN) between groups. The following parameters were adopted: confidence level of 95%, power of 80%, standard deviation of 5, and a minimum difference to be detected between the groups of 5 points in the mean microhardness. The n obtained was 16 samples/specimens per group. As each tooth would originate 4 specimens after sectioning (more information is shown below in Section 2.3 ), there was a need for 48 teeth. The sample size calculation and the methodology followed a previous study .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999999 |
39056988_p10
|
39056988
|
sec[1]/sec[1]/p[1]
|
2.2. Sample Size Calculation and Teeth Collection
| 4.035156 |
biomedical
|
Study
|
[
0.99560546875,
0.00414276123046875,
0.00037026405334472656
] |
[
0.9970703125,
0.0020656585693359375,
0.00026154518127441406,
0.0003631114959716797
] |
With forty-eight unidentifiable and untraceable human mandibular premolars, the extracted teeth were all caries-free. All the teeth were extracted for orthodontic, periodontal, or other dental treatment reasons. Organic material was removed from the root surface with curettes. Teeth were stored in 0.1% thymol at 4 °C and used within 6 months after extraction. Radiographs and visual assessments under magnification were used for teeth selection. Teeth were included if they had a single canal, completed closed apex, and no signs of calcification, internal resorption, or previous endodontic treatment. We exclude the teeth that had large cavities, fracture roots, and extensive restorations.
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056988_p11
|
39056988
|
sec[1]/sec[2]/p[0]
|
2.3. Specimen Preparation (Root Slice Fabrication and Treatment with Medication Pastes)
| 4.011719 |
biomedical
|
Study
|
[
0.9736328125,
0.025482177734375,
0.0006971359252929688
] |
[
0.68701171875,
0.300537109375,
0.002742767333984375,
0.0097808837890625
] |
Teeth were decoronated at the cementoenamel junction using a cutting machine . Working length for each root was measured by inserting a size #10 K-file (Maillefer, Dentsply Industria e Comercio Ltda, Petropolis, RJ, Brazil) into the root canal until the tip of the file was visualized in the apical foramen. The file was then pulled back 1 mm—under a stereoscopic magnifying glass of 25× (Baush, Lomb, Rochester, NY, USA).
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056988_p12
|
39056988
|
sec[1]/sec[2]/p[1]
|
2.3. Specimen Preparation (Root Slice Fabrication and Treatment with Medication Pastes)
| 4.007813 |
biomedical
|
Study
|
[
0.966796875,
0.03228759765625,
0.0007042884826660156
] |
[
0.5947265625,
0.385009765625,
0.0031948089599609375,
0.017120361328125
] |
Root canals were negotiated with a size #10 K-file, and then cleaned and shaped with a single reciprocating nickel–titanium instrument (Reciproc R50—VDW, München, Germany), an instrument that has a taper of 0.06, under irrigation with 10 mL of 1% sodium hypochlorite at pH 11. EDTA was not used. The Reciproc R40 file was used in X-Smart Plus (Dentsply, Maillefer, Switzerland) programmed in Reciproc All mode. During instrumentation, the root canals were irrigated with 2 mL 1% NaOCl (Fórmula e Ação, São Paulo, SP, Brazil) and, finally, rinsed with sterile saline to remove dentin debris.
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056988_p13
|
39056988
|
sec[1]/sec[2]/p[2]
|
2.3. Specimen Preparation (Root Slice Fabrication and Treatment with Medication Pastes)
| 4.085938 |
biomedical
|
Study
|
[
0.99755859375,
0.0020656585693359375,
0.0003101825714111328
] |
[
0.99755859375,
0.0018167495727539062,
0.00023508071899414062,
0.0001990795135498047
] |
Four root specimens/slices (2 mm thickness) were obtained from the middle third of each root using the cutting machine. The specimens were embedded in PVC tubes with acrylic resin (TDV, Pomerode, SC, Brazil) with one of the dentin surfaces (and canal space) facing up, and free of resin. The dentin surfaces were sanded with 400#, 600#, and 1200# grids of sandpaper, and then polished with felt cloths soaked in paste diamond (Diamond, FGM, Joinville, SC, Brazil) at low-speed rotation . After cleaning the specimens in an ultrasonic vat under distilled water for 3 min and drying them with paper towel, specimens were divided at random in 3 groups (n = 16) according to the intracanal medication to be used.
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056988_p14
|
39056988
|
sec[1]/sec[2]/p[3]
|
2.3. Specimen Preparation (Root Slice Fabrication and Treatment with Medication Pastes)
| 4.074219 |
biomedical
|
Study
|
[
0.9990234375,
0.0006437301635742188,
0.0002601146697998047
] |
[
0.9951171875,
0.00437164306640625,
0.0004105567932128906,
0.00017118453979492188
] |
The antibiotic pastes were fabricated by grounding one tablet of each antibiotic (500 mg) to obtain a mixture 1:1:1 (TAP) or 1:1 (DAP) by weight, measured in a precision scale . The pastes were then produced by mixing the powder with saline solution. The following powder/liquid ratios were used: (1) TAP = 3:1, and (2) DAP = 2.5:1. Antibiotic pastes were applied over the dentin samples and into individual containers using a metallic spatula. UltracalTM XS (Ultradent, Itaici—Indaiatuba, São Paulo, Brazil) is a premixed Ca(OH) 2 paste for direct application, and it was applied over the samples and into the containers using 29 ga NaviTip tips with single sideport (Indaiatuba, SP, Brazil).
