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Authors = Jorge Abad ORCID = 0000-0003-1571-9846

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11 pages, 4661 KiB  
Article
Somatic Embryogenesis in Native Peruvian Fine-Flavor Cocoa Genotypes
by Karol Rubio, Santos Leiva, Manuel Oliva, Jorge R. Diaz-Valderrama and Juan Carlos Guerrero-Abad
Int. J. Plant Biol. 2025, 16(3), 84; https://doi.org/10.3390/ijpb16030084 - 1 Aug 2025
Viewed by 92
Abstract
Cacao genotypes propagation through plant tissue culture represents a strategic approach for establishing a core collection of elite plants to be used as a donor material source, necessary for increasing new planting areas of cacao. This study aimed to evaluate somatic embryo regeneration [...] Read more.
Cacao genotypes propagation through plant tissue culture represents a strategic approach for establishing a core collection of elite plants to be used as a donor material source, necessary for increasing new planting areas of cacao. This study aimed to evaluate somatic embryo regeneration in ten native fine-aroma cacao genotypes (INDES-06, INDES-11, INDES-14, INDES-32, INDES-52, INDES-53, INDES-63, INDES-64, INDES-66, INDES-70) from the INDES-CES germplasm collection, under in vitro conditions using culture medium supplemented with different concentrations of Thidiazuron (0, 10, and 20 nM). Our results showed an average of 20 and 100% of callogenesis in all genotypes evaluated, but the callus development did not appear after early stages of its induction; however, primary somatic embryos were observed after 42 days after TDZ treatment in the INDES-52, INDES-53, INDES-64, INDES-66, INDES-70 genotypes. The INDES-52 genotype was more responsive to under 20 nM of TDZ, generating an average of 17 embryos per explant. This study contributes to the adaptation and establishment of a protocol for somatic embryo regeneration of fine-flavor cacao genotypes. Full article
(This article belongs to the Section Plant Reproduction)
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11 pages, 239 KiB  
Article
Targeted Antibiotic Prophylaxis in Percutaneous Nephrolithotomy: Results of a Protocol Based on Preoperative Urine Culture and Risk Assessment
by Felipe Osorio-Ospina, Gonzalo Bueno-Serrano, María Pilar Alcoba-García, Juan Tabares-Jiménez, Blanca Gómez-Jordana-Mañas, Elena García-Criado, Joaquin Ruiz-de-Castroviejo, Xabier Pérez-Aizpurua, Jaime Jorge Tufet-I-Jaumot, Raúl González-Páez, Jose Carlos Matta-Pérez, Beatriz Yanes-Glaentzlin, Juan Francisco Jiménez-Abad, José Maria Alcázar Peral, Nerea Carrasco Antón, Elizabet Petkova-Saiz and Carmen González-Enguita
J. Clin. Med. 2025, 14(15), 5249; https://doi.org/10.3390/jcm14155249 - 24 Jul 2025
Viewed by 472
Abstract
Background: Infectious complications are common after percutaneous nephrolithotomy (PCNL). Clinical guidelines recommend, previous to surgery, prolonged antibiotic regimens in patients with preoperative positive urine cultures to reduce infectious risk. However, such strategies may increase selective pressure and promote antimicrobial resistance. Evidence supporting the [...] Read more.
