Abstract: Antibiotic resistance is driven by selection, but the degree to which a bacterial strain’s evolutionary history shapes the mechanism and strength of resistance remains an open question. Here, we reconstruct the genetic and evolutionary mechanisms of carbapenem resistance in a clinical isolate of Klebsiella quasipneumoniae. A combination of short- and long-read sequencing, machine learning, and genetic and enzymatic analyses established that this carbapenem-resistant strain carries no carbapenemase-encoding genes. Genetic reconstruction of the resistance phenotype confirmed that two distinct genetic loci are necessary in order for the strain to acquire carbapenem resistance. Experimental evolution of the carbapenem-resistant strains in growth conditions without the antibiotic revealed that both loci confer a significant cost and are readily lost by de novo mutations resulting in the rapid evolution of a carbapenem-sensitive phenotype. To explain how carbapenem resistance evolves via multiple, low-fitness single-locus intermediates, we hypothesised that one of these loci had previously conferred adaptation to another antibiotic. Fitness assays in a range of drug concentrations show how selection in the antibiotic ceftazidime can select for one gene (blaDHA-1) potentiating the evolution of carbapenem resistance by a single mutation in a second gene (ompK36). These results show how a patient’s treatment history might shape the evolution of antibiotic resistance and could explain the genetic basis of carbapenem-resistance found in many enteric-pathogens.

Abstract: Transfer entropy (TE) has been used to identify and quantify interactions between physiological systems. Different methods exist to estimate TE, but there is no consensus about which one performs best in specific applications. In this study, five methods (linear, k-nearest neighbors, fixed-binning with ranking, kernel density estimation and adaptive partitioning) were compared. The comparison was made on three simulation models (linear, nonlinear and linear + nonlinear dynamics). From the simulations, it was found that the best method to quantify the different interactions was adaptive partitioning. This method was then applied on data from a polysomnography study, specifically on the ECG and the respiratory signals (nasal airflow and respiratory effort around the thorax). The hypothesis that the linear and nonlinear components of cardio-respiratory interactions during light and deep sleep change with the sleep stage, was tested. Significant differences, after performing surrogate analysis, indicate an increased TE during deep sleep. However, these differences were found to be dependent on the type of respiratory signal and sampling frequency. These results highlight the importance of selecting the appropriate signals, estimation method and surrogate analysis for the study of linear and nonlinear cardio-respiratory interactions. Resumen: La entropía de transferencia (TE) se ha utilizado para identificar y cuantificar las interacciones entre sistemas fisiológicos. Existen diferentes métodos para estimar la TE, pero no hay consenso sobre cuál funciona mejor en aplicaciones específicas. En este estudio, se compararon cinco métodos (lineal, k-nearest neighbors, fixed binning with ranking, kernel density estimation, and adaptive partitioning). La comparación se realizó en tres modelos de simulación (lineal, no lineal y dinámicas lineales + no lineales). A partir de las simulaciones, se encontró que el mejor método para cuantificar las diferentes interacciones fue el adaptive partitioning. Este método se aplicó luego a datos de un estudio de polisomnografía, específicamente a las señales de ECG y respiratorias (flujo nasal y esfuerzo respiratorio alrededor del tórax). Se probó la hipótesis de que los componentes lineales y no lineales de las interacciones cardiorespiratorias durante el sueño ligero y profundo cambian con la etapa del sueño. Diferencias significativas, después de realizar un análisis de subrogados, indican un aumento en la TE durante el sueño profundo. Sin embargo, se encontró que estas diferencias dependían del tipo de señal respiratoria y la frecuencia de muestreo. Estos resultados resaltan la importancia de seleccionar las señales apropiadas, el método de estimación y el análisis de subrogados adecuados para el estudio de las interacciones cardiorespiratorias lineales y no lineales.