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056988_p15
|
39056988
|
sec[1]/sec[2]/p[4]
|
2.3. Specimen Preparation (Root Slice Fabrication and Treatment with Medication Pastes)
| 3.943359 |
biomedical
|
Study
|
[
0.99755859375,
0.0020999908447265625,
0.00031685829162597656
] |
[
0.98828125,
0.0107269287109375,
0.00038909912109375,
0.0003635883331298828
] |
The specimens (root discs) were placed in Petri dishes, and then assigned randomly to the three treatment groups. The medicaments were placed in the Petri dishes, and the discs were completely covered with the mixture. The Petri dishes were covered with stretch film and remained in an incubator at 37 °C and 100% humidity (distilled water) for 20 days. After treatment, specimens were cleaned in ultrasonic vat for 3 min and dried.
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056988_p16
|
39056988
|
sec[1]/sec[3]/p[0]
|
2.4. Microhardness Test (Before and After Treatment with Medications)
| 4.152344 |
biomedical
|
Study
|
[
0.99951171875,
0.00033974647521972656,
0.00030517578125
] |
[
0.9990234375,
0.00027298927307128906,
0.0004448890686035156,
0.00006103515625
] |
Dentin microhardness were acquired at Day-0 (baseline/before medication treatment) and after 20 days immersed in the medication (Day-20). Microhardness was measured with a Knoop indenter at 40× magnification A pyramid-shaped diamond indenter was used to analyze them with a load of 10 g for 15 s. The mean length of the two diagonals in each indentation was used to calculate the Knoop microhardness value [KHN]. The Knoop method is often used when lighter loads are needed (as in our study), where very small loads are recommended to be able to note changes in human dentin microhardness—and the shape of the probe is suitable for samples needing indentations close together or on the edge. Because of the large difference between the long and short Knoop diagonals, the Knoop indenter is often better suited for determining variations of hardness over very small distances compared to the Vickers indenter. It can also offer higher levels of precision than the Vickers method, due to the fact that the longitudinal diagonal of the indenter is higher .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056988_p17
|
39056988
|
sec[1]/sec[3]/p[1]
|
2.4. Microhardness Test (Before and After Treatment with Medications)
| 4.125 |
biomedical
|
Study
|
[
0.99951171875,
0.00039505958557128906,
0.0003249645233154297
] |
[
0.99951171875,
0.00028514862060546875,
0.00018739700317382812,
0.00006151199340820312
] |
Twelve indentations were performed for each specimen: 3 indentations in the upper region (at 25 µm, 50 µm, and 100 µm from the root canal lumen), 3 indentations in the lower region (at 25 µm, 50 µm, and 100 µm), 3 indentations in the right region (at 25 µm, 50 µm, and 100 µm) and 3 indentations in the left region (at 25 µm, 50 µm, and 100 µm). Each disc received a series of three indentations at points around the pulp space 1 mm from the canal wall. The representative microhardness value for each distance in the specimen was obtained by averaging the result of the 4 indentations (upper, lower, left, and right) performed in the distance . All tests carried out were guided by the ASTM E384-22 standard .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056988_p18
|
39056988
|
sec[1]/sec[4]/p[0]
|
2.5. Data Analysis
| 4.011719 |
biomedical
|
Study
|
[
0.99951171875,
0.00033855438232421875,
0.00026726722717285156
] |
[
0.9990234375,
0.00041484832763671875,
0.00028228759765625,
0.00006324052810668945
] |
Day-0 and Day-20 dentin microhardness values (KHN) were compared intra-group using Wilcoxon’s test. Dentin microhardness for independent groups [TAP, DAP, and Ca(OH) 2 ] in each distance from the canal lumen (25 µm, 50 µm, and 100 µm) were compared using Mann–Whitney’s and Kruskal–Wallis’ tests. Analyses were performed using the Statistical Package for Social Sciences (SPSS for Windows, version 21.0, SPSS Inc. Chicago, IL, USA), at α = 5%.
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999999 |
39056988_p19
|
39056988
|
sec[2]/p[0]
|
3. Results
| 4.027344 |
biomedical
|
Study
|
[
0.99853515625,
0.0008897781372070312,
0.0003948211669921875
] |
[
0.99951171875,
0.00038552284240722656,
0.0001932382583618164,
0.00007700920104980469
] |
There was no statistical difference for the baseline (Day-0) microhardness considering the specimens allocated for the three groups ( p > 0.05), demonstrating the effectiveness of the random allocation. There was no statistical difference for the baseline microhardness considering the distance from the canal lumen (25 µm, 50 µm, and 100 µm) ( p > 0.05) .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056988_p20
|
39056988
|
sec[2]/p[1]
|
3. Results
| 4.078125 |
biomedical
|
Study
|
[
0.9990234375,
0.00044226646423339844,
0.0005545616149902344
] |
[
0.99951171875,
0.00018584728240966797,
0.00018990039825439453,
0.000048100948333740234
] |
In the intra-group comparison (same distances), the microhardness values (KHN) in all the tested groups [TAP, DAP, and Ca(OH) 2 ] were significantly reduced on Day-20 of the experimental time in comparison with Day-0 ( p < 0.001 for the three medications). Individual results for each experimental time are shown in Table 1 and Table 2 ).
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056988_p21
|
39056988
|
sec[2]/p[2]
|
3. Results
| 4.0625 |
biomedical
|
Study
|
[
0.99853515625,
0.0005936622619628906,
0.0007596015930175781
] |
[
0.99951171875,
0.0002510547637939453,
0.00019407272338867188,
0.00004869699478149414
] |
In the comparison between groups (same distances), the Day-0 measurements, regardless of the measured distance, were similar to each other ( p > 0.05). For the Day-20 measurements, the Ca(OH) 2 group had higher microhardness values than TAP and DAP, regardless of the measured distance ( p < 0.05). The TAP and DAP groups had similar values, regardless of the measured distance ( p > 0.05).
