Determination of the California Bearing Ratio of the Subgrade and Granular Base Using Artificial Neural Networks

The objective of the research is to estimate the value of the California bearing ratio (CBR) through the application of ANN. The methodology consists of creating a database with soil index and CBR variables of the subgrades and granular base of pavements in Jaen, Peru, carried out in the soil mechanics laboratories of the city and the National University of Jaen. In addition, the Python library Seaborn is for variable selection and relevance, and the scikit-learn and Keras libraries were used for the learning, training, and validation stage. Five ANN are proposed to estimate the CBR value, obtaining an error of 4.47% in the validation stage. It can be concluded that this method is effective and valid to determine the CBR value in subgrades and granular bases of any pavement for its evaluation or design

Evaluación de la absorción de agua y solubilidad de adhesivos dentales simplificados: universales vs. de grabado total

El objetivo del presente trabajo fue evaluar la absorción de agua y solubilidad de seis adhesivos dentales simplificados. Fueron utilizados tres adhesivos de grabado total de 2 pasos (Single Bond 2 [SE3], Tetric N-Bond [TB] y Ambar [AM]), y tres adhesivos universales (Single Bond Universal [SU], Tetric N-Bond Universal [TU] y Ambar Universal [AU]). Para la obtención de los valores de absorción y solubilidad tras 7 días de inmersión en agua se utilizó la especificación ISO 4049:2009 con modificaciones en lo que respecta a las dimensiones de los especímenes en forma de disco (6 mm de diámetro y 1 mm de grosor, n = 8). Los valores de absorción de agua y solubilidad fueron analizados independientemente usando análisis de varianza de un factor y la prueba estadística de Tukey en nivel de significancia de 5%. La absorción de agua de los adhesivos de grabado total de 2 pasos resultó ser estadísticamente mayor que la de los adhesivos universales, excepto para Ambar (SB > TB > SU > TU > AU = AM). Los adhesivos de grabado total de 2 pasos presentaron estadísticamente menor solubilidad que los adhesivos universales, a excepción del Single Bond 2 (SU = TU SB = AU > TB = AM). Las imágenes de los especímenes obtenidas en el estereomicroscopio mostraron mayores señales de degradación en los adhesivos universales. Se concluye que los adhesivos universales son más susceptibles a la degradación en medio acuoso que los de grabado total de 2 pasos.Universidad Privada Juan Pablo IITrabajo de investigació

Convolutional Neural Network for Predicting Failure Type in Concrete Cylinders During Compression Testing

Cracks in concrete cause structural damage, and it is important to identify and classify them. The objective of the research was to describe the behavior and predict the type of failure in concrete cylinders using convolutional neural networks. The methodology consisted of creating a database of 2650 images of failure types in concrete cylinders tested in compression at the Laboratory of Testing and Strength of Materials of the National University of Jaen, Cajamarca, Peru. To identify cracks on the concrete surface, the database was divided into training (60%), validation (20%), and testing (20%), and a transfer learning approach was developed using the MobileNet, DenseNet121, ResNet50, and VGG16 algorithms from the Keras library, programmed in Python. To validate the performance of each model, the following indicators were used: recall, precision, and F1 score. The results show that the models studied correctly classified the type of failure in concrete with accuracies of 96, 91, 86, and 90%, with the MobileNet algorithm being the best predictor with 96%. The novelty of the study was the development of deep learning algorithms with different architectures that can be used in structural health assessment as an automated and reliable method compared to traditional ones. In addition, these trained algorithms can be used as source code in drones for structural monitoring. Doi: 10.28991/CEJ-2023-09-09-01 Full Text: PD

Marginal adaptation of lithium disilicate crowns obtained by scanning techniques (CAD/CAM): in vitro confocal microscopy analysis