Abstract: SEPSIS-3 IN PREGNANT WOMEN IN LABOUR Abstract Introduction: Maternal sepsis represents 10.7% of maternal deaths worldwide, ranking as the third cause of mortality after haemorrhage and hypertensive disorders. Despite its high incidence, it still lacks a gold standard diagnosis. The latest update that proposed new sepsis criteria and scores, Sepsis-3, did not mention pregnancy as part of the study population. This study aims to evaluate the inclusion or exclusion of Sepsis- 3 pregnancy. Methods: This is a literature review of the Sepsis-3 database looking for the inclusion or exclusion of pregnancy from the latest update in sepsis and the basis of current definitions and guidelines. In addition, I reported the retrospective measurement of qSOFA and SOFA scores in 100 pregnant patients in labour from the EPIFEVER-2 cohort at the Royal London Hospital compared to their infection status. Results: Sepsis-3 investigators evaluated the predictive validity of the SOFA and qSOFA score for mortality in sepsis among nearly 1 million patients, however, pregnant women were not included. The SOFA and qSOFA score overlap with the normal physiological changes of pregnancy and labour, in the EPIFEVER-2 cohort 16% of uninfected pregnant patients during labour scored 1 point on qSOFA and 17% 1 point on SOFA score. The highest SOFA score of 3 points was obtained in a patient with bleeding rather than infection. Conclusion: Pregnant patients were not included in the Sepsis-3 databases. Therefore, qSOFA and SOFA score have not been validated for use in this population. Furthermore, as they are not modified for the normal physiological changes of pregnancy, detection of patients without infection has been reported. Further validation of qSOFA or modified SOFA scores as sepsis-specific maternal warning scores is expected in future research.

Abstract: Objective: To evaluate the effect of post-curing method, printing layer thickness, and water storage on the me chanical properties and degree of conversion of a light-curing methacrylate based resin material (IMPRIMO® LC Splint), used for the fabrication of 3D printed occlusal splints and surgical guides. Methods: 96 bar-shaped specimens were 3D printed (Asiga MAX), half of them with a layer thickness of 100 ? m (Group A), and half with 50 ? m (Group B). Each group was divided in three subgroups based on the post-curing method used: post-curing with light emitting diode (LED) and nitrogen gas; post-curing with only LED; and non- post-curing. Half of the specimens from each subgroup were water-stored for 30 days while the other half was dry-stored (n = 8). Flexural strength and flexural modulus were evaluated. Additional specimens were prepared and divided in the same way for surface hardness (n = 96), fracture toughness, and work of fracture (n = 96). Five specimens were selected from each subgroup for evaluating the degree of conversion (DC). Data were collected and statistically analyzed with 1-way, 2-way ANOVA, and Tukey post-hoc analysis (? = 0.05). Results: The 2-way ANOVA showed that the post-curing method and water storage significantly affected the investigated mechanical properties (P < 0.001). The 1-way ANOVA revealed a statistically significant difference among the tested groups on the investigated properties (P < 0.001). After water storage, the 100 ? m subgroup post-cured with only LED showed higher flexural strength (51 ± 9) than the 50 ? m and 100 ? m subgroups that were post-cured with LED in addition to nitrogen gas atmosphere (38 ± 5, 30 ± 3) (p < 0.05). The 50 ? m subgroup post-cured with only LED showed the highest significant flexural modulus values (1.7 ± 0.08) (p < 0.05). However, the 50 ? m subgroup post-cured with LED plus nitrogen showed significantly higher surface hardness values (p < 0.05) among the investigated groups. The non-post-cured subgroups showed the lowest values, which were significantly different from the other subgroups (p < 0.05). Conclusion: The post-curing method, water storage, and printing layer thickness play a role in the mechanical properties of the investigated 3D Printed occlusal splints material. The combination of heat and light within the post-curing unit can enhance the mechanical properties and degree of conversion of 3D printed occlusal splints. Flexural strength and surface hardness can increase when decreasing printing layer thickness. Resumen: Objetivo: Evaluar el efecto del método de poscurado, el espesor de la capa de impresión y el almacenamiento de agua en el tiempo. Propiedades mecánicas y grado de conversión de un material de resina fotopolimerizable a base de metacrilato (IMPRIMO® LC Splint), utilizado para la fabricación de férulas oclusales y guías quirúrgicas impresas en 3D. Métodos: Se imprimieron en 3D (Asiga MAX) 96 muestras en forma de barra, la mitad de ellas con un espesor de capa de 100 ? m. (Grupo A), y la mitad con 50 ? m (Grupo B). Cada grupo se dividió en tres subgrupos según el poscurado. método utilizado: postcurado con diodo emisor de luz (LED) y gas nitrógeno; postcurado solo con LED; y no- después de curado. La mitad de los especímenes de cada subgrupo se almacenaron en agua durante 30 días mientras que la otra mitad se almacenó en agua. almacenado en seco (n = 8). Se evaluaron la resistencia a la flexión y el módulo de flexión. Se prepararon muestras adicionales. y dividido de la misma manera para dureza de la superficie (n = 96), tenacidad a la fractura y trabajo de fractura (n = 96). Se seleccionaron cinco ejemplares de cada subgrupo para evaluar el grado de conversión (DC). Los datos fueron recopilados y analizados estadísticamente con ANOVA de 1 vía, 2 vías y análisis posthoc de Tukey (? = 0,05).

