Insertion methods and gap/void formation in atraumatic restorative technique: A micro-CT analysis

Abstract Wetting the dentin is critical to atraumatic restorative treatment. The conventional insertion can be challenging when using high-viscosity glass-ionomer cement. This study evaluated the formation of gaps and voids after three insertion methods using micro-CT. Teeth underwent removal of occlusal and proximal caries through the atraumatic restorative treatment technique. Then, they were fixed in an artificial dental arch to simulate the clinical condition and were restored using three insertion methods: conventional, Centrix injection, and double-filling. Previous dentin conditioning procedures, steel matrix and wooden wedge application, and post-insertion procedures (digital compression and surface protection) were the same. The material was inserted using a manual instrument in the conventional technique and was inserted with a syringe in the Centrix injection group. In the double-filling technique, the tooth received a first layer of a flowable ionomer (through modifying the powder/liquid ratio), and a second layer (with standard ratio) was applied before the final set of the first one. A micro-CT unit scanned each tooth before and after restoration. Each cavity was defined as the volume of interest, and the volumes of gaps and voids were calculated. Data were analyzed using one-way ANOVA and Tukey posthoc test (p < .05). Double-filling had improved filling volume with lower values for gap volume, followed by Centrix injection. The conventional technique had the highest gap volume. No statistically significant difference was observed for void volume. Double-filling demonstrated fewer gaps, followed by Centrix injection, which is critical to obtain better adhesive, remineralizing, and antibacterial activities.

Resumo O molhamento da dentina parcialmente desmineralizada no fundo da cavidade dentária é fundamental para o sucesso do tratamento restaurador atraumático. No entanto, o método de inserção convencional pode ser desafiador ao usar cimento de ionômero de vidro de alta viscosidade. Este estudo avaliou a formação de gaps e vazios internos após três métodos de inserção de cimento de ionômero de vidro de alta viscosidade usando micro-CT. Dez terceiros molares foram submetidos à remoção de cárie oclusal através da técnica de tratamento restaurador atraumático e complementação proximal (com ou sem lesão pré-existente). Em seguida, foram fixados em uma arcada dentária artificial para simular a condição clínica. Os dentes foram restaurados usando a técnica de tratamento restaurador atraumático com três métodos de inserção: convencional, injeção Centrix e dupla inserção. Os procedimentos anteriores de condicionamento dentinário, inserção de matriz de aço, aplicação de cunha de madeira e procedimentos pós-inserção do material (como compressão digital e proteção de superfície) foram os mesmos para os três grupos testados. O material foi inserido com instrumento manual na técnica convencional, seguindo a metodologia clássica do tratamento restaurador atraumático. O material foi inserido com um dispositivo desenvolvido especificamente para esse fim na técnica de inserção com seringa tipo Centrix. Na técnica de dupla obturação, o dente recebeu uma primeira camada do cimento de ionômero de vidro mais fluido (obtido através da modificação da relação pó/líquido), e uma segunda camada (com relação pó/líquido padrão) foi aplicada antes da presa final da primeira. Um micro-CT escaneou cada dente antes e depois da restauração. Cada cavidade foi definida como o volume de interesse, e os volumes de gaps e vazios foram calculados. Os dados foram analisados por ANOVA one-way e teste post-hoc de Tukey com nível de significância de 5%. A dupla inserção melhorou significativamente o volume de preenchimento com valores percentuais mais baixos para o volume do gap, seguido pela injeção com seringa tipo Centrix. A técnica convencional apresentou o maior percentual de volume de gap. Nenhuma diferença estatisticamente significativa foi observada para o volume de vazios internos. O grupo de dupla inserção demonstrou menor formação de gaps, seguido pelo grupo de injeção com seringa tipo Centrix, que é fundamental para obter melhores atividades adesivas, remineralizantes e antibacterianas.

X-Ray Microtomography Analysis of Gaps and Voids in the Restoration of Non-Carious Cervical Lesions with Different Composite Resins

Context (Background): Resin composites are the most widely used material for restoring cervical defects. However, the high failure rate of these restorations is still a concern. Aims: The aim of this in vitro study was to evaluate, using microtomography (?CT), the interfacial gap and voids formation in Class V cavities in premolars restored with materials with lower polymerization shrinkage combined with different restorative techniques. Settings and Design: Cervical defects were created in 30 intact premolar and were randomly distributed to be restored by one of the following techniques (n = 6): Composite resin with two increments (CR), organic modified polymer (ORMOCER) with single (OR1) or two increments (OR2, or low viscosity bulk?fill composite resin with single (BF1) or two increments (BF2). Methods and Material: Each tooth was scanned before filling to determine the volume of interest (VOI) to be applied in the second ?CT after restoration and to control the cavity volume among the groups. In the ?CT after filling, the volume of interfacial gaps and voids was calculated for each group. Statistical Analysis: The groups were compared using one?way and Tukey HSD post hoc test (? = 0.05). Results: It was possible to identify higher gap formation in the OR1 group and higher void formation in CR group (P < 0.05). OR2 group showed better results than the group with one increment. BF2 showed the best filling capacity. Conclusions: It was possible to conclude that the material and the number of increments directly influenced the internal adaptation and voids formation of Class V restorations.