Objetivo. El objetivo de este estudio fue evaluar la adaptación marginal de coronas de disilicato de litio obtenidas mediante técnicas de escaneo (CAD/CAM), antes y después de la cristalización, a través de análisis in vitro con microscopía confocal (MC). Métodos. Fueron confeccionadas 16 réplicas en poliuretano a partir de la pieza 1.4, de modelo typodont, tallada para corona total. Las réplicas fueron divididas en dos grupos, de acuerdo a la técnica de escaneo: Técnica Indirecta (Grupo IND, n=08), donde modelos de yeso fueron escaneados con escáner de laboratorio (inEos X5, Sirona Dental Systems) y Técnica Directa (Grupo DIR, n=08), donde modelos typodont fueron escaneados con escáner intraoral (CEREC BlueCam, Sirona Dental Systems). A seguir, se fresaron (inLab MC XL, Sirona Dental Systems) coronas en disilicato de litio (IPS e.max CAD, Ivoclar Vivadent) y se adaptaron a las réplicas. Se evaluó la adaptación marginal con análisis de MC en dos momentos, antes y después de la cristalización del disilicato de litio. Los datos fueron analizados con la prueba de Mann-Whitney, t de Student y Wilcoxon (α= 0,05). Resultados. Hubo una diferencia estadísticamente significativa en la adaptación marginal horizontal entre los grupos IND y DIR después de la cristalización (p=0,05). En el grupo IND, la comparación de la adaptación marginal vertical antes y después de la cristalización mostró una diferencia estadísticamente significativa (p=0,038). Conclusiones. Las coronas de disilicato de litio obtenidas mediante escaneo directo (CAD/CAM) presentaron menor desajuste marginal vertical. La etapa de cristalización afectó la adaptación marginal de las coronas.Objective. This study aimed to evaluate lithium disilicate marginal adaption on crowns by scanning techniques (CAD/CAM), before and after crystallization, through confocal microscopy (CM) in vitro analysis. Methods. Sixteen polyurethane replicas were performed from tooth 1.4, of a typodont model, prepared for a full crown. The replicas were divided into two groups, according to the scanning technique: Indirect Technique (Group IND, n=08), where dental stone models were scanned with a laboratory scanner (inEos X5, Sirona Dental Systems) and Direct Technique (Group DIR, n=08), where typodont models were scanned with an intraoral scanner (CEREC BlueCam, Sirona Dental Systems). Then, the lithium disilicate crowns (IPS e.max CAD, Ivoclar Vivadent) were milled (inLab MC XL, Sirona Dental Systems) and adapted to the replicas. Marginal adaptation was evaluated with CM analysis before and after lithium disilicate crystallization. Data were analyzed with the Mann-Whitney, t test, and Wilconxon test (α=0.05). Results. There was a statistically significant difference in horizontal marginal adaptation between IND and DIR groups after crystallization (p=0.05). In IND group, the comparison of vertical marginal adaptation before and after crystallization showed a statistically significant difference (p=0.038). Conclusions. Lithium disilicate crowns obtained by direct scanning technique (CAD/CAD) showed less vertical marginal maladjustment. The crystallization stage affected the crown’s marginal adaptation

Influence of pH, bleaching agents, and acid etching on surface wear of bovine enamel

ABSTRACT Development of new materials for tooth bleaching justifies the need for studies to evaluate the changes in the enamel surface caused by different bleaching protocols. Objective The aim of this study was to evaluate the bovine dental enamel wear in function of different bleaching gel protocols, acid etching and pH variation. Material and Methods Sixty fragments of bovine teeth were cut, obtaining a control and test areas. In the test area, one half received etching followed by a bleaching gel application, and the other half, only the bleaching gel. The fragments were randomly divided into six groups (n=10), each one received one bleaching session with five hydrogen peroxide gel applications of 8 min, activated with hybrid light, diode laser/blue LED (HL) or diode laser/violet LED (VHL) (experimental): Control (C); 35% Total Blanc Office (TBO35HL); 35% Lase Peroxide Sensy (LPS35HL); 25% Lase Peroxide Sensy II (LPS25HL); 15% Lase Peroxide Lite (LPL15HL); and 10% hydrogen peroxide (experimental) (EXP10VHL). pH values were determined by a pHmeter at the initial and final time periods. Specimens were stored, subjected to simulated brushing cycles, and the superficial wear was determined (μm). ANOVA and Tukey´s tests were applied (α=0.05). Results The pH showed a slight decrease, except for Group LPL15HL. Group LPS25HL showed the highest degree of wear, with and without etching. Conclusion There was a decrease from the initial to the final pH. Different bleaching gels were able to increase the surface wear values after simulated brushing. Acid etching before bleaching increased surface wear values in all groups

Double-blind, randomized clinical trial of Biosilicate under resin composite restorations in caries affected teeth

O presente estudo teve por objetivo avaliar o efeito de um biomaterial vitrocerâmico (Biosilicato®) no desempenho clínico de restaurações posteriores em resina composta. 92 cavidades Classe I e Classe II com lesão de cárie (no terço meio da dentina) foram selecionadas e distribuídas aleatoriamente em quatro grupos segundo o protocolo adesivo: 1- Biosilicato / sistema adesivo convencional de dois passos, 2- Controle / sistema adesivo convencional de dois passos, 3- Biosilicato / sistema adesivo autocondicionante de dois passos e 4- Controle / sistema adesivo autocondicionante de dois passos. Dois operadores realizaram os protocolos adesivos e restauraram as cavidades com uma resina composta nanohíbrida (IPS Empress, Ivoclar) usando a técnica incremental. Os participantes foram remarcados após uma semana, 6, 12 e 18 meses para avaliação clínica realizada por dois examinadores, cegados e calibrados de acordo com os critérios FDI. Os dados foram analisados com o teste não paramétrico de Kruskal-Wallis e o teste de Dunn de comparação múltipla, com nível de significância de 5%. Os resultados revelaram que não houve diferença estatisticamente significante (p > 0.05) entre os grupos experimentais e os respectivos controles em nenhuma avaliação, entretanto, houve diferença estatisticamente significativa (p 0.05) between the experimental groups and their respective controls; however, there were statistical difference between control groups (2 x 4) (p < 0.05) for anatomical form (1 week) and marginal adaptation (18 months). Group 2 was statistically different from Group 3 (p < 0.05), for fracture of material/retention (18 months) and marginal adaptation category (1 week), where Group 2 showed the better performance. The use of Biosilicate, in a restorative protocol for caries-affected dentin, did not alter the clinical performance of posterior resin composite restorations. The association between Biosilicate and two-step self-etching adhesive system showed an inferior clinical performance, compared to the conventional adhesive system (control), in terms of marginal adaptation and fracture of material/retention