Abstract: The purpose of this in vitro study was to evaluate the mechanical properties of 3 prepolymerized polymethyl methacrylate (PMMA) resins used in the fabrication of computer- aided design and computer-aided manufacturing (CAD-CAM) milled complete dentures (CDs), as well as 2 denture base polymers used for conventionally fabricated CDs. Material and methods. Three CAD-CAM materials were evaluated: Degos Dental L-Temp, IvoBase CAD, and Zirkonzahn Temp Basic Tissue. Two materials used for conventionally manufactured dentures were also included as controls (Palapress and Paladon 65). Each material type was sectioned into bars for flexural strength, nanohardness, elastic modulus, and surface microhardness evaluation (n=8/material). Half of the specimens were stored in water for 30 days, while the other half was dry-stored. A 2-way ANOVA was conducted to detect the effect of material and storage on the evaluated properties (a =.05). Linear contrasts were conducted to compare the differences among the 3 types of CAD-CAM material and the conventional ones. Results. Material type and storage had a significant influence on the flexural strength, nanohardness, elastic modulus, and surface hardness of the materials investigated (P<.001). The post hoc Scheffé test for flexural strength revealed a nonsignificant difference in the interaction between Degos L-Temp and Paladon (P=1.000). In terms of nanohardness, no difference was found when comparing Palapress with Paladon, as well as IvoBase CAD with Zirkonzahn Temp Basic (P=1.000). A nonsignificant interaction in terms of surface hardness was also found between IvoBase CAD and Palapress (P=.575). Resumen: El propósito de este estudio in vitro fue evaluar las propiedades mecánicas de 3 resinas prepolimerizadas de polimetilmetacrilato (PMMA) utilizadas en la fabricación de computadoras Diseño asistido y fabricación asistida por ordenador (CAD-CAM) de prótesis dentales completas fresadas (CD), así como así como 2 polímeros de base para dentaduras postizas utilizados para los CD fabricados de forma convencional. Material y métodos. Se evaluaron tres materiales CAD-CAM: Degos Dental L-Temp, IvoBase CAD y Zirkonzahn Temp Basic Tissue. Dos materiales utilizados de forma convencional. Las dentaduras postizas fabricadas también se incluyeron como controles (Palapress y Paladon 65). Cada El tipo de material se seccionó en barras para determinar la resistencia a la flexión, la nanodureza, el módulo elástico, y evaluación de microdureza superficial (n=8/material). La mitad de los especímenes fueron almacenados en agua durante 30 días, mientras que la otra mitad se almacenó en seco. Se realizó un ANOVA de 2 vías para detectar el efecto del material y el almacenamiento sobre las propiedades evaluadas (a =.05). Lineal Se realizaron contrastes para comparar las diferencias entre los 3 tipos de CAD-CAM. materiales y los convencionales. Resultados. El tipo de material y el almacenamiento tuvieron una influencia significativa en la resistencia a la flexión, nanodureza, módulo elástico y dureza superficial de los materiales investigados (P<0,001). El La prueba post hoc de Scheffé para la resistencia a la flexión reveló una diferencia no significativa en la interacción entre Degos L-Temp y Paladon (P=1.000). En términos de nanodureza, no se encontraron diferencias. Encontrado al comparar Palapress con Paladon, así como IvoBase CAD con Zirkonzahn Temp Básico (P=1.000). También se encontró una interacción no significativa en términos de dureza superficial. entre IvoBase CAD y Palapress (p=0,575).