Background: Infectious complications are common after percutaneous nephrolithotomy (PCNL). Clinical guidelines recommend, previous to surgery, prolonged antibiotic regimens in patients with preoperative positive urine cultures to reduce infectious risk. However, such strategies may increase selective pressure and promote antimicrobial resistance. Evidence supporting the use of a single antibiotic dose tailored to culture sensitivity in these cases is limited but emerging. Methods: We conducted a retrospective observational study including 187 PCNL procedures performed between 2021 and 2023 under an individualized antibiotic prophylaxis protocol. Patients with negative or contaminated urine cultures received a single empirical dose, while those with recent positive cultures received a single dose based on antimicrobial susceptibility testing. Postoperative complications—including fever, sepsis, and a composite outcome—were analyzed through multivariable logistic regression, comparing high- and low-risk patients. Results: A total of 67.9% of procedures were performed in patients meeting at least one high-risk criterion, including a positive preoperative urine culture in 32.1%. The overall incidence of infectious complications was 11.9% (fever 8.7%, sepsis 3.2%), with no significant differences between risk groups. A low concordance was observed between preoperative and intraoperative urine cultures (Spearman = 0.3954). Conclusions: A single preoperative antibiotic dose adjusted to the antibiogram, even in patients with a positive urine culture, was not associated with increased infectious complications. This approach is an initial step that supports a rational and individualized prophylactic strategy aligned with the goals of antimicrobial stewardship programs (ASPs). Full article
(This article belongs to the Special Issue Targeted Treatment of Kidney Stones)
11 pages, 3472 KiB  
Case Report
The Use of a Digitally Generated Matrix for Consistent Shade Recording in Tooth Bleaching—A Case Report
by Cristian Abad-Coronel, Guissell Vallejo-Yupa, Paulina Aliaga, Nancy Mena-Córdova, Jorge Alonso Pérez-Barquero and José Amengual-Lorenzo
Dent. J. 2025, 13(8), 339; https://doi.org/10.3390/dj13080339 - 24 Jul 2025
Viewed by 244
Abstract
Objectives: The aim of this study was to evaluate the effectiveness of spectrophotometers for objective tooth color measurement, particularly in bleaching procedures enhanced by digital positioning templates. Methods: Tooth color registration was conducted using both subjective methods with shade guides and objective methods [...] Read more.
Objectives: The aim of this study was to evaluate the effectiveness of spectrophotometers for objective tooth color measurement, particularly in bleaching procedures enhanced by digital positioning templates. Methods: Tooth color registration was conducted using both subjective methods with shade guides and objective methods with spectrophotometers. Spectrophotometers were chosen for their ability to provide objective, quantifiable, and reproducible results, crucial for monitoring color modifications accurately. Digital workflows were implemented to enhance the registration process further. These workflows included providing a precise positioning matrix for spectrophotometer sensors and optimizing working models to ensure high-quality therapeutic splints. Results: The use of spectrophotometers demonstrated superior performance in registering tooth color objectively compared to subjective shade guides. Digital workflows significantly improved the precision and efficiency of spectrophotometer measurements through a digital matrix, enhancing the quality of therapeutic splints obtained. Conclusions: Spectrophotometers are recommended for objective and precise tooth color registration, particularly in bleaching procedures. Integrating a digital positioning matrix enhances measurement accuracy and reliability, supporting effective monitoring and treatment outcomes. Full article
(This article belongs to the Special Issue New Trends in Digital Dentistry)
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16 pages, 679 KiB  
Article
Pharmacogenetic Biomarkers of Ibrutinib Response and Toxicity in Chronic Lymphocytic Leukemia: Insights from an Observational Study
by Noelia Pérez-Gómez, Antonio Sanz-Solas, Beatriz Cuevas, María Victoria Cuevas, Cristina Alonso-Madrigal, Javier Loscertales, Rodolfo Álvarez-Nuño, Covadonga García, Pablo Zubiaur, Gonzalo Villapalos-García, Raúl Miguel Parra-Garcés, Gina Mejía-Abril, Raquel Alcaraz, Raquel Vinuesa, Francisco Javier Díaz-Gálvez, María González-Oter, Natalia García-Sancha, Raúl Azibeiro-Melchor, Tomás José González-López, Francisco Abad-Santos, Jorge Labrador and Miriam Saiz-Rodríguezadd Show full author list remove Hide full author list
Pharmaceuticals 2025, 18(7), 996; https://doi.org/10.3390/ph18070996 - 2 Jul 2025
Viewed by 425
Abstract
Background/Objectives: Ibrutinib is a selective Bruton’s tyrosine kinase inhibitor approved for the treatment of chronic lymphocytic leukemia (CLL). This drug exhibits significant variability in response and toxicity profile, possibly due to genetic polymorphisms in drug-metabolizing enzymes and transporters. The aim of this observational [...] Read more.
