Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

El propósito general de esta investigación fue mostrar cómo la adición de confitillo en proporciones de 1, 2, 3, 4 y 5%, influye en la mezcla asfáltica en caliente y el diseño de pavimento flexible para las calles de una ciudad en Perú. El estudio se orientó en la metodología aplicada, enfoque cuantitativo, diseño experimental y nivel explicativo. Se realizó un muestreo, donde se utilizó 33 briquetas para la población y 18 de ellas para la muestra. La investigación evidenció que el diseño patrón se obtuvo con un cemento asfáltico CA al 5.75%, obteniéndose una estabilidad de 1204 kg, un flujo de 3.41 mm, un porcentaje de vacíos del 4.15% y un índice de rigidez de 3534 kg/cm. Al agregar confitillo en 5% en la mezcla asfáltica en caliente MAC en lugar de agregado fino, la estabilidad, el flujo, el porcentaje de vacíos y el índice de rigidez aumentaron en comparación al diseño patrón, alcanzando valores de 1498 kg, 3.81 mm, 5.01% y 3951 kg/cm, respectivamente. Así mismo se demostró que, la adición de confitillo en la MAC, influye en el espesor de la capa asfáltica reduciendo sus dimensiones y por ende en el costo por m3 de la mezcla asfáltica. Evidencias, que conllevaron a concluir que, la adición de confitillo tiene influencia en la mezcla asfáltica en caliente y el diseño del pavimento flexible.

In recent years, post-failure analysis has gained prominence in the geotechnical and mining industries for risk assessment and mitigation. Estimating runout from tailings dam failures is now a regulatory requirement for the design, operation, and closure oftailings storage facilities (TSFs). The key challenge lies in modelling large deformations while accounting for continuum soil mechanics. The Material Point Method (MPM), a continuum mechanics approach, shows promise due to its efficiency in modellinglarge deformations. It is particularly valuable for studying the entire instability process, including static stability, failure initiation, post-failure behaviour, and subsequent runout. This study applies MPM to a real case: the collapse of the Las Palmas tailings dam,triggered by the 2010 Maule earthquake in Chile (Mw 8.8). The dam is located approximately 30 km northwest of Talca, in Chile’s Maule region. The computational model considers a two-dimensional plane-strain condition with fully saturated porous media and a coupled hydro-mechanical formulation. The results include velocity, deformation, displacement, and final deposition patterns. Notably, the computed runout distance aligns well with post-collapse field observations, validating the method’s capability toreplicate real cases. This research enhances our understanding of failure mechanisms and contributes to improved risk management in the mining industry.

El crecimiento demográfico impulsa la producción agroindustrial, generando una gran cantidad de residuos orgánicos que comprometen los ecosistemas. Entre estos residuos, la semilla de papaya surge como un recurso muy interesante para fabricar paneles aglomerados, ofreciendo una alternativa a los paneles de madera y reduciendo la explotación de recursos forestales. Esteestudio evalúa algunas propiedades físicas y mecánicas de muestras prismáticas de semillas de papaya combinadas con agua y un adhesivo comercial, además de fabricar y probar un prototipo de panel estructural aislado (SIP). Los resultados indican que, a pesar de su alta absorción e hinchamiento, las muestras con 55% de adhesivo y pre-humectadas mostraron mayor resistencia a la flexión y compresión. Así, los paneles de semillas de papaya podrían reutilizar este residuo de manera sostenible, reduciendo el impacto ambiental y valorizando un residuo agroindustrial.

The trend in the dynamic analysis of tailings deposits is to use advanced constitutive models in order to properly capture the cyclic behavior of the materials and thus have a better estimation of the physical stability of these structures. In this context, the main objective of this research is to compare the results of numerical simulations performed with a constitutive model used in current practice, such as the Mohr-Coulomb elastoplastic model, and an advanced constitutive model based on the critical state theory. This model, P2PSand, has the ability to represent the contractive and dilatant behavior of soils and the essential characteristics of the cyclic behavior of sands. From the results of the numerical analysis, the following conclusions can be drawn: P2PSand is able to adequately simulate the dynamic behavior of the sand in the tailing dam subjected to a measured earthquake of medium intensity (Mw = 5.4). P2PSand and Mohr-Coulomb constitutive models have the capability to analyze a maximum credible earthquake of magnitude 8.0 (Mw = 8.0), even if the earthquake is increased by 1.5 and 2 and if an advanced constitutive model is not used, the use of an elastic-plastic model with the addition of hysteretic damping is recommended.