Leak and Scattering Assessment by Optically Stimulated Luminescence Dosimetry in a Helical Linear Accelerator / Valoración de Fuga y Dispersión por medio de Dosimetría de Luminiscencia Estimulada Ópticamente (OSL) en un Acelerador Lineal Helicoidal

Radiation absorbed doses to organs outside the radiation therapy treatment beam can be significant and therefore of clinical interest. Two sets of out-of-beam measurements were performed measuring the leak dose and the scattered dose, at 5 points within the accelerator components (accelerator tube and collimator) and at 21 points on the equipment and surroundings based on a positioning scheme. For this purpose, 52 Optically Stimulated Luminescence (OSL) dosimeters were used in a latest generation helical linear accelerator. Of the 200 cGy fired at a cheese-like phantom, 0.332% of the out-of-beam dose contribution was found to come from the leak and 0.784% was transformed into scattering. For these dose values, estimates of the risk of second tumors in long-term survivors indicate a reduced probability of acquiring a second secondary radiation malignancy, based on information from the 1990 BEIR Committee report.

La dosis absorbida de radiación a órganos fuera del haz de tratamiento de radioterapia puede ser significativa y, por lo tanto, de interés clínico. Se realizaron dos sets de mediciones fuera del haz para determinar la dosis de fuga y la dosis dispersa, en 5 puntos dentro de los componentes del acelerador (tubo de aceleración y colimador) y 21 puntos en el equipo y alrededores basado en un esquema de posicionamiento. Para este fin se utilizaron 52 dosímetros de luminiscencia estimulada ópticamente (OSL, Optically Stimulated Luminescence), en un acelerador lineal helicoidal de última generación. De los 200 cGy disparados a un maniquí tipo queso, se encontró que el 0.332% de la contribución de dosis fuera del haz provenía de la fuga y 0.784% se transforma en dispersión. Para estos valores de dosis, las estimaciones del riesgo de segundos tumores en los supervivientes a largo plazo indican una reducida probabilidad de contraer una segunda malignidad por radiación secundaria, según la información del informe del Comité BEIR de 1990.

Calidad del Sueño, Estrés Percibido y Desórdenes Temporomandibulares Dolorosos en Adultos Jóvenes de Dos Comunidades Mexicanas

RESUMEN: Una mala calidad del sueño y estrés, pueden ser la génesis de anomalías temporomandibulares que consisten en una familia heterogénea de desórdenes músculoesqueletales que representan la afección de dolor orofacial crónica más común. El objetivo de este trabajo fue relacionar la calidad del sueño, estrés percibido y desórdenes temporomandibulares dolorosos en adultos jóvenes de dos comunidades mexicanas (Puebla y Yucatán). Material y Métodos: estudio de tipo correlacional, analítico, prospectivo, de corte transversal. Se obtuvo consentimiento informado y voluntario por medio de firmas de 552 sujetos adultos jóvenes: 276 de Puebla (P), 53 % (n=147) mujeres, 47 % (n= 129) hombres, con un promedio de 28 años (± 4,5); y 276 sujetos de Yucatán (Y), 58 % (n=161) mujeres, 42 % (n= 115) hombres, con un promedio de 27 años (±4,9). Se les realizó entrevistas con base a tres cuestionarios: Índice de Calidad de Sueño de Pittsburg (ICSP), Escala de Estrés Percibido de Cohen (EEP) e Instrumento de Examinación de Desórdenes Temporomandibulares Doloroso de González (IEDTD). Para el análisis estadístico se utilizó estadística descriptiva (frecuencias y porcentajes), regresión logística y correlación de Pearson. Puebla presenta un porcentaje mayor de individuos con calidad de sueño pobre 83 %, comparado con Yucatán, 56 %. De la misma forma, Puebla muestra un porcentaje mayor de individuos con estrés alto, 82 %, comparado con Yucatán, 74 %. Por otro lado, Puebla presenta un porcentaje mayor de individuos con DTM dolorosos, 33 %, comparado con Yucatán, 11 %. Asimismo, existe una correlación moderada general entre el estrés percibido y la calidad del sueño en mujeres (0,335) y edades de 30 a 35 años (0,383) ambas con una significancia de p <0,001. La calidad de sueño pobre aumenta 4 veces la posibilidad de padecer un DTM doloroso. Vivir en Puebla aumenta hasta 3.1 veces la posibilidad de un DTM doloroso.