Background/Objectives: Ibrutinib is a selective Bruton’s tyrosine kinase inhibitor approved for the treatment of chronic lymphocytic leukemia (CLL). This drug exhibits significant variability in response and toxicity profile, possibly due to genetic polymorphisms in drug-metabolizing enzymes and transporters. The aim of this observational study is to address interindividual variability in the efficacy and safety of ibrutinib treatment in 49 CLL patients. Methods: Genotyping of nine polymorphisms was performed by quantitative polymerase chain reaction (qPCR) using a ViiA7® PCR Instrument and TaqMan assays, and ibrutinib plasma concentrations were determined using high-performance liquid chromatography coupled to a tandem mass spectrometry detector (HPLC-MS/MS). Results: Our study confirmed a high response rate, with 62% of patients achieving complete remission (CR), 9% CR with incomplete hematologic recovery (CRi), and 24% partial remission (PR). The impact of genetic polymorphisms on the CR rate was evaluated, revealing no statistically significant associations for CYP3A4, CYP3A5, ABCB1, ABCG2, and SLCO1B1 variants. However, a tendency was observed for patients carrying ABCB1 rs1128503, rs1045642 T/T, or rs2032582 A/A genotypes to achieve a higher CR rate. Adverse drug reactions (ADRs) were frequent, with vascular disorders (39%) and infections (27%) being the most common. Genetic polymorphisms influenced ibrutinib toxicity, with CYP3A4 *1/*22 appearing to be protective against overall ADRs. Conclusions: The unexpected association between CYP3A4 *1/*22 genotype and lower ADR incidence, as well as the trend toward improved treatment response in patients carrying ABCB1 genotypes, suggests compensatory metabolic mechanisms. However, given the small sample size, larger studies are needed to confirm these findings and their clinical implications, while also aiming to uncover other non-genetic factors that may contribute to a better understanding of the variability in treatment response and toxicity. Full article
(This article belongs to the Special Issue Therapeutic Drug Monitoring and Adverse Drug Reactions: 2nd Edition)
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20 pages, 509 KiB  
Article
Nursing Students’ Perceptions of Clinical Debriefing TALK©: A Qualitative Case Study
by Belén González-Tejerina, Jorge Pérez-Corrales, Domingo Palacios-Ceña, Jose Abad-Valle, Paloma Rodríguez Gómez, Beatriz González-Toledo, Eva García-Carpintero Blas and Marta Garrigues-Ramón
Nurs. Rep. 2025, 15(6), 194; https://doi.org/10.3390/nursrep15060194 - 30 May 2025
Viewed by 798
Abstract
Background/Objectives: Clinical debriefing is a learning tool that promotes reflection after critical incidents, improving patient safety and professional performance. TALK© is a debriefing technique designed to facilitate structured team self-reflection after any learning event in clinical settings. The aim of this study [...] Read more.
Background/Objectives: Clinical debriefing is a learning tool that promotes reflection after critical incidents, improving patient safety and professional performance. TALK© is a debriefing technique designed to facilitate structured team self-reflection after any learning event in clinical settings. The aim of this study is to explore the experiences of fourth-year nursing students in clinical internships with clinical debriefing guided by the TALK© tool. Methods: A qualitative case study was conducted. Twenty-seven participants were recruited using purposeful sampling. The sample consisted of nursing students. Data were collected through in-depth interviews, focus groups, personal writings, and researcher field notes. An inductive thematic analysis process was applied. The data analysis was performed using ATLAS.ti 23 software, which facilitated the identification and organization of key themes and patterns within the qualitative data. Conclusions: Participants perceived TALK©-guided clinical debriefing as a valuable practice. Key factors influencing their experience included the reflexive process, the debriefing approach and technique, the timing and context, as well as its emotional sphere. Full article
(This article belongs to the Section Nursing Education and Leadership)
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13 pages, 1768 KiB  
Article
Direct Measurement of the Ciliary Sulcus Diameter Using Optical Coherence Tomography—Inter-Rater Variability
by Timo Eppig, Manuel Seer, Antonio Martinez-Abad, Virgilio Galvis, Saskia Schütz, Alejandro Tello, Michiel C. Rombach and Jorge L. Alió
Sensors 2024, 24(21), 6950; https://doi.org/10.3390/s24216950 - 29 Oct 2024
Cited by 1 | Viewed by 1652
Abstract
The determination of sulcus-to-sulcus measurements has been challenging due to the limitations of current approaches. Ultrasound methods are highly operator-dependent and require extensive training, while traditional optical devices cannot visualize structures posterior to the iris. However, modern optical anterior segment coherence tomography (AS-OCT) [...] Read more.