Abstract: The research aimed to determine the tensile bond strength (TBS) between polymerized intact and ground fiber-reinforced composite (FRC) surfaces. FRC prepregs (a reinforcing fiber pre-impregnated with a semi-interpenetrating polymer network (semi-IPN) resin system; everStick C&B) were divided into two groups: intact FRCs (with a highly PMMA-enriched surface) and ground FRCs (with a low PMMA gradient). Each FRC group was treated with: StickRESIN and G-Multi PRIMER. These groups were further divided into four subgroups based on the application time of the treatment agents: 0.5, 1, 2, and 5 min. Next, a resin luting cement was applied to the FRC substrates on the top of the photo polymerized treating agent. Thereafter, weight loss, surface microhardness, and TBS were evaluated. Three-factor analysis of variance (p ? 0.05) revealed significant differences in the TBS among the FRC groups. The highest TBS was recorded for the intact FRC surface treated with G-Multi PRIMER for 2 min (13.0 ± 1.2 MPa). The monomers and solvents of G-Multi PRIMER showed a time-dependent relationship between treatment time and TBS. They could diffuse into the FRC surface that has a higher PMMA gradient, further resulting in a high TBS between the FRC and resin luting cement. Resumen: La investigación tuvo como objetivo determinar la resistencia a la tracción (TBS) entre polimerizados Superficies compuestas reforzadas con fibra (FRC) intactas y rectificadas. Prepregs de FRC (una fibra de refuerzo preimpregnado con un sistema de resina de red polimérica semiinterpenetrante (semi-IPN); siempreStick C&B) se dividieron en dos grupos: FRC intactos (con una superficie altamente enriquecida en PMMA) y molidos. FRC (con un gradiente bajo de PMMA). Cada grupo de FRC fue tratado con: StickRESIN y G-Multi CEBADOR. Estos grupos se dividieron en cuatro subgrupos según el tiempo de aplicación del agentes de tratamiento: 0,5, 1, 2 y 5 min. A continuación, se aplicó un cemento de resina a los sustratos de FRC. en la parte superior del agente de tratamiento fotopolimerizado. Posteriormente, pérdida de peso, microdureza superficial, y TBS fueron evaluados. El análisis de varianza de tres factores (p ? 0,05) reveló diferencias significativas en el TBS entre los grupos del FRC. El TBS más alto se registró para la superficie intacta de FRC tratada con G-Multi PRIMER durante 2 min (13,0 ± 1,2 MPa). Los monómeros y disolventes de G-Multi PRIMER mostró una relación dependiente del tiempo entre el tiempo de tratamiento y TBS. Podrían difundirse hacia el Superficie de FRC que tiene un gradiente de PMMA más alto, lo que resulta además en un TBS alto entre el FRC y Cemento de fijación de resina.

Abstract: Statement of problem: The fracture incidence of implant-supported overdentures is more frequent in the area of attachment because of stress concentration and denture deformation in this area. How Eglass fiber reinforcement can address this problem is unclear. Purpose: The purpose of this in vitro study was to evaluate the influence of unidirectional E-glass fiber reinforcement on the mid-line denture base strains of single implant-supported overdentures. Material and methods. An experimental acrylic resin cast was constructed with a single implant placed in the mid-line area and a ball attachment screwed to the implant. Twenty-four experimental overdentures were constructed and divided into 4 groups: group AP fabricated from autopolymerizing acrylic resin without fiber reinforcement, group APF fabricated from autopolymerizing acrylic resin with unidirectional E-glass fiber reinforcement running over the residual ridge and the ball matrix, group HP fabricated from heatpolymerized acrylic resin without fiber reinforcement, and group HPF fabricated from heat-polymerized acrylic resin with unidirectional E-glass fiber reinforcement running over the residual ridge and the ball matrix. A biaxial rosette strain gauge was attached to the incisor areas of each overdenture above the attachment level (Ch1, Ch2) and to a multichannel digital strain meter. A static vertical load of 100 N was applied to the first molar area bilaterally by using a universal testing device during strain measurement procedures. The differences in the mean strain and deflection values among the investigated groups were evaluated for statistical significance using 1-way analysis of variance (ANOVA) with the Tukey post hoc multiple comparison (a =.05). Results. The type of acrylic resin did not have a statistically significant effect on the mean strain values among groups (P=.350), while the reinforcement did significantly affect them (P<.001). The interaction between reinforcement and acrylic resin was not statistically significant (P=.552). Both strain