ABSTRACT: Por sleep quality and stress may be the génesis of temporomandibular disorders that consist of a heterogeneous family of musculoskeletal disorders that represent the most common chronic orofacial pain condition. The objective of the study was to relate sleep quality, perceived stress, and painful temporomandibular disorders in Young adults from two Mexican communities (Puebla and Yucatán). a correlational, analytical, prospective, cross- sectional study. Informed and voluntary consent was obtained through the signatures of 552 young adult subjects: 276 from Puebla (P), 53 % (n = 147) women, 47 % (n = 129) men, with an average of 28 years (± 4.5); and 276 subjects from Yucatán (Y), 58 % (n = 161) women, 42 % (n = 115) men, with an average age of 27 years (±4.9). Interviews were conducted based on three questionnaires: Pittsburg Sleep Quality Index (ICSP), Cohen's Perceived Stress Scale (EEP) and González's Painful Temporomandibular Disorders Examination Instrument (IEDTD). Descriptive statistics (frequencies and percentages), logistic regression and Pearson's correlation were used for statistical analysis. Puebla has a higher percentage of individuals with por sleep quality, 83 %, compared to Yucatán, 56 %. In the same way, Puebla shows a higher percentage of individuals with high stress, 82 %, compared to Yucatán, 74 %. On the other hand, Puebla has a higher percentage of individuals with painful TMD, 33 %, compared to Yucatán, 11 %. Likewise, there is a general moderate correlation between perceived stress and sleep quality in women (0.335) and ages 30 to 35 years (0.383), both with a significance of p <.001. Poor sleep quality increases the chance of painful TMD by 4 times. Living in Puebla increases the possibility of painful TMD up to 3.1 times.

Actividad antibacteriana in vitro del extracto hidroetanólico de Myrciaria dubia (Kunth) McVaugh (camu camu) sobre Streptococcus mutans / In vitro antibacterial activity of hydroethanolic extract from Myrciaria dubia (Kunth) McVaugh (camu camu) against Streptococcus mutans

Introducción: Streptococcus mutans participa en el origen y progreso de la caries dental, una de las enfermedades más prevalentes a nivel mundial. Su control requiere métodos seguros y accesibles para la población. Myrciaria dubia (Kunth) McVaugh (Myrtaceae) (camu camu) es un árbol nativo de la amazonía peruana. La capacidad antimicrobiana de los componentes de su fruto ya se ha comprobado. Objetivo: Evaluar la actividad antibacteriana in vitro del extracto hidroetanólico de M. dubia contra S. mutans ATCC 35658. Métodos: Investigación experimental con posprueba y grupos controles. El extracto de la pulpa del fruto de M. dubia se obtuvo mediante maceración hidroetanólica. Las concentraciones evaluadas fueron 25 mg/mL, 50 mg/mL y 75 mg/mL. La capacidad antibacteriana se determinó mediante el método de difusión en disco. Gluconato de clorhexidina 0,12 por ciento fue el control positivo y el dimetilsulfóxido al 1 por ciento el control negativo. Resultados: La actividad antibacteriana se incrementó de manera directamente proporcional a la concentración del extracto. La concentración de 75 mg/mL mostró una media de inhibición de 18,2 ± 0,774 mm, seguido de la concentración de 50 mg/mL con una media de inhibición de 14,6 ± 1,055 mm y la concentración de 25 mg/mL con un halo de inhibición promedio de 10,1± 0,833 mm. La zona de inhibición del control positivo fue de 16,5 ± 0,516 mm. Existe diferencia estadísticamente significativa entre la concentración de 75 mg/mL y el control positivo (p< 0,05). Conclusiones: El extracto hidroetanólico de M. dubia muestra actividad antibacteriana in vitro de tipo bactericida sobre S. mutans ATCC 35668(AU)