The determination of sulcus-to-sulcus measurements has been challenging due to the limitations of current approaches. Ultrasound methods are highly operator-dependent and require extensive training, while traditional optical devices cannot visualize structures posterior to the iris. However, modern optical anterior segment coherence tomography (AS-OCT) devices are changing this paradigm by identifying some anatomical landmarks posterior to the iris. This study evaluates the reproducibility of optical sulcus measurements in the context of sizing a novel accommodative intraocular lens (IOL). Preoperative OCT scans of patients scheduled for cataract surgery were analyzed regarding the dimensions of the ciliary sulcus using a custom scan method with a clinically available anterior segment optical coherence tomographer. Measurements were compared between two different readers, and various derived parameters were compared. The measurements by both readers were highly correlated (R2 > 0.96), and their agreement was excellent (mean difference 0.02 mm with 95% limits of agreement from −0.11 to 0.15 mm). In contrast, the sulcus diameter measurement did not agree well with automatically calculated values, such as the anterior chamber width or white-to-white. This leads to the conclusion that modern swept-source AS-OCT measurements of the ciliary sulcus dimensions are feasible, reproducible, and may be a clinically useful tool. Full article
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9 pages, 894 KiB  
Article
In Vitro Shoot Regeneration and Multiplication of Peruvian Rocoto Chili Pepper (Capsicum pubescens Ruiz & Pav.)
by Angel David Hernández-Amasifuen, Alexandra Jherina Pineda-Lázaro, Jorge L. Maicelo-Quintana and Juan Carlos Guerrero-Abad
Int. J. Plant Biol. 2024, 15(4), 979-987; https://doi.org/10.3390/ijpb15040069 - 4 Oct 2024
Cited by 1 | Viewed by 2144
Abstract
The rocoto (Capsicum pubescens Ruiz & Pav.) (Solanaceae) is an endemic herbaceous chili pepper from Peru. Low yields of rocoto production are due to the low availability of certified seeds or the production of superior plant seedlings. Therefore, the present study aimed [...] Read more.
The rocoto (Capsicum pubescens Ruiz & Pav.) (Solanaceae) is an endemic herbaceous chili pepper from Peru. Low yields of rocoto production are due to the low availability of certified seeds or the production of superior plant seedlings. Therefore, the present study aimed to establish an in vitro protocol for the regeneration and multiplication of rocoto shoots. The multiplication was carried out on shoot tips excised from rocoto seedlings germinated under in vitro conditions, and then the explants were placed on Murashigue and Skoog (MS) medium supplemented with different concentrations of 6-benzylaminopurine (BAP) and Kinetin: 0.5, 1.0, 1.5 and 2.0 mg/L. For rooting, shoots were obtained from the multiplication phase and placed under different treatments made up of MS medium supplemented with different concentrations of indole butyric acid (IBA) and naphthalene acetic acid (NAA): 0.5, 1.0, 1.5 and 2.0 mg/L. In the multiplication phase, the best results were observed with MS medium supplemented with 1.0 mg/L BAP, with 82.22% shoot development, 2.93 shoots per explant and 2.75 cm shoot length. In the rooting phase, the best results were observed with MS medium supplemented with 1.5 mg/L IBA, with 91.11% root development, 9.73 roots per explant and 6.79 cm root length. Here, we show the first evidence and tool for the in vitro regeneration and multiplication of rocoto chili pepper, which could be used for the multiplication of superior genotypes, germplasm in vitro conservation and its use in plant breeding programs. Full article
(This article belongs to the Section Plant Reproduction)
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10 pages, 1201 KiB  
Article
Optical Genome Mapping as a New Tool to Overcome Conventional Cytogenetics Limitations in Patients with Bone Marrow Failure
by June Iriondo, Ana Gómez, Josune Zubicaray, Jorge Garcia-Martinez, Lorea Abad, Carmen Matesanz, Reyes Giménez, Almudena Galán, Alejandro Sanz, Elena Sebastián, Jesús González de Pablo, Ana de la Cruz, Manuel Ramírez and Julián Sevilla
Genes 2024, 15(5), 559; https://doi.org/10.3390/genes15050559 - 27 Apr 2024
Viewed by 1739
Abstract
Cytogenetic studies are essential in the diagnosis and follow up of patients with bone marrow failure syndromes (BMFSs), but obtaining good quality results is often challenging due to hypocellularity. Optical Genome Mapping (OGM), a novel technology capable of detecting most types chromosomal structural [...] Read more.