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056988_p22
|
39056988
|
sec[3]/p[0]
|
4. Discussion
| 3.800781 |
biomedical
|
Other
|
[
0.994140625,
0.005481719970703125,
0.00052642822265625
] |
[
0.03680419921875,
0.9228515625,
0.037109375,
0.0030670166015625
] |
Root-canal-treated teeth need to remain micro-organism-free, as an infection or reinfection would end up hindering the progress of the treatment. Inter-appointment intracanal medication prevents recontamination and counteracts the effects of micro-organisms that have resisted the cleaning and shaping procedures . Among them, a combination of antibiotics is the most used for regenerative endodontic therapy .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056988_p23
|
39056988
|
sec[3]/p[1]
|
4. Discussion
| 2.722656 |
biomedical
|
Other
|
[
0.99755859375,
0.0010738372802734375,
0.0015325546264648438
] |
[
0.1400146484375,
0.8525390625,
0.005889892578125,
0.0018033981323242188
] |
The literature has shown that antibiotic pastes may reduce human dentin microhardness in vitro. In a clinical situation, this would be disadvantageous for immature teeth, because it could weaken the tooth, leading to fracture.
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056988_p24
|
39056988
|
sec[3]/p[2]
|
4. Discussion
| 4.078125 |
biomedical
|
Study
|
[
0.99951171875,
0.00042700767517089844,
0.00023674964904785156
] |
[
0.99951171875,
0.00020492076873779297,
0.0003161430358886719,
0.00006890296936035156
] |
This study showed that, as expected, dentin microhardness decreased after having remained 20 days in contact with antibiotic medications pastes (TAP and DAP), as well as when in contact with Ca(OH) 2 . Contrary to our assumption, Ca(OH) 2 affected dentin microhardness to a lesser extent in comparison with antibiotic pastes (with or without minocycline), regardless of the dentin location (closer or further from the canal lumen).
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39056988_p25
|
39056988
|
sec[3]/p[3]
|
4. Discussion
| 2.667969 |
biomedical
|
Other
|
[
0.9951171875,
0.00347900390625,
0.0014333724975585938
] |
[
0.006710052490234375,
0.98779296875,
0.00406646728515625,
0.0015439987182617188
] |
The most used intracanal medication in regenerative procedures is TAP , but DAP has also been used to avoid the tooth discoloration effect of minocycline . Calcium hydroxide is an alternative used to disinfect the canal during endodontic regeneration .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056988_p26
|
39056988
|
sec[3]/p[4]
|
4. Discussion
| 4.011719 |
biomedical
|
Other
|
[
0.98828125,
0.01068878173828125,
0.001186370849609375
] |
[
0.043914794921875,
0.88134765625,
0.07049560546875,
0.004146575927734375
] |
Regenerative procedures are indicated to treat immature teeth with infected necrotic pulps, and the technique yields no or minimal mechanical shaping in the canal walls. This aims to prevent the removal of the dentinal structure because the tooth is already fragile . To obtain the appropriate disinfection without shaping the canal walls, it is recommended that the intracanal medication with antibiotic pastes remain for approximately 21 days . The medication concomitantly disinfects the environment and induces dentin apposition and root development . The apposition of dentin and mineralized tissues would ultimately reduce the risk of fracture associated with traditional treatments, such as the apexification with Ca(OH) 2 or the MTA-apical plug technique .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056988_p27
|
39056988
|
sec[3]/p[5]
|
4. Discussion
| 4.101563 |
biomedical
|
Study
|
[
0.99951171875,
0.00041961669921875,
0.00023126602172851562
] |
[
0.99951171875,
0.00023543834686279297,
0.0003046989440917969,
0.000072479248046875
] |
Extrapolating the results obtained in this current study, the clinical use of antibiotic intracanal medication for 20 days would reduce dentin microhardness, which could in-duce the formation of a weakened intracanal structure. The dentin samples treated with TAP had an average reduction of approximately 24 KHN in relation to the baseline (dentin before treatment) (see Table 1 ). Similarly, DAP had an average reduction of 20 KHN. These values may not be clinically relevant; however, what we know for sure is that anti-biotic pastes reduced dentin microhardness more than Ca(OH) 2 —a material that has well-known negative effects on dentin . This study showed that 20 days of medication with Ca(OH) 2 promoted a reduction in dentin microhardness of only 10 KHN (on average).
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056988_p28
|
39056988
|
sec[3]/p[6]
|
4. Discussion
| 4.042969 |
biomedical
|
Study
|
[
0.99951171875,
0.00023686885833740234,
0.0002925395965576172
] |
[
0.99951171875,
0.00027632713317871094,
0.00020420551300048828,
0.000049948692321777344
] |
The reduction in microhardness may have originated from the demineralizing effects of these acidic antibiotic mixtures when used at higher concentrations (as with the ones used in this current study). The minocycline, present in TAP, is considered to be responsible for causing dentinal demineralization . However, this current study did not find differences in microhardness reduction after treating dentin samples with an antibiotic paste with minocycline (TAP) or without minocycline (DAP).