Evaluating remineralizing and desensitizing agents in dental bleaching treatment: in vitro study

O objetivo deste estudo foi avaliar comparativamente, in vitro, o efeito de agentes remineralizadores e dessensibilizantes na rugosidade superficial e microdureza do esmalte e dentina bovina exposta a peróxido de carbamida a 16% (T1) ou peróxido de hidrogênio a 35% (T2). Os agentes clareadores T1 e T2 conjuntamente com os agentes remineralizadores/ dessensibilizantes - dentifrício Sensodyne® (D1); dentifrício experimental com 7,5% de micro-partículas de Biosilicato® (D2); dentifrício Odontis RX® (D3); dentifrício Sorriso® (D4); pasta experimental com micropartículas de Biosilicato® (D5); Desensebilize Nano P® (D6); pasta experimental com micropartículas de Bioglass® tipo 45S5 (D7); água destilada (GC) - foram usados considerando os grupos experimentais: T1/D1; T1/D2; T1/D3; T1/D4; T1/D5; T1/D6; T1/D7; T1/GC e T2/D1; T2/D2; T2/D3; T2/D4; T2/D5; T2/D6; T2/D7; T2/GC. Análise de rugosidade superficial (Ra), microdureza e imagens em microscopia eletrônica de varredura (MEV) foram realizadas antes (t0) e após (t1) o tratamento com os géis clareadores (T1= 14 dias/ 4h por dia; T2= sessão única) e os produtos remineralizadores/dessensibilizantes. Os dados colhidos foram analisados intra e intergrupos, estatisticamente por meio de Análise de Variância e Teste de Tukey. Os resultados mostraram que na rugosidade superficial não houve diferença significante (p>0.05) entre a rugosidade inicial (t0) e final (t1) tanto no esmalte quanto na dentina. A microdureza diminuiu nas amostras de dentina para o grupo T1/D6 (t0=40,99/ t1=29,11) e foi aumentada nas amostras de esmalte do grupo T1/D1 (t0=255,0/ t1=318,1). Conclui-se que o tratamento com peróxido de carbamida a 16% ou peróxido de hidrogênio a 35% associado aos agentes dessensibilizante/remineralizantes avaliados neste estudo não alteraram a rugosidade superficial do esmalte e dentina bovina, no entanto a microdureza pode ser alterada quando o peróxido de carbamida a 16% é usado.This study aimed to evaluate in vitro the effect of remineralizing and desensitizing agents on microhardness (MH) and roughness (RG) enamel and dentin bovine samples exposed to 16% carbamide peroxide (T1) or 35% hydrogen peroxide (T2). Dental bleaching agents - T1 and T2 - together with desensitizing/ remineralizing agents - Sensodyne® dentifrice (D1); experimental dentifrice containing 7,5% micron-sized particles of Biosilicate® (D2); Odontis RX® dentifrice (D3); Sorriso® dentifrice (D4); microsized particles of Biosilicate® paste (D5); Dessensebilize Nano P® (D6); Bioglass® type 45S5 paste (D7); distilled water (CG) were used according to the experimental groups: T1/D1; T1/D2; T1/D3; T1/D4; T1/D5; T1/D6; T1/D7; T1/GC and T2/D1; T2/D2; T2/D3; T2/D4; T2/D5; T2/D6; T2/D7; T2/CG. MH, RG measurements, and images using scanning electron microscopy (SEM) were made on the samples before (t0) and after (t1) the treatment with the bleaching gels (T1= 14 days/ 04 hours/day; T2=single session) and the desensitizing/remineralizing agents. Data was analyzed statistically with One way-ANOVA and posterior Tukey Test. RG evaluation revealed no significant difference (p>0.05) between baseline (t0) and final (t1) RG for all experimental groups. MH decreased in dentine samples for T1/D6 (t0=40,99/ t1=29,11) and increased in enamel samples for T1/D1 (t0=255,0/ t1=318,1). It was concluded that the treatment with carbamide peroxide at 16% or hydrogen peroxide at 35% in combination with desensitizing/ remineralizing agents didnt alter enamel and dentin surface roughness; however microhardness could be affected when peroxide carbamide at 16 % is used