Cytogenetic studies are essential in the diagnosis and follow up of patients with bone marrow failure syndromes (BMFSs), but obtaining good quality results is often challenging due to hypocellularity. Optical Genome Mapping (OGM), a novel technology capable of detecting most types chromosomal structural variants (SVs) at high resolution, is being increasingly used in many settings, including hematologic malignancies. Herein, we compared conventional cytogenetic techniques to OGM in 20 patients with diverse BMFSs. Twenty metaphases for the karyotype were only obtained in three subjects (15%), and no SVs were found in any of the samples. One patient with culture failure showed a gain in chromosome 1q by fluorescence in situ hybridization, which was confirmed by OGM. In contrast, OGM provided good quality results in all subjects, and SVs were detected in 14 of them (70%), mostly corresponding to cryptic submicroscopic alterations not observed by standard techniques. Therefore, OGM emerges as a powerful tool that provides complete and evaluable results in hypocellular BMFSs, reducing multiple tests into a single assay and overcoming some of the main limitations of conventional techniques. Furthermore, in addition to confirming the abnormalities detected by conventional techniques, OGM found new alterations beyond their detection limits. Full article
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13 pages, 9858 KiB  
Article
Comparative Study of the Influence of Heat Treatment on Fracture Resistance of Different Ceramic Materials Used for CAD/CAM Systems
by Andrea Ordoñez Balladares, Cristian Abad-Coronel, Joao Carlos Ramos, Jorge I. Fajardo, Cesar A. Paltán and Benjamín José Martín Biedma
Materials 2024, 17(6), 1246; https://doi.org/10.3390/ma17061246 - 8 Mar 2024
Cited by 4 | Viewed by 2603
Abstract
The aim of this study was to compare the influence of heat treatment on fracture resistance (FR) of different ceramic materials used for CAD/CAM systems. Methods: Eighty monolithic restorations were designed using the same parameters and milled with a CAD/CAM system (CEREC SW [...] Read more.
The aim of this study was to compare the influence of heat treatment on fracture resistance (FR) of different ceramic materials used for CAD/CAM systems. Methods: Eighty monolithic restorations were designed using the same parameters and milled with a CAD/CAM system (CEREC SW 5.0, PrimeMill, Dentsply-Sirona™, Bensheim, Germany), forming five study groups: Group 1 (n = 10), CEREC Tessera (Dentsply-Sirona™, Bensheim, Germany) crystallized (CCT), Group 2 (n = 10), CEREC Tessera uncrystallized (UCT), Group 3 (n = 20), Emax-CAD (Ivoclar Vivadent, Schaan, Liechtenstein) (CEC), Group 4 (n = 20), Vita Suprinity (Vita Zahnfabrik, Bad Säckingen, Germany) (CVS), and Group 5 (n = 20) Cameo (Aidite, Qinhuangdao, China) (CC). Results: The average FR was similar for CCT, CC, and CEC at above 400 N, while CVS and UCT had the lowest values at 389,677 N and 343,212 N, respectively. Conclusion: Among the three ceramic materials that exhibited an FR above 400 N, CCT was considered the first recommended choice for CAD/CAM systems. This material not only demonstrated the highest FR but also exhibited outstanding consistency in the related measurements without the presence of outliers. Although the CC material showed high FR, its high dispersion revealed inconsistencies in the repetitions, suggesting caution in its use. Full article
(This article belongs to the Special Issue Characteristics of Dental Ceramics)
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8 pages, 610 KiB  
Article
Clinical Evaluation of a New Spectral-Domain Optical Coherence Tomography-Based Biometer
by Jorge L. Alió, Marina José-Martínez, Antonio Martínez-Abad, Alejandra E. Rodríguez, Francesco Versaci, Jesper Hjortdal, Joaquim Neto Murta, Ana B. Plaza-Puche, Mario Cantó-Cerdán and David P. Piñero
Diagnostics 2024, 14(5), 560; https://doi.org/10.3390/diagnostics14050560 - 6 Mar 2024
Cited by 1 | Viewed by 1831
Abstract
The VEMoS-AXL system is a new optical biometer based on spectral domain optical coherence tomography (SD-OCT) that has been tested in terms of intrasession repeatability and compared with a swept-source optical coherence tomography biometer (SS-OCT), which is recognized as the gold standard for [...] Read more.