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056988_p29
|
39056988
|
sec[3]/p[7]
|
4. Discussion
| 4.207031 |
biomedical
|
Study
|
[
0.99951171875,
0.00016760826110839844,
0.000164031982421875
] |
[
0.9892578125,
0.0023021697998046875,
0.0083160400390625,
0.00015676021575927734
] |
The acidic characteristic of ciprofloxacin, metronidazole, and minocycline has the potential to demineralize the inorganic component of dentin. The monoclinic compound present in the crystal phase of pastes becomes attached to the calcium ions by chelation, inducing, therefore, a decrease in the hydroxyapatite of dentin . A similar chelation process was demonstrated when root repair materials were exposed to acidic environments . Chelating agents are substances that remove calcium ions from dentin, causing a decrease in microhardness and increasing dentin permeability . Dentin erosion (the loss of calcium and phosphorous) is also reported upon the use of chelating substances, such as EDTA and TAP .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056988_p30
|
39056988
|
sec[3]/p[8]
|
4. Discussion
| 4.117188 |
biomedical
|
Study
|
[
0.99951171875,
0.00027251243591308594,
0.0002796649932861328
] |
[
0.99951171875,
0.00017464160919189453,
0.0004208087921142578,
0.000050127506256103516
] |
Dentin microhardness might vary depending on the proximity with the canal lumen . When the medication is inserted into the root canal , a higher variation in microhardness may occur in the pre-dentin layer, i.e., closer to the canal lumen . On the other hand, in experiments in which dentin samples are covered or immersed in the medication (as in this study), the same effect would occur regardless of the proximity to the canal lumen. This current study was accurate in showing the same reduction in dentin microhardness in different locations at the dentin wall (25 µm, 50 µm, or 100 µm). It is possible to understand that there was no variation depending on the proximity of the canal lumen; that is, regardless of the depth of penetration of the intracanal medication, the entire dentin wall will undergo changes in its microhardness, being susceptible to fracture, and these results differ from the results that were found by Haapasalo et al. and Wang et. al. .
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999999 |
39056988_p31
|
39056988
|
sec[3]/p[9]
|
4. Discussion
| 4.117188 |
biomedical
|
Study
|
[
0.99951171875,
0.0004944801330566406,
0.00023543834686279297
] |
[
0.99951171875,
0.00021016597747802734,
0.00038695335388183594,
0.0000768899917602539
] |
This study had strengths and weaknesses. It was valuable to show the amount of microhardness reduction in dentin samples treated with antibiotic pastes in comparison to the dentin treated with Ca(OH) 2 , which is a medication well-discussed in the literature. Also, this experiment did not use EDTA to wash the dentin samples before the immersion in the medications. It is known that EDTA irrigation (before or after the insertion of antibiotic pastes into the root canal) might result in a significant reduction in root dentin hardness ranging from 58% to 70% . We had operators experienced and trained with the equipment and the methodology, which ensured the optimal standardization of the study protocol. A negative point of this study is the impossibility to say that the same results would occur in clinical practice (and the challenges of a clinical study in testing identical outcomes). Another limiting factor is the difficulty (or even the impossibility) to obtain and standardize immature teeth. Furthermore, we (dentists) cannot control or predict the characteristics/mechanical properties (such as dentin composition, the arrangement of hydroxyapatite crystals, etc.) of a non-vital tooth in a clinical situation because they vary from patient to patient. These characteristics/mechanical properties are also altered and more unpredictable in non-vital teeth compared to vital teeth . This ends up being a limitation of this study, since controlling these characteristics is a challenge for in vitro studies. Another possible limitation of the present study was the microhardness readings in different thirds of the dentin. The differences between the thirds of the root dentin were diluted in the same average per tooth. However, the study used 16 teeth per group, a highly robust number to bring reliability to the result. This high number of teeth per group enhanced the statistical analysis and diluted the variability in dentin morphology.
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39056988_p32
|
39056988
|
sec[4]/p[0]
|
5. Conclusions
| 4.050781 |
biomedical
|
Study
|
[
0.9990234375,
0.0006012916564941406,
0.0001665353775024414
] |
[
0.99853515625,
0.0008091926574707031,
0.0005993843078613281,
0.00012683868408203125
] |
Based on the results of this in vitro study, the following conclusions were drawn: - Ca (OH) 2 is more appropriate to be used as intracanal medication for 20 days than antibiotic pastes (TAP or DAP) during regenerative procedures. - Ca (OH) 2 reduced dentin microhardness significantly less compared to the reduction caused by the antibiotic pastes (TAP or DAP), which have chelating properties.
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39056988_p33
|
39056988
|
sec[4]/p[1]
|
5. Conclusions
| 2.787109 |
biomedical
|
Other
|
[
0.99072265625,
0.0005698204040527344,
0.00864410400390625
] |
[
0.123046875,
0.8720703125,
0.004558563232421875,
0.0005283355712890625
] |
Although microhardness has been used as an indicator of the overall resistance of dentin, it is important to highlight that the quality of dentin also depends on other properties, such as tensile strength, modulus of elasticity, etc.
