Evaluation of Marginal Seal and Microleakage of a Sealant Modified with Silver Nanoparticles in Primary Molars

ABSTRACT The objective of this study was to evaluate the marginal seal effectiveness and microleakage of a pit and fissure sealant containing silver nanoparticles (AgNPs). An experimental in vitro study was carried out using 40 extracted temporary molars without caries or incipient caries. These molars were divided into two groups: Group A (20 molars), to which a silver nanoparticle-containing sealant was applied, and Group B (20 molars), to which a conventional sealant was applied. The marginal seal and microleakage were evaluated. No significant differences in the marginal seal or microleakage were noted between the silver nanoparticle-containing sealant and the conventional sealant.The addition of AgNPs does not alter the adhesion or resistance of the sealant. RESUMEN El objetivo del presente estudio fue evaluar la efectividad del sellado marginal y microfiltración de un sellador de fosetas y fisuras con contenido de nanopartículas de plata (AgNPs). Para esto, se realizó un estudio experimental in vitro usando 40 molares temporales extraídos sin caries o con caries incipiente. Estos molares fueron divididos en dos grupos: Grupo A (20 molares), a los cuales se les aplicó sellador adicionado con nanopartículas de plata, y Grupo B (20 molares), a los cuales se les aplicó el sellador convencional. Se evaluaron el sellado marginal y la microfiltración. No se encontraron diferencias significativas en el sellado marginal y microfiltración entre el sellador adicionado con nanopartículas de plata y el sellador convencional. Basados en los resultados obtenidos a partir de este estudio concluimos que la adición de AgNPs no altera la adhesión o la resistencia del sellador. PALABRAS CLAVE Caries, Sellador, Prevención, Nanopartículas de plata

La paleodieta de cinco especies de mamíferos herbívoros rancholabreanos de valsequillo (Puebla, México)

Through the use of the 13C/12C and 18O/16O isotopic relationships found at enamel and osteodentine, here it is inferred the diet and preferred habitat in which five extinct herbivore species from the Late Pleistocene of Valsequillo, Puebla, México. The horses, mammoths, and sloths showed a diet mainly based in C4, meanwhile the capybaraand gomphotheres were mixed C3/C4 feeders. The vegetation in which those animals lived was open with some trees, similar to the one proposed in other studies based in some macromammals species found in the locality.Usando las relaciones isotópicas de 13C/12C y 18O/16O presentes en el esmalte y la osteodentina, se infirió la dieta y el ambiente en el cual vivieron cinco especies extintas de herbívoros procedentes del Pleistoceno Tardío de Valsequillo, Puebla, México. Los caballos, los mamutes y el perezoso mostraban una dieta basada exclusivamente en plantas C4, mientras que el carpincho y los gonfoterios exhibían una dieta mixta C3/C4. El tipo de vegetación en el cual estos animales habitaron fue abierto con poca cobertura arbórea, misma que ha sido propuesta en otros estudios usando la presencia de algunas especies de micromamíferos encontradosen la zona

Confined benzene within InOF-1: Contrasting CO2 and SO2 capture behaviours

The confinement of small amounts of benzene in InOF-1 (Bz@InOF-1) shows a contradictory behavior in the capture of CO2 and SO2. While the capture of CO2 is increased 1.6 times, compared to the pristine material, the capture of SO2 shows a considerable decrease. To elucidate these behaviors, the interactions of CO2 and SO2 with Bz@InOF-1 were studied by DFT periodical calculations postulating a plausible explanation: (a) in the case of benzene and CO2, these molecules do not compete for the preferential adsorption sites within InOF-1, providing a cooperative CO2 capture enhancement and (b) benzene and SO2 strongly compete for these preferential adsorption sites inside the MOF material, reducing the total SO2 capture

Risk of Dengue Incidence in Children and Adolescents in Zulia, Venezuela, using a Negative Binomial Generalized Linear Mixed Model

Introduction: Dengue is the most important arboviral disease. Its incidence has increased 30-fold over the last 50 years, causing global concerns. Studies have showed children to be the most vulnerable. Methods: Observational study using dengue cases from Zulia state, Venezuela, modelling through a Negative Binomial Generalized Linear Mixed Model (GLMM) accounting for heterogeneity in the variance via a hierarchical Bayesian framework, was done. We assessed risk factors such as age and sex. The Bayesian framework enabled the estimation of Relative Risk (RR) and a Binomial regression was run using the WinBUGS software. Results: During 2002-2008, there were 49,330 cases of dengue in Zulia state, Venezuela. Most of them (18.71%) in 2007. The model revealed that children aged from 5 to 14 y-old had 1.59-higher risk (95%CI 1.41-1.79) compared with those aged from 0-4 y-old. Those aged 25-44 years old and ≥45, have significantly less RR than the baseline category, RR 0.5228 (95%CI 0.46-0.59) and 0.3069 (95%CI 0.27-0.34). Conclusions: The findings confirmed that groups most at risk were children aged 5 to 14 years. Modelling and predicting dengue epidemiology are still a need in multiple countries, especially those at risk of newer epidemics, as is the case of Zulia and Venezuela

Risk of Dengue Incidence in Children and Adolescents in Zulia, Venezuela, using a Negative Binomial Generalized Linear Mixed Model

Introduction: Dengue is the most important arboviral disease. Its incidence has increased 30-fold over the last 50 years, causing global concerns. Studies have showed children to be the most vulnerable. Methods: Observational study using dengue cases from Zulia state, Venezuela, modelling through a Negative Binomial Generalized Linear Mixed Model (GLMM) accounting for heterogeneity in the variance via a hierarchical Bayesian framework, was done. We assessed risk factors such as age and sex. The Bayesian framework enabled the estimation of Relative Risk (RR) and a Binomial regression was run using the WinBUGS software. Results: During 2002-2008, there were 49,330 cases of dengue in Zulia state, Venezuela. Most of them (18.71%) in 2007. The model revealed that children aged from 5 to 14 y-old had 1.59-higher risk (95%CI 1.41-1.79) compared with those aged from 0-4 y-old. Those aged 25-44 years old and ≥45, have significantly less RR than the baseline category, RR 0.5228 (95%CI 0.46-0.59) and 0.3069 (95%CI 0.27-0.34). Conclusions: The findings confirmed that groups most at risk were children aged 5 to 14 years. Modelling and predicting dengue epidemiology are still a need in multiple countries, especially those at risk of newer epidemics, as is the case of Zulia and Venezuela

Feeding habits and habitat of herbivorous mammals from the Early–Late Hemphillian (Miocene) of Costa Rica

Carbon and oxygen stable isotope values in the dental enamel of fossils were used to infer the diet and habitat of the extinct equids Calippus hondurensis, Dinohippus mexicanus, and Protohippus gidleyi, the gomphothere Gomphotherium hondurensis, and the llama Hemiauchenia vera of the Early–Late Hemphillian (Hh2) from San Gerardo de Limoncito, Puntarenas province, Costa Rica. The results suggest that these mammals fed mainly on C3 plants and lived in clearings of rainforests. This contrasts with previous studies from North America that indicated that the same species lived in forest savannas and fed mainly on C4 plants, but it is similar to the results obtained from the palynological record of the area, as well as with several vegetation models suggesting the presence of humid tropical forest during the Miocene in Central America