The VEMoS-AXL system is a new optical biometer based on spectral domain optical coherence tomography (SD-OCT) that has been tested in terms of intrasession repeatability and compared with a swept-source optical coherence tomography biometer (SS-OCT), which is recognized as the gold standard for the performance of an agreement analysis. A biometric analysis was performed three consecutive times in 120 healthy eyes of 120 patients aged between 18 and 40 years with the SD-OCT system, and afterwards, a single measurement was obtained with the SS-OCT system. Within-subject standard deviations were 0.004 mm, 4.394 µm, and 0.017 mm for axial length (AL), central corneal thickness (CCT), and anterior chamber depth (ACD) measures obtained with the SD-OCT biometer, respectively. The agreement between devices was good for AL (limits of agreement, LoA: −0.04 to 0.03 mm) and CCT (LoA: −4.36 to 14.38 µm), whereas differences between devices were clinically relevant for ACD (LoA: 0.03 to 0.21 mm). In conclusion, the VEMoS-AXL system provides consistent measures of anatomical parameters, being most of them interchangeable with those provided by the SS-OCT-based gold standard. Full article
(This article belongs to the Special Issue Optical Coherence Tomography (OCT) Imaging in Ophthalmology)
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15 pages, 1132 KiB  
Article
Uncertainty Observer-Based Control for a Class of Fractional- Order Non-Linear Systems with Non-Linear Control Inputs
by Juan Javier Montesinos-García, Jorge Luis Barahona-Avalos, Jesús Linares-Flores and José Antonio Juárez-Abad
Fractal Fract. 2023, 7(12), 836; https://doi.org/10.3390/fractalfract7120836 - 25 Nov 2023
Cited by 1 | Viewed by 1537
Abstract
This paper presents a novel control strategy based on an uncertainty estimator for a class of fractional-order nonlinear systems characterized by a polynomial input. The proposed strategy allows the system to be controlled without resorting to transformations or approximate linearization. This is accomplished [...] Read more.
This paper presents a novel control strategy based on an uncertainty estimator for a class of fractional-order nonlinear systems characterized by a polynomial input. The proposed strategy allows the system to be controlled without resorting to transformations or approximate linearization. This is accomplished by using a fractional-order sliding-mode observer, whose task is to estimate certain portions of the state of the nonlinear system of a non-integer order, thus allowing the control law to counteract these elements to steer the system towards a desired behavior. To validate the performance of the proposed strategy, it was implemented, both in simulation and experimentally, to regulate the temperature of the cold side of a thermoelectric module fed by a DC/DC electronic power converter of the step-down type, a system that is known to have a nonlinear polynomial-type control input. Full article
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15 pages, 3155 KiB  
Article
Comparative Analysis of the Structural Weights of Fixed Prostheses of Zirconium Dioxide, Metal Ceramic, PMMA and 3DPP Printing Resin—Mechanical Implications
by Cristian Abad-Coronel, David Vélez Chimbo, Billy Lupú, Miguel Pacurucu, Marco V. Fárez and Jorge I. Fajardo
Dent. J. 2023, 11(11), 249; https://doi.org/10.3390/dj11110249 - 26 Oct 2023
Cited by 8 | Viewed by 3671
Abstract
The aim of this study was to determine the mechanical implications of four-unit fixed dental prostheses (FDPs) made of (1) monolithic zirconium dioxide (ZR O2), (2) polymethylmethacrylate (PMMA), (3) metal ceramic (PFM) and (4) impression resin (3DPP). Methods: Four groups were [...] Read more.