|
[
"Amanda Palmeira Arruda Nogueira",
"Renata Grazziotin-Soares",
"Adriana Marques Mesquita Leal",
"Sérgio Alves Guida Freitas Júnior",
"Bruna Laís Lins Gonçalves",
"José Bauer",
"Meire Coelho Ferreira",
"Ceci Nunes Carvalho"
] |
https://doi.org/10.3390/dj12070201
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39057497_p0
|
39057497
|
sec[0]/p[0]
|
1. Introduction
| 4.296875 |
biomedical
|
Review
|
[
0.98486328125,
0.0013275146484375,
0.01369476318359375
] |
[
0.0743408203125,
0.003345489501953125,
0.921875,
0.0002951622009277344
] |
In recent years, there has been a growing emphasis on the development of bio-based composites. Many studies have thoroughly explored different categories of bio-based materials, including cellulose and its derivatives, chitin-chitosan, polylactic acid, and polybutylene succinate. These materials are recognized for their potential environmental safety and non-toxicity, even when they reach the end-of-use stage . Consequently, bio-based materials have seen widespread development, spanning from academic research to industrial adoption across various applications. These applications include infrastructure and building materials, automotive components, food packaging, as well as medical and pharmaceutical technologies. Moreover, the exploration of bio-based materials has centered on the concept of the bio-economy, which entails leveraging biotechnology-driven economic activities to establish industrial processes . Cellulose is a widely available, eco-friendly material known for its mechanical strength, biocompatibility, hydrophilicity, and thermostability . Traditionally used in energy, construction, fabrics, and paper production, technological advancements have expanded its applications to chemical-based materials. Research has investigated its use in pharmaceuticals, membranes and filtration, drug delivery, and as a stabilizer and emulsifier . Additionally, cellulose has been advanced for paper-based technologies, such as bioactive paper for clinical diagnosis, environmental monitoring, food quality control, and biosensors. Innovations include gamma-irradiated paper and biohybrid cellulose paper with wet strength properties. However, producing high-purity cellulose requires removing lignin, hemicellulose, and pectin, a process that is pollution-prone and energy-intensive with costly waste treatment . Consequently, developing highly pure and environmentally friendly cellulose remains a key focus .
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39057497_p1
|
39057497
|
sec[0]/p[1]
|
1. Introduction
| 4.324219 |
biomedical
|
Review
|
[
0.9462890625,
0.00104522705078125,
0.052825927734375
] |
[
0.362060546875,
0.0163421630859375,
0.62109375,
0.0005216598510742188
] |
Aerogels are extremely porous open-cell solids with roughly 90% porosity produced by a supercritical drying method. Their relatively low thermal conductivity (from 0.013 W/m K) results in them being ideal thermal super-insulators. The low density (80–200 kg/m 3 ) and complicated solid nanostructure, with mesopore widths ranging from 4 to 20 nm, reduce heat conduction and contribute to their high efficiency . Aerogels can be made from a variety of resources, including inorganic compounds, synthetic polymers, and natural polymers , such as cellulose . The initial component defines the particular kind of aerogel formed . Cellulose aerogels are notable for their renewability, biocompatibility, and biodegradability, along with low density (0.5–350 kg/m 3 ), high porosity (84.0–99.9%), and a large specific surface area. These characteristics make them highly promising materials for the 21st century. They also offer superior compressive strength and excellent biodegradability. Eco-friendly and versatile, cellulose aerogels are ideal for applications in adsorption and oil/water separation, heat separation, biomedical materials, and metal nanoparticle/metal oxide carriers and as precursors for carbon aerogels. Their high reusability reduces economic losses, and their natural decomposition prevents additional environmental harm .
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39057497_p2
|
39057497
|
sec[0]/p[2]
|
1. Introduction
| 4.558594 |
biomedical
|
Study
|
[
0.9970703125,
0.0005536079406738281,
0.0025348663330078125
] |
[
0.63623046875,
0.00392913818359375,
0.359130859375,
0.0004820823669433594
] |
Bacterial cellulose represents an alternative source of cellulose distinct from plant-derived cellulose. It is synthesized by various genera of bacteria, including Acetobacter , Achromobacter , Agrobacterium , and Sarcina . It serves as a hydrogel due to its inherent purity and remarkable hydrophilicity, necessitating no additional treatment and preserving its original properties. These distinctive attributes of bacterial cellulose pave the way for numerous novel applications, as its properties can be tailored by adjusting the fermentation process. In comparison to plant cellulose, bacterial cellulose offers several advantages. Foremost among these is its exceptional purity, as it lacks the hemicelluloses and lignin found in plant cellulose, thereby reducing the need for extensive processing steps. Additionally, the structure of bacterial cellulose is superior, characterized by longer and finer fiber lengths that are approximately a hundred times smaller in proportion, contributing to its enhanced strength and fineness compared to plant cellulose . The cellulose chains are bound together by both intra- and intermolecular hydrogen bonds, which gives BC its specific properties like exceptional purity, strong water retention, poor solubility, mechanical resilience, plasticity, biodegradability, biocompatibility, non-toxicity, and non-allergenicity . Furthermore, its physiochemical qualities make it desirable for usage in both the textile and paper industries along with the other applications because of its multifunctionality. Its Young’s modulus is 20,000 mPa for sheets and 130,000 mPa for single fibers compared to plant cellulose, which is 25–200 mPa .
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39057497_p3
|
39057497
|
sec[0]/p[3]
|
1. Introduction
| 4.1875 |
biomedical
|
Review
|
[
0.98779296875,
0.005191802978515625,
0.007167816162109375
] |
[
0.0098114013671875,
0.0010395050048828125,
0.98876953125,
0.000476837158203125
] |
The properties of BC, such as degree of polymerization, crystallinity, and moisture absorption, can undergo alterations depending on various factors, including culturing conditions, the type of microorganism, and nutrients present in the growth medium. Several studies have highlighted specific effects, such as the impact of dehydration/rehydration on BC tensile strength ; the influence of polymer treatment methods on mechanical properties ; the correlation between microorganism type, drying method, and Young’s modulus value ; and the relationship between culture medium composition, pH, and crystallinity . Furthermore, incorporating collagen between bacterial cellulose fibers has been shown to improve thermal stability and cytocompatibility through collagen fibrillogenesis, contributing to enhanced properties of BC-based materials . Drying methods are crucial to the structure, performance, and application of BC films . Research findings indicate that the method used for drying can influence the mechanical properties of bacterial cellulose (BC) films, including parameters such as tensile strength, Young’s modulus, and water absorption capacity, as well as the micromorphology, crystallinity, and thermal characteristics of the material . This review examines the effects of various drying techniques on the thermal and mechanical properties of bacterial cellulose aerogels and their composites, highlighting their multifunctional applications and future potential. The review mostly encompasses studies from 2014 to 2024, focusing on different bacterial cellulose aerogels and comparing the impacts of various drying methods on their properties. Non-peer-reviewed articles were excluded from the analysis.