gauge channels in group APF and group HPF recorded significantly lower strain values by almost 50% than those of group AP and group HP (P<.05). Conclusions. Unidirectional E-glass fiber reinforcement placed over the residual ridge and implant attachment significantly reduced denture base strains and deformation of single implantsupported overdentures. Resumen: Declaración del problema. La incidencia de fracturas de las sobredentaduras implantosoportadas es más frecuente en el área de inserción debido a la concentración de tensiones y la deformación de la dentadura postiza en esta área. No está claro cómo el refuerzo de fibra de vidrio E puede abordar este problema. Objetivo. El propósito de este estudio in vitro fue evaluar la influencia de unidireccional Refuerzo de fibra de vidrio E en la línea media de la base de la dentadura postiza de un solo implante. Material y métodos. Se construyó un modelo experimental de resina acrílica con un solo implante. colocado en la zona de la línea media y un accesorio de bola atornillado al implante. Veinticuatro se construyeron sobredentaduras experimentales y se dividieron en 4 grupos: grupo AP fabricado de resina acrílica autopolimerizable sin refuerzo de fibra, grupo APF fabricado con resina acrílica autopolimerizable con refuerzo de fibra de vidrio E unidireccional que recorre el cresta residual y matriz de bolas, grupo HP fabricados con resina acrílica termopolimerizada sin refuerzo de fibra, y grupo HPF fabricado a partir de resina acrílica termopolimerizada con Refuerzo unidireccional de fibra de vidrio E que recorre la cresta residual y la matriz de bolas. Se adjuntó un medidor de tensión de roseta biaxial a las áreas de los incisivos de cada sobredentadura por encima del nivel de conexión (Ch1, Ch2) y a un medidor de tensión digital multicanal.

Abstract: The aim of this in vitro study was to assess the mechanical properties of five commercially available subtractive computer-aided design and computer-aided manufacturing (CAD-CAM) milled splint materials, as well as to compare them with conventional heat-polymerized and autopolymerizing resins used in the con struction of conventional splints. Material and methods: Five CAD-CAM milled (ProArt CAD Splint, Therapon Transpa, Temp Premium Flexible Transpa, Cast, and Aqua), one autopolymerizing (Palapress), and one heat-polymerized (Paladon 65) resin materials were evaluated. Flexural strength, E-modulus, Vickers hardness, fracture toughness, fracture work, water sorption, and water solubility were measured. Samples were evaluated after dry and water storage for 30 days at 37 ? C. Data were collected and statistically analyzed. Results: Under both storage circumstances, the flexural strength values of Paladon 65, Therapon Transpa, Temp Premium Flexible Transpa, and Aqua were statistically non-significant (P=0.055). The polycarbonate-based CAD-CAM material Temp Premium Flexible Transpa had the highest statistically significant values of the frac ture toughness and fracture work (P<0.001). Moreover, it exhibited the lowest percentages of water sorption and water solubility among the investigated materials (P<0.001). All of the CAD-CAM materials exhibited dry elastic moduli greater than Palapress and lower than Paladon 65. One of the CAD-CAM materials, Cast, had the highest dry Vickers hardness value, which was nonsignificant when compared to Therapon Transpa (P=0.762). Conclusion: CAD-CAM polycarbonate-based splint materials exhibit higher fracture toughness and fracture work as well as lower water sorption and solubility than polymethyl methacrylate-based ones. The mechanical characteristics of the assessed CAD-CAM milled splint materials were not typically superior to those of the conventional heat-polymerized resin. However, some of them outperformed the autopolymerizing acrylic resin in terms of flexural strength, surface microhardness, water sorption, and water solubility. Resumen: El objetivo de este estudio in vitro fue evaluar las propiedades mecánicas de cinco disponibles comercialmente materiales de férula fresados de diseño sustractivo asistido por computadora y fabricación asistida por computadora (CAD-CAM), como así como compararlos con resinas convencionales polimerizadas por calor y autopolimerizantes utilizadas en la industria. Construcción de férulas convencionales. Material y métodos: Cinco fresados CAD-CAM (ProArt CAD Splint, Therapon Transpa, Temp Premium Flexible Transpa, Cast y Aqua), una resina autopolimerizable (Palapress) y una resina termopolimerizada (Paladon 65). Se evaluaron los materiales. Resistencia a la flexión, módulo E, dureza Vickers, tenacidad a la fractura, trabajo de fractura, Se midieron la sorción de agua y la solubilidad en agua. Las muestras se