Designing shallow foundations on fractured rock is a complex challenge for civil engineers due to varied geological structures and material properties. Unlike soils, estimating rock mass bearing capacity using soil mechanics methods is often unsuitable due to irregular block dimensions. Factors like discontinuities, filling materials, and fracture intensity further complicate developing auniversal theory akin to Terzaghi’s for soils. Peck introduced a method correlating bearing capacity with Rock Quality Designation (RQD), followed by approaches based on Bieniawski’s Geomechanics Classification System and empirical methods. Despite advancements in numerical modelling, no universal solutions exist. This study analyzes fractured rock behaviour using Chilean site samples, employing finite element models to compute shear stresses and deformations. The goal is to propose a comparative method integrating empirical and numerical approaches, evaluating result dispersion.

Aim: To determine the prevalence of non-communicable diseases (NCDs) in chilean individuals suffering from periodontitis, stratifying them according to the severity of their periodontal condition. Presence of non-communicable diseases in a Chilean population with periodontitis. Methods: This study utilized a quantitative, cross-sectional,  observational design. Patients registered at the Periodontics Clinic of the Universidad Andrés Bello were included. Records of patients aged 18 years old with complete clinical history, medical-dental records, and full periodontogram were analyzed from March 2017 to May 2018. The periodontal diagnosis was established following the Page classification, categorized as mild or absent, moderate, and severe. The presence or absence of NCDs was documented. NCDs were grouped into: diabetes, cardiovascular conditions, pregnancy complications, respiratory diseases, kidney problems, rheumatoid arthritis, cognitive disorders, obesity, cancer, dyslipidemias, and psoriasis. The calculation of absolute frequencies was performed using Prism-GraphPad statistical software. Results: This study encompassed a cohort of 152 individuals, predominantly female, with an average age of 39.8  ±14.8 years. Notably, 59.86% displayed severe periodontitis, 21.71% had moderate periodontitis, and 18% exhibited mild or absent periodontitis. In terms of NCDs, 32.9% of the total participants were afflicted, with diabetes (11.84%), cardiovascular conditions (9.87%), and obesity (4.61%) emerging as the prevailing culprits. It is noteworthy that diabetes, cardiovascular disease, and obesity showed a higher incidence among patients with the mild form of periodontitis. Conclusion: In this examined population of individuals with periodontitis, a significant prevalence of 32.9% for NCDs was evident, with cardiovascular diseases and diabetes emerging as the predominant types.

Objective: To carry out a systematic review on the comparison of dental wear exerted by monolithic zirconia crowns and metal-porcelain crowns on opposing natural teeth. Materials and methods: A systematic search was carried out on different databases (Pubmed, Scopus, Google Scholar and Scielo) and 6 articles were selected, of which 4 were in vivo studies, and 2 were in vitro. Results: In 2 in vivo studies, the monolithic zirconia crown exerted less wear than the metallo-ceramic crown in the 1-year control. One in vivo study indicates that monolithic zirconia exerts less wear on the opposing natural tooth in a 6-month follow-up, but exerts greater wear than ceramic metal after one year. Other in vivo study indicates that monolithic zirconia exerts greater wear than ceramic metal in 6-month and 1-year controls. In vitro studies indicate that the monolithic zirconia crown causes less wear on the opposing natural tooth between 240,000 to 250,000 chewing cycles, which is equivalent to 1 year. Conclusions: Both monolithic zirconia crowns and metal-ceramic crowns behave well within the masticatory system, although studies show that the monolithic zirconia crown would exert less wear on the opposing tooth, there are other factors that influence wear, such as final finish of the crown, for example: glazed or polished. Intraoral scanning would be a more precise method for quantifying wear, since it prevents the impression-taking procedure. A follow-up of more than 1 year is suggested in future investigations related to the subject, in order to corroborate if the same results are maintained or could be different.