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39057497_p4
|
39057497
|
sec[1]/p[0]
|
2. Production of Bacterial Cellulose Aerogel
| 4.71875 |
biomedical
|
Study
|
[
0.99853515625,
0.0005993843078613281,
0.0009937286376953125
] |
[
0.96728515625,
0.0007266998291015625,
0.03179931640625,
0.0002808570861816406
] |
The cellulose produced by bacteria (BC) stands out from other cellulose sources for environmentally friendly applications. BC, unlike plant cellulose, is an extracellular polymer, which allows for high-purity extraction devoid of lignin and hemicellulose . It has a high degree of polymerization and crystallinity, as well as a unique micro- or nano-sized fiber network, which increases its surface-to-volume ratio . Bacterial cellulose (BC) production is mostly dependent on the nutritional makeup of the production medium, particularly carbon sources. Although many carbon sources and culture mediums have been investigated, the Hestrin–Schramm (HS) medium is the most often utilized . However, its high cost, which accounts for 30% of overall production expenses, presents a significant barrier to commercial-scale fabrication . Using agro-industrial waste for sustainable BC production is a desirable and cost-effective option . Additionally, the selection of a BC-producing bacterium is critical , and cellulose production by bacteria has been observed across various species. Among the bacterial strains identified, the majority belong to Gram-negative species such as Acetobacter , Azotobacter , Rhizobium , Pseudomonas , Salmonella , Agrobacterium , Aerobacter , Achromobacter , and Alcaligenes . Additionally, Gram-positive species like Sarcina ventriculi , Salmonella , and Escherichia also demonstrate the capability to produce cellulose. Among the various bacterial strains identified, A. xylinum is recognized as one of the most promising strains for cellulose production due to its large production capacity, made possible by many copies of BC synthesis genes in its genome . It has been documented that under optimal conditions, bacteria can convert nearly 50% of the carbon source provided in the medium into cellulose, forming a pellicle. Specifically, A. xylinum is a Gram-negative aerobic strain characterized by its rod-shaped morphology. This bacterium produces cellulose through its primary metabolic activity, forming interwoven ribbons. A notable advantage of A. xylinum is its ability to produce cellulose from various carbon sources. BC finds application in diverse fields, necessitating the optimization of its production for economic viability. Substantial research has explored optimal growth conditions to achieve high BC yields across different media, cultivation techniques, and environmental factors, including agitation levels, carbon and nitrogen sources, incubation duration, and medium volume . Additional factors such as microorganism type, pH levels, and oxygen supply have been thoroughly investigated as they directly influence the characteristics of BC. Such studies are essential for comprehending how growth conditions affect the morphology and properties of BC . As the cellulose structure and its physical and mechanical characteristics are purely affected by the cultivation process of bacterial cellulose, the methods for producing bacterial cellulose are critical parameters. Generally, cellulose production by bacteria occurs under two distinct conditions: (i) static conditions and (ii) agitated conditions . Under static conditions, the bacterial culture and medium are left undisturbed in an aerated dark environment until fermentation is complete. In the agitated culture method, continuous stirring is maintained throughout the fermentation period. In the former case, cellulose pellicle forms as a continuous mat-like structure, while in the latter case, although cellulose growth is faster, there occurs the formation of round cellulose balls .
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999994 |
39057497_p5
|
39057497
|
sec[1]/sec[0]/p[0]
|
2.1. Static Culture
| 4.179688 |
biomedical
|
Study
|
[
0.99951171875,
0.0002536773681640625,
0.00034999847412109375
] |
[
0.99658203125,
0.000247955322265625,
0.002956390380859375,
0.00006455183029174805
] |
In this approach, the nutrient medium is tailored to meet the specific requirements of the bacterial strain. Following inoculation, the medium remains undisturbed. In cellulose production, during static conditions, aerating the medium in a well-ventilated area enhances production by ensuring adequate oxygen supply. Additionally, some researchers have noted that cellulose production from Acetobacter xylinum species may be increased by excluding light. Although the static culture method is widely used, its primary drawback is the extended fermentation period. Moreover, inadequate nutrient and oxygen distribution during fermentation can lead to uneven cellulose production, resulting in variations in thickness across the cellulose mat . Hsieh and colleagues introduced a modified approach within the static culture method itself, involving intermittent feeding of the nutrient medium during cultivation. In this method, after a certain number of days of fermentation, a fresh batch of nutrient medium is introduced into the existing static culture medium. This new medium is poured directly onto the newly formed pellicle from the previous fermentation cycle. This process can be repeated multiple times until several layers of pellicles are formed. The researchers observed that this method enables continuous cellulose production, with an average of 0.02 g/day even after 30 days of cultivation, in contrast to the previous cultivation method where production ceases entirely . Figure 2 depicts the BC production in static and agitated/shaking environments as each method offers distinct benefits.