evaluaron después del almacenamiento seco y en agua durante 30 días a 37 ? C. Los datos fueron recolectados y analizados estadísticamente. Resultados: En ambas circunstancias de almacenamiento, los valores de resistencia a la flexión de Paladon 65, Therapon Transpa, Temp Premium Flexible Transpa y Aqua no fueron estadísticamente significativos (P = 0,055). La base de policarbonato El material CAD-CAM Temp Premium Flexible Transpa tuvo los valores estadísticamente significativos más altos de fractura tenacidad de la estructura y trabajo de fractura (P <0,001). Además, exhibió los porcentajes más bajos de sorción de agua y solubilidad en agua entre los materiales investigados (P<0,001). Todos los materiales CAD-CAM mostraron elasticidad seca. módulos mayores que Palapress e inferiores que Paladon 65. Uno de los materiales CAD-CAM, Cast, tuvo el mayor valor de dureza Vickers seco, que no fue significativo en comparación con Therapon Transpa (P = 0,762).

Abstract: The aim of this work was to investigate the effect of two post-curing methods on the mechanical properties of a 3D-printed denture base material. Additionally, to compare the mechanical properties of that 3D-printed material with those of conventional autopolymerizing and a heat-cured denture base material. A resin for 3D-printing denture base (Imprimo ®), a heat-polymerizing acrylic resin (Paladon ® 65), and an autopolymerizing acrylic resin (Palapress ®) were investigated. Flexural strength, elastic modulus, fracture toughness, work of fracture, water sorption, and water solubility were evaluated. The 3D-printed test specimens were post-cured using two different units (Imprimo Cure ® and Form Cure ®). The tests were carried out after both dry and 30 days water storage. Data were collected and statistically analyzed. Resin type had a significant effect on the flexural strength, elastic modulus, fracture toughness, and work of fracture (p < 0.001). The flexural strength and elastic modulus for the heat-cured polymer were significantly the highest among all investigated groups regardless of the storage condition (p < 0.001). The fracture toughness and work of fracture of the 3Dprinted material were significantly the lowest (p < 0.001). The heat-cured polymer had the lowest significant water solubility (p < 0.001). The post-curing method had an impact on the flexural strength of the investigated 3D-printed denture base material. The flexural strength, elastic modulus, fracture toughness, work of fracture of the 3D-printed material were inferior to those of the heat-cured one. Increased post-curing temperature may enhance the flexural properties of resin monomers used for 3D-printing dental appliances. Resumen: El objetivo de este trabajo fue investigar el efecto de dos métodos de poscurado en la Propiedades mecánicas de un material base para prótesis dental impreso en 3D. Además, para comparar la mecánica propiedades de ese material impreso en 3D con las de la autopolimerización convencional y un curado por calor material base de la dentadura postiza. Una resina para la impresión 3D de bases de prótesis dentales (Imprimo ®), un acrílico termopolimerizable Se investigaron una resina (Paladon ® 65) y una resina acrílica autopolimerizable (Palapress ®). Flexión Resistencia, módulo elástico, tenacidad a la fractura, trabajo de fractura, sorción de agua y solubilidad en agua. fueron evaluados. Las muestras de prueba impresas en 3D se curaron posteriormente utilizando dos unidades diferentes (Imprimo Cure® y Form Cure®). Las pruebas se llevaron a cabo después de un almacenamiento en seco y durante 30 días en agua. Datos fueron recolectados y analizados estadísticamente. El tipo de resina tuvo un efecto significativo sobre la resistencia a la flexión, módulo elástico, tenacidad a la fractura y trabajo de fractura (p < 0,001). La resistencia a la flexión y El módulo elástico para el polímero curado con calor fue significativamente el más alto entre todos los investigados. grupos independientemente de la condición de almacenamiento (p < 0,001). La tenacidad a la fractura y el trabajo de fractura. del material impreso en 3D fueron significativamente los más bajos (p <0,001). El polímero curado por calor tenía la solubilidad en agua significativa más baja (p < 0,001). El método de poscurado tuvo un impacto en la Resistencia a la flexión del material de base de la dentadura postiza impreso en 3D investigado. La resistencia a la flexión, elástica. El módulo, la tenacidad a la fractura y el trabajo de fractura del material impreso en 3D fueron inferiores a los del curado con calor. El aumento de la temperatura de poscurado puede mejorar las propiedades de flexión de la resina monómeros utilizados para aparatos dentales de impresión 3D.