The aim of this study was to determine the mechanical implications of four-unit fixed dental prostheses (FDPs) made of (1) monolithic zirconium dioxide (ZR O2), (2) polymethylmethacrylate (PMMA), (3) metal ceramic (PFM) and (4) impression resin (3DPP). Methods: Four groups were studied with eight samples for each material (n: 32). Each structure was weighed, subjected to compressive tests and analyzed using 3D FEA. Results: PMMA presented the lowest structural weight (1.33 g), followed by 3DPP (1.98 g), ZR O2 (6.34 g) and PFM (6.44 g). In fracture tests, PMMA presented a compressive strength of 2104.73 N and a tension of 351.752 MPa; followed by PFM, with a strength of 1361.48 N and a tension of 227.521 MPa; ZR O2, with a strength of 1107.63 N and a tension of 185.098 MPa; and 3DPP, with a strength of 1000.88 N and a tension of 143.916 MPa. According to 3D FEA, 3DPP presented the lowest degree of deformation (0.001 mm), followed by PFM (0.011 mm), ZR O2 (0.168 mm) and PMMA (1.035 mm). Conclusions: The weights of the materials did not have a direct influence on the mean values obtained for strength, stress or strain. Since the performance was related to the tension and forces supported by the structures in critical zones, the importance of considering design factors is clear. In vitro and 3D FEA assays allowed us to simulate different scenarios for the mechanical properties of certain materials before evaluating them clinically. Thus, they can generate predictions that would allow for the design of a better research methodology in future clinical trials. Full article
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14 pages, 7858 KiB  
Article
Comparative Analysis of the Fracture Resistance of a Polymeric Material for 3D Printing and a Milled Polymethylmethacrylate Material as Interim Material for Fixed Partial Dentures: New Material Updated
by Cristian Abad-Coronel, Johanna Córdova, Andrea Merchán, Jaime Larriva, Ariana Bravo, Bryam Bernal, Cesar A. Paltán and Jorge I. Fajardo
Designs 2023, 7(5), 118; https://doi.org/10.3390/designs7050118 - 13 Oct 2023
Cited by 2 | Viewed by 3607
Abstract
The aim of this study was to evaluate and compare the fracture resistance of a temporary three-unit fixed dental prosthesis (FDP) made of a new polymeric material obtained by an additive technique (3DPP) using a computer-aided design and manufacturing (CAD/CAM) system, comparing the [...] Read more.
The aim of this study was to evaluate and compare the fracture resistance of a temporary three-unit fixed dental prosthesis (FDP) made of a new polymeric material obtained by an additive technique (3DPP) using a computer-aided design and manufacturing (CAD/CAM) system, comparing the prosthesis to the respective outcomes of temporary polymethylmethacrylate (PMMA) FDPs obtained by a subtractive technique (milling). Methods: Three-unit FDPs were 3D printed using a polymeric material (n = 20) or milled using polymethylmethacrylate (n = 20). After thermocycling at 5000 cycles at extreme temperatures of 5 °C and 55 °C in distilled water, each specimen was subjected to a compression test on a universal testing machine at a rate of 0.5 mm/min until failure occurred, recording the value in newtons (N). Results: There were statistically significant differences (p-value < 0.005) between the PMMA material (2104.7 N; SD = 178.97 N) and 3DPP (1000.8 N; SD = 196.4 N). Conclusions: The fracture resistance of the PDFs manufactured from milled PMMA showed higher values for fracture resistance. However, the resistance of the 3DPP showed acceptable values under mechanical load; this notable advance in the resistance of printed materials consolidates them as an important alternative to use in interim indirect restorations. Full article
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21 pages, 12143 KiB  
Article
Coherent Structures Analysis of Methanol and Hydrogen Flames Using the Scale-Adaptive Simulation Model
by José A. Parra Rodríguez, Marco A. Abad Romero, Oliver M. Huerta Chávez, Luis R. Rangel-López, José C. Jiménez-Escalona and Jorge Diaz Salgado
Energies 2023, 16(20), 7074; https://doi.org/10.3390/en16207074 - 13 Oct 2023
Cited by 1 | Viewed by 1237
Abstract
Computational fluid dynamics techniques were applied to reproduce the characteristics of the liquid methanol burner described in a previous paper by Guevara et al. In this work, the unstable Reynolds-averaged Navier–Stokes (U-RANS) approach known as the Scale-Adaptive Simulation (SAS) model was employed, together [...] Read more.