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999999 |
39057497_p6
|
39057497
|
sec[1]/sec[0]/sec[0]/p[0]
|
Fed-Batch
| 3.613281 |
biomedical
|
Other
|
[
0.994140625,
0.001071929931640625,
0.0050201416015625
] |
[
0.07098388671875,
0.92529296875,
0.0033054351806640625,
0.00038933753967285156
] |
In a fed-batch process, the operation begins as a batch process, but nutrients are later added either continuously or intermittently for a set duration without removing any culture fluid. This method keeps the substrate concentration at optimal levels for microorganism performance .
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39057497_p7
|
39057497
|
sec[1]/sec[1]/p[0]
|
2.2. Agitated/Shaking Culture
| 4.03125 |
biomedical
|
Study
|
[
0.99951171875,
0.00014841556549072266,
0.0004944801330566406
] |
[
0.98779296875,
0.0027313232421875,
0.00943756103515625,
0.00009238719940185547
] |
Unlike the static method, in the dynamic method, the inoculated culture medium is placed in a rotary shaker throughout the fermentation or incubation period. The constant agitation of the culture enhances oxygen supply in the liquid medium containing the A. xylinum bacterial strain. However, this method results in cellulose formation in the shape of spheres, or it can be manufactured in other diverse shapes including fibrous suspensions, pellets, and irregular masses . Therefore, this approach is more conducive to achieving higher cellulose production within a shorter timeframe compared to the static medium . Table 1 simply shows the generic comparison of the static and agitated culture of bacterial cellulose production methods with their properties, nutrition type, production yield, etc.
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39057497_p8
|
39057497
|
sec[1]/sec[1]/sec[0]/p[0]
|
Bioreactor Culture
| 3.878906 |
biomedical
|
Study
|
[
0.99853515625,
0.00010097026824951172,
0.0012302398681640625
] |
[
0.99267578125,
0.0032024383544921875,
0.004108428955078125,
0.00006657838821411133
] |
To address the emergence of non-cellulose mutants in agitated culture and enhance the efficiency of BC production, various types of bioreactors have been utilized. These bioreactors have been found to yield significant amounts of BC. Different bioreactor configurations for BC cultures are distinguished by their operational methods, such as BC production under oxygen-enriched air, the utilization of rotating discs, or reliance on biofilm support .
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39057497_p9
|
39057497
|
sec[2]/p[0]
|
3. Effect of Drying Characteristics of Bacterial Cellulose Aerogels on Their Thermal and Mechanical Behavior
| 3.849609 |
biomedical
|
Study
|
[
0.9970703125,
0.00017833709716796875,
0.002948760986328125
] |
[
0.931640625,
0.003932952880859375,
0.06402587890625,
0.00014507770538330078
] |
Bacterial cellulose and its composites can undergo various characterization methods, with the significance of these properties differing depending on the application. The rapid advancements in hydrogel research have placed hydrogels in scenarios that test their thermal and mechanical limits . On that point, the drying methods of the BC aerogels are also important as well as its growing methods because drying can dramatically affect its characteristics, such as pores, specific surface area, morphology, crystallinity, absorbability, and, additionally, thermal and mechanical properties. In this section, the thermal and mechanical behavior of BC aerogels is discussed in detail. Figure 3 depicts the most used drying methods for bacterial cellulose aerogels.
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39057497_p10
|
39057497
|
sec[2]/sec[0]/sec[0]/p[0]
|
3.1.1. Hot Air Drying
| 2.613281 |
biomedical
|
Other
|
[
0.822265625,
0.0017528533935546875,
0.1761474609375
] |
[
0.1883544921875,
0.80712890625,
0.004047393798828125,
0.0005731582641601562
] |
In this method, thermal energy is imparted to the product via hot air, facilitating moisture removal through the process of convection. A notable limitation of this technique is the comparatively extended duration required for effective drying. Furthermore, the direct application of heat can potentially compromise the quality of the product .
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39057497_p11
|
39057497
|
sec[2]/sec[0]/sec[1]/p[0]
|
3.1.2. Freeze-Drying
| 3.716797 |
biomedical
|
Other
|
[
0.98291015625,
0.0013723373413085938,
0.015655517578125
] |
[
0.01593017578125,
0.9765625,
0.007389068603515625,
0.0002694129943847656
] |
Freeze-drying is a dehydration process conducted at low temperatures. This technique involves freezing the material and subsequently removing its moisture content through the sublimation of ice. Freeze-drying is favored over conventional heat-drying and evaporation methods due to the superior quality of the resultant samples. The primary advantage of this method is its ability to preserve the shape of the sample, which is largely attributed to the low-temperature processing conditions .
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39057497_p12
|
39057497
|
sec[2]/sec[0]/sec[2]/p[0]
|
3.1.3. Room Temperature
| 4.070313 |
biomedical
|
Study
|
[
0.99951171875,
0.0001176595687866211,
0.0005221366882324219
] |
[
0.99560546875,
0.0021457672119140625,
0.0021305084228515625,
0.00006014108657836914
] |
Room temperature drying is a simple and cost-effective method for drying bacterial cellulose, involving exposure to ambient air until constant weight is achieved. Moisture loss is measured by the difference in mass before and after drying. This method can cause structural changes in porosity and density due to atmospheric pressure. Comparative studies show similar crystallinity between room temperature and freeze-dried samples (71% and 76%, respectively). Room temperature drying results in thinner films and higher fiber density compared to freeze-drying at −80 °C .