Introducción: Las fracturas de órbita representan entre el 24 % y el 36 % de todas las fracturas en la región maxilofacial, siendo las máscomunes aquellas que afectan el piso de la órbita (26 %). Tradicionalmente, el estándar de oro para la reconstrucción de estas fracturas ha sido el uso de mallas de titanio. No obstante, la malla Marlex se presenta como una alternativa viable para el manejo quirúrgico. Objetivos: El objetivo principal consiste en revisar la etiopatogenia de las fracturas del piso de la órbita y evaluar la malla  Marlex como una opción para el tratamiento quirúrgico, destacando sus ventajas mecánicas, biológicas y su fácil manipulación. Resultados: La malla Marlex, fabricada en polietileno, posee excelentes propiedades mecánicas, tales como alta estabilidad y resistencia a la deformación. Además, es una malla no absorbible que se manipula con facilidad; se adapta bien a la forma del defecto y puede  cortarse con tijeras según sea necesario. Esta malla no solo refuerza la zona afectada, sino que también facilita la formación de tejido óseo, al tiempo que proporciona soporte mecánico. Caso clínico: Un paciente masculino con una lesión significativa en los tejidos  blandos de la región infraorbitaria derecha se trató inicialmente con una sutura de espesor total en urgencias. Después, fue derivado al servicio de cirugía maxilofacial del Instituto Traumatológico, donde se le diagnosticó una fractura del piso de la órbita derecha. El  abordaje quirúrgico se realizó a través de esta herida para efectuar la plastia y suturar por planos, utilizando una malla de Marlex para reparar la fractura. Conclusiones: Aunque la malla de titanio es el estándar de oro, es esencial considerar alternativas como la malla  Marlex, debido a sus notables virtudes biológicas y mecánicas. Esta malla ofrece resultados quirúrgicos y posoperatorios excelentes para  el paciente.

Introduction: Nasal bone fractures represent one of the most prevalent facial injuries in adults, largely attributable to the nose’s prominent and exposed anatomical position. These fractures constitute approximately 40% of all facial fractures and are frequently result of high-impact events, such as motor vehicle collisions, sports-related trauma, and interpersonal violence. Given the nose’s integral role in both facial aesthetics and respiratory function, the management of nasal fractures is fundamental to ensure optimal outcomes in both cosmetic appearance and functional restoration.Objective: The aim of this paper is to present a step-by-step guide for perform a closed nasal reduction, using the clinical case of a patient with a nasal fracture as an example, along with a brief literature review on efficacy, aesthetic and functional considerations, and appropriate timing for intervention. Case presentation: A 47-year-old male patient presented to the emergency department with a nasal bone fracture sustained during an assault. Upon evaluation, the fracture was deemed suitable for management through closed reduction. A detailed step-by-step description of the closed reduction technique for nasal fractures, performed on the patient as an example, is provided. Post-procedure care included the use of internal and external splints, as well as a regimen of antibiotics and anti-inflammatory medications. Conclusion: Closed nasal reduction remains a widely used and effective procedure in the treatment of nasal bone fractures, particularly when performed early after injury. The procedure is minimally invasive and can yield satisfactory aesthetic and functional outcomes. However, its success depends on factors such as the timing of the intervention and the surgeon’s experience. While closed reduction is effective for most simple fractures, more complex cases may require additional surgical interventions, such as nasal osteotomy, particularly if bone fusion has already occurred. The management of nasal fractures is an elementary skill that maxillofacial surgeons must have, given the prevalence of these injuries in emergency settings.

Introduction: Currently, the market offers Bulk Fill resins that are used with the monobloc or single-increment technique (up to 4 or 5 mm). These resins are characterized by a lower filler content and larger filler particles, improved translucency, and a different chemical structure of the monomers in the filler compounds, which—when placed in a single block—reduce polymerization stress. Objective: To evaluate the level of marginal microleakage of two Bulk Fill resins using the deproteinization technique prior to acid etching. Methods: This is an in vitro study in which 64 extracted premolars underwent standardized cavity preparations. The teeth were randomly divided into four groups and subjected to a manual thermocycling process of 500 cycles. All samples were immersed in a 2% methylene blue solution for 24 hours. Microleakage was then observed with a stereomicroscope. Results: For the Aura Bulk Fill resin, microleakage in enamel was observed in 25% of the deproteinized samples and in 18.8% of the non-deproteinized samples. For the Filtek Bulk Fill resin, 31.3% of the samples exhibited microleakage in enamel with the deproteinization technique and 25.0% without deproteinization. No statistically significant differences were found. Conclusions: All samples presented microleakage, with similar levels in both brands of Bulk Fill resins, and no significant differences were observed with the application of the deproteinization technique.