Double-blind, randomized clinical trial of Biosilicate under resin composite restorations in caries affected teeth

O presente estudo teve por objetivo avaliar o efeito de um biomaterial vitrocerâmico (Biosilicato®) no desempenho clínico de restaurações posteriores em resina composta. 92 cavidades Classe I e Classe II com lesão de cárie (no terço meio da dentina) foram selecionadas e distribuídas aleatoriamente em quatro grupos segundo o protocolo adesivo: 1- Biosilicato / sistema adesivo convencional de dois passos, 2- Controle / sistema adesivo convencional de dois passos, 3- Biosilicato / sistema adesivo autocondicionante de dois passos e 4- Controle / sistema adesivo autocondicionante de dois passos. Dois operadores realizaram os protocolos adesivos e restauraram as cavidades com uma resina composta nanohíbrida (IPS Empress, Ivoclar) usando a técnica incremental. Os participantes foram remarcados após uma semana, 6, 12 e 18 meses para avaliação clínica realizada por dois examinadores, cegados e calibrados de acordo com os critérios FDI. Os dados foram analisados com o teste não paramétrico de Kruskal-Wallis e o teste de Dunn de comparação múltipla, com nível de significância de 5%. Os resultados revelaram que não houve diferença estatisticamente significante (p > 0.05) entre os grupos experimentais e os respectivos controles em nenhuma avaliação, entretanto, houve diferença estatisticamente significativa (p 0.05) between the experimental groups and their respective controls; however, there were statistical difference between control groups (2 x 4) (p < 0.05) for anatomical form (1 week) and marginal adaptation (18 months). Group 2 was statistically different from Group 3 (p < 0.05), for fracture of material/retention (18 months) and marginal adaptation category (1 week), where Group 2 showed the better performance. The use of Biosilicate, in a restorative protocol for caries-affected dentin, did not alter the clinical performance of posterior resin composite restorations. The association between Biosilicate and two-step self-etching adhesive system showed an inferior clinical performance, compared to the conventional adhesive system (control), in terms of marginal adaptation and fracture of material/retention

Vehicle quotation system with integration to ERP Dynamics 365 for the commercial network of dealers

El objetivo de este estudio es diseñar una solución y construir un sistema de cotizaciones de vehículos para disminuir en 70% el tiempo del registro en la captación de clientes a través de una página Web dispuesta a la red de concesionarios que se integra con ERP Dynamic 365 de la empresa, que es la importadora y comercializadora oficial de la marca de vehículos Hyundai. La metodología que se aplica como buenas prácticas se presenta en el desarrollo del proyecto describiendo su diseño, desarrollo orientado a funcionalidades y validación. Con el resultado de la validación se comprueba el cumplimiento de los 10 principios heurísticos de Nielsen (usabilidad y cumplimiento de buenas prácticas de diseño). Asimismo, validando la confiabilidad utilizando el coeficiente alfa de Cronbach en el cual se obtuvo un valor de 0.875 que indica una fuerte coherencia interna con relación a las preguntas formuladas a los expertos y de las cuales 3 principios se cumplen al 100% teniendo como resultado que el sistema cumple con los requisitos para generar una cotización (Visibilidad del estado del sistema), la interfaz para el usuario es fácil de usar por ser muy intuitiva (Consistencia y estándares) y que el sistema es compatible con diferentes navegadores y dispositivos (Diseño estético y minimalista). Finalmente, se llega a la conclusión, en el logro satisfactorio del sistema como solución, demostrando optimización en el tiempo del proceso de cotizaciones con un valor de reducción del 80%.The objective of this study is to design a solution and build a vehicle quotation system to reduce by 70% the registration time in customer acquisition through a Web page available to the dealer network that integrates with ERP Dynamic 365 of the company, which is the official importer and marketer of the Hyundai vehicle brand. The methodology applied as good practices is presented in the development of the project describing its design, development oriented to functionalities and validation. With the result of the validation, compliance with Nielsen's 10 heuristic principles (usability and compliance with good design practices) is checked. Also, validating the reliability using Cronbach's alpha coefficient in which a value of 0.875 was obtained, indicating a strong internal consistency in relation to the questions asked to the experts and of which 3 principles are met at 100% having as a result that the system meets the requirements to generate a quote (Visibility of the system status), the user interface is easy to use for being very intuitive (Consistency and standards) and that the system is compatible with different browsers and devices (Aesthetic and minimalist design). Finally, it is concluded, in the satisfactory achievement of the system as a solution, demonstrating optimization in the time of the quotation process with a reduction value of 80%.Trabajo de Suficiencia Profesiona