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39057497_p13
|
39057497
|
sec[2]/sec[0]/sec[3]/p[0]
|
3.1.4. Supercritical CO 2 Drying
| 3.142578 |
biomedical
|
Other
|
[
0.95947265625,
0.0003859996795654297,
0.040374755859375
] |
[
0.46630859375,
0.52294921875,
0.01019287109375,
0.00046324729919433594
] |
Supercritical CO 2 drying, or critical point drying, removes moisture using CO 2 at 74 bar and above 31 °C. In this supercritical state, CO 2 penetrates samples effectively, making the process faster than other methods. CO 2 can be recycled, enhancing energy efficiency and sustainability. Researchers have used this method to study bacterial cellulose drying, comparing it with freeze-drying and room temperature drying .
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
39057497_p14
|
39057497
|
sec[2]/sec[0]/sec[4]/p[0]
|
3.1.5. Microwave Drying
| 4.003906 |
biomedical
|
Study
|
[
0.9990234375,
0.00011533498764038086,
0.0010671615600585938
] |
[
0.9873046875,
0.0032196044921875,
0.009307861328125,
0.00007218122482299805
] |
Several researchers have employed microwave ovens, traditionally used for cooking, to dry bacterial cellulose. This technique, which is also prevalent in the food industry for drying vegetables and fruits, uses high-frequency electromagnetic waves in the range of 300 MHz to 300 GHz. It is regarded as an energy-efficient method. Microwave drying shortens processing time by converting the absorbed electromagnetic waves into heat, which facilitates the evaporation of moisture within the material . Compared to hot air oven drying, microwave drying yields a smoother bacterial cellulose surface. This smoothness results from the even heat distribution throughout the structure due to water molecule vibrations. In contrast, hot air drying can cause surface wrinkles due to rapid water evaporation .
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999998 |
39057497_p15
|
39057497
|
sec[2]/sec[0]/sec[5]/p[0]
|
3.1.6. Bidirectional Freezing
| 4.300781 |
biomedical
|
Study
|
[
0.9970703125,
0.0003371238708496094,
0.002445220947265625
] |
[
0.9990234375,
0.00025343894958496094,
0.0007276535034179688,
0.000049054622650146484
] |
Directional freezing involves freezing from one direction to produce clear ice. In a domestic freezer, this can be performed by placing water in an insulated container, allowing it to freeze from the top down. The container is removed before fully frozen to avoid mineral incorporation . However, the bidirectional freezing technique organizes small constituents, including ceramic particles, platelets, and polymers, into a large-scale, single-domain porous lamellar structure measuring in the centimeter range. This structure is analogous to natural nacre, albeit lacking the “mortar” component . The bidirectional freezing technique is an advanced method for creating anisotropic porous structures with specialized spatial arrangements. According to Zhu et al., they synthesized the aerogel via bidirectional freezing, incorporating PVA (polyvinyl alcohol) and BC as the matrix and Ti 3 C 2 MXene as the filler for enhanced thermal conductivity. A wedge-shaped PDMS (Polydimethylsiloxane) structure induced temperature gradients in both vertical and horizontal directions, thereby regulating ice crystal formation during the freezing process. The microstructural characteristics and thermophysical properties of the aerogels were systematically investigated by varying the PDMS wedge angle from 0° to 30°. The resulting BC/PVA/MXene (BPM) aerogels demonstrated promising applications in photothermal harvesting and conversion, particularly in solar thermal systems. In Figure 4 is an illustration of the preparation process of BPM aerogel and BG PCM [(BPM/PEG (polyethylene glycol)) phase change material]. According to the study, anisotropic PCM composites made with a bidirectional freezing process have good thermal conductivity, photothermal conversion, and storage properties. This approach uses simultaneous temperature gradients in both horizontal and vertical directions, with the long-range aligned structure acting as a directional heat transport channel. Bidirectional aligned PCMs with temperature gradients of 0° and 20° exhibit high thermal conductivities of 0.716 W m −1 K −1 and 0.768 W m −1 K −1 , which are 184% greater than PEG. They also show photothermal conversion efficiencies of 55.17% and 76.91 percent. Furthermore, the vertically oriented pore structure confines the PEG, resulting in form durability and a high enthalpy of 157.7 J/g .
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999997 |
39057497_p16
|
39057497
|
sec[2]/sec[0]/sec[6]/p[0]
|
3.1.7. Oven Drying
| 4.136719 |
biomedical
|
Study
|
[
0.9990234375,
0.00019848346710205078,
0.0009322166442871094
] |
[
0.99951171875,
0.00019669532775878906,
0.0004494190216064453,
0.00003343820571899414
] |
The oven-drying method, a thermo-gravimetric process involving consistent temperature drying for a set duration, is commonly employed to assess moisture content in materials by comparing original and dried weights . This method’s straightforward application makes it widely favored for drying bacterial cellulose. Florentina Sederaviciute et al. utilized this method to investigate the drying effects on the mechanical properties of cellulose films produced from kombucha-derived G. bacter xylinus in a tea medium. Following neutralization with distilled water and gentle tissue paper pressing, the cellulose films were dried at temperatures of 25 °C, 50 °C, and 75 °C. Results showed that higher temperatures led to quicker and more significant moisture loss, with losses recorded as 91.8% at 50 °C and 88.3% at 75 °C during the specified drying period .
|
[
"Sebnem Sozcu",
"Jaroslava Frajova",
"Jakub Wiener",
"Mohanapriya Venkataraman",
"Blanka Tomkova",
"Jiri Militky"
] |
https://doi.org/10.3390/gels10070474
|
N/A
|
https://creativecommons.org/licenses/by/4.0/
|
en
| 0.999996 |
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