Abstract: Aim: the aim of this study was to compare the flexural strength and elastic modulus of three-dimensionally (3D) printed, conventional heat-cured, and high-impact implant-supported overdenture materials specimens. Materials and Methods: Thirty implant-supported overdenture materials specimens (bar-shaped, 65.0 × 10.2 × 5.1 ± 0.2 mm 3) with one central hole were fabricated using 3D-printed, heat-cured conventional, and high-impact denture base resins (n = 10/group). Autopolymerizing acrylic resin was used to attach titanium matrix housings to the central holes of the specimens. A three-point bending test was conducted using a universal testing machine and a model analog with a crosshead speed of 5 mm/min. The indicative flexural strength and elastic modulus were recorded. Data were statistically analyzed using analysis of variance (ANOVA) and the Tukey tests at ? = 0.05. Results: One-way ANOVA revealed a significant effect of denture base material on the flexural strength (p < 0.001) but not on the elastic modulus (p = 0.451) of the evaluated materials. The flexural strength of the 3D-printed specimens (95.99 ± 9.87 MPa) was significantly higher than the conventional (77.18 ± 9.69 MPa; p < 0.001) and high-impact ones (82.74 ± 7.73 MPa; p = 0.002). Conclusions: The maximum flexural strength was observed in the 3D-printed implant- supported overdenture material specimens, which might indicate their suitability as an alternative to the conventionally fabricated ones. Flexural strength and elastic modulus of conventional and high-impact heat-cured implant-supported overdenture materials specimens were comparable. Resumen: Objetivo: el objetivo de este estudio fue comparar la resistencia a la flexión y el módulo elástico de impresos en tres dimensiones (3D), curados con calor convencionales y soportados por implantes de alto impacto Muestras de materiales para sobredentaduras. Materiales y métodos: Treinta sobredentaduras implantosoportadas. Se fabricaron muestras de materiales (en forma de barra, 65,0 × 10,2 × 5,1 ± 0,2 mm 3) con un orificio central. utilizando resinas de base para prótesis dentales impresas en 3D, termocuradas convencionales y de alto impacto (n = 10/grupo). Se utilizó resina acrílica autopolimerizante para unir carcasas de matriz de titanio a los orificios centrales de los ejemplares. Se realizó una prueba de flexión de tres puntos utilizando una máquina de prueba universal y un modelo analógico con una velocidad de cruceta de 5 mm/min. La resistencia a la flexión y el elástico indicativos. Se registraron los módulos. Los datos se analizaron estadísticamente mediante análisis de varianza (ANOVA) y las pruebas de Tukey en ? = 0,05. Resultados: ANOVA unidireccional reveló un efecto significativo de la base de la dentadura postiza material en la resistencia a la flexión (p < 0,001) pero no en el módulo elástico (p = 0,451) del evaluando materiales. La resistencia a la flexión de las muestras impresas en 3D (95,99 ± 9,87 MPa) fue significativamente superiores a los convencionales (77,18 ± 9,69 MPa; p < 0,001) y a los de alto impacto (82,74 ± 7,73 MPa; p = 0,002). Conclusiones: La máxima resistencia a la flexión se observó en el implante impreso en 3D. Muestras de material para sobredentaduras soportadas, que podrían indicar su idoneidad como alternativa. A los fabricados convencionalmente. Resistencia a la flexión y módulo elástico de convencionales y Las muestras de materiales para sobredentaduras implantosoportados termoendurecidos de alto impacto fueron comparables.