Computational fluid dynamics techniques were applied to reproduce the characteristics of the liquid methanol burner described in a previous paper by Guevara et al. In this work, the unstable Reynolds-averaged Navier–Stokes (U-RANS) approach known as the Scale-Adaptive Simulation (SAS) model was employed, together with the steady nonadiabatic flamelets combustion model, to characterize and compare methanol and hydrogen flames. These flames were compared to determine whether this model can reproduce the coherent dynamic structures previously obtained using the LES model in other investigations. The LES turbulence model still entails a very high computational cost for many research centers. Conversely, the SAS model allows for local activation and amplification, promoting the transitions of momentum equations from the stationary to the transient mode and leading to a dramatic reduction in computational time. It was found that the global temperature contour of the hydrogen flame was higher than that of methanol. The air velocity profile peaks in the methanol flame were higher than those in hydrogen due to the coherent structures formed in the near field of atomization. Both flames presented coherent structures in the form of PVC; however, in the case of hydrogen, a ring-type vortex surrounding the flame was also developed. The axial, tangential, and radial velocity profiles of the coherent structures along the axial axis of the combustion chamber were analyzed at a criterion of Q = 0.003. The investigation revealed that the radial and tangential components had similar behaviors, while the axial velocity components differed. Finally, it was found that, using the SAS model, the coherent dynamic structures of the methanol flame were different from those obtained in previous works using the LES model. Full article
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14 pages, 1940 KiB  
Article
Comparative Analysis between Conventional Acrylic, CAD/CAM Milled, and 3D CAD/CAM Printed Occlusal Splints
by Cristian Abad-Coronel, Carolina Ruano Espinosa, Sofía Ordóñez Palacios, César A. Paltán and Jorge I. Fajardo
Materials 2023, 16(18), 6269; https://doi.org/10.3390/ma16186269 - 19 Sep 2023
Cited by 12 | Viewed by 3757
Abstract
The development of digital technologies has allowed for the fabrication of new materials; however, it makes it difficult to choose the best methods to obtain occlusal splints with optimal properties, so it is essential to evaluate the effectiveness of these materials. The aim [...] Read more.
The development of digital technologies has allowed for the fabrication of new materials; however, it makes it difficult to choose the best methods to obtain occlusal splints with optimal properties, so it is essential to evaluate the effectiveness of these materials. The aim of the study is to compare the fracture resistance of occlusal splints made of different materials after thermo-mechanical aging. Methods: A total of 32 samples were made from 4 materials (two 3D printed polymeric materials, a PMMA disc for CAD/CAM, and a conventional heat-cured acrylic resin); subsequently, the fracture test was performed using the load compression mode applied occlusally on the splint surface. Statistical analysis: Four statistical tests were used (Shapiro-Wilk, Levene’s test, ANOVA, and Tukey’s HSD test). Results: The following study showed that there are differences in fracture strength among the four materials investigated, where the highest strength was observed in the milled splint, with a mean of 3051.2 N (newton) compared to the strength of the flexible splint with 1943.4 N, the printed splint with 1489.9 N, and the conventional acrylic splint with 1303.9 N. Conclusions: The milled splints were the most resistant to fracture. Of the printed splints, the splint made with flexural rigid resin withstood the applied forces in acceptable ranges, so its clinical indication may be viable. Although the results of this research indicated differences in the mechanical properties between the CAD/CAM and conventional fabrication methods, the selection may also be influenced by processing time and cost, since with a CAD/CAM system there is a significant reduction in the production time of the splint material. Full article
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