Introduction: Streptococcus mutans is involved in the genesis and progress of dental caries, one of the most prevalent diseases worldwide, whose control requires safe methods accessible to the population. Myrciaria dubia (Kunth) McVaugh (Myrtaceae) (camu camu) is a tree native to the Peruvian Amazon. The antimicrobial capacity of the components of its fruit has already been verified. Objective: Evaluate the in vitro antibacterial activity of M. dubia hydroethanolic extract against S. mutans ATCC 35658. Methods: An experimental study was conducted with post-test analysis and control groups. The extract from the pulp of the fruit of M. dubia was obtained by hydroethanolic maceration. The concentrations evaluated were 25 mg/mL, 50 mg/mL and 75 mg/mL. Antibacterial capacity was determined by the disc diffusion method. The positive control was 0.12 percent chlorhexidine gluconate, whereas the negative control was 1 percent dimethyl sulfoxide. Results: The antibacterial activity increased directly proportional to the concentration of the extract. The concentration of 75 mg/mL showed a mean inhibition of 18.2 ± 0.774 mm, followed by the concentration of 50 mg/mL with a mean inhibition of 14.6 ± 1.055 mm and the concentration of 25 mg/mL with an average inhibition halo of 10.1 ± 0.833 mm. The zone of inhibition of the positive control was 16.5 ± 0.516 mm. There is a statistically significant difference between the concentration of 75 mg / mL and the positive control (p< 0.05). Conclusions: The M. dubia hydroethanolic extract displays in vitro antibacterial bactericidal activity against S. mutans ATCC 35668(AU)

Distribution of polymorphism rs693 of ApoB gene in a sample of Colombian Caribbeans / Distribución del polimorfismo rs693 en el gen de la apolipoproteína B en una muestra caribeños colombianos

Abstract Introduction: Several studies have reported that the single nucleotide polymorphism rs693 of Apo lipoprotein B gene is associated with high levels of plasma lipids and high body mass index, which are risk factors for cardiovascular diseases. The distribution of this single nucleotide polymorphism and its association with the phenotype depend on the genetic background of each population. Objective: To evaluate the distribution of single nucleotide polymorphism rs693 and its association with lipid profile and body mass index in a sample of Colombian Caribbeans. Methods: 108 non-related adult subjects of both gender were included in this study. Body mass index and lipid profile that included total cholesterol, triglycerides, Low Density Lipoprotein and High Density Lipoprotein were determined. The single nucleotide polymorphism rs693 was determined by Polymerase Chain Reaction/Restriction Fragment Length Polymorphism from genomic DNA followed by digestion with the restriction enzyme XbaI. The chi-square test was used to analyze the genotype distribution of rs693 and the genotype-phenotype association was evaluated through different inheritance model. Results: The genotype frequencies for single nucleotide polymorphism rs693 were CC (45.0%), TT (16.5%) and CT (38.5%). The allele frequencies were C (64.0%) and T (36.0%). The single nucleotide polymorphism was in Hardy-Weinberg equilibrium in the studied sample. No association of the single nucleotide polymorphism rs693 with lipid profile nor the body mass index was found (p >0.05). Conclusion: There is no significant association between single nucleotide polymorphism rs693 and body mass index nor lipid profile, in a sample of Colombian Caribbeans.

Resumen Introducción: Varios estudios han informado que el polimorfismo de un solo nucleótido rs693 del gen de la apolipoproteína B se asocia con altos niveles de lípidos plasmáticos e índice de masa corporal, los cuales son factores de riesgo para enfermedades cardiovasculares. La distribución de este polimorfismo y su asociación con el fenotipo dependen del antecedente genético de cada población. La población caribeña colombiana es producto de la mezcla de tres grupos étnicos principales: africano, amerindio y caucásico. Objetivo: Evaluar la distribución del polimorfismo rs693 y su asociación con el perfil lipídico y el índice de masa corporal en una muestra de sujetos caribeños colombianos. Métodos: Fueron incluidos en este estudio 108 sujetos adultos de ambos sexos y no relacionados. Se determinaron el índice de masa corporal y el perfil lipídico; de éste se incluyó colesterol total, triglicéridos, lipoproteínas de baja densidad y lipoproteína de alta densidad. El polimorfismo rs693 se determinó mediante Reacción en Cadena de la Polimerasa del ADN genómico seguida por digestión con la enzima de restricción XbaI. Se utilizó la prueba de ji cuadrado para analizar la distribución del genotipo de rs693 y se evaluó la asociación genotipo-fenotipo a través de diferentes modelos de herencia. Resultados: Las frecuencias genotípicas para rs693 fueron CC (45.0%), TT (16.5%) y TC (38.5%). Las frecuencias alélicas fueron C (64.0%) y T (36.0%). El polimorfismo rs693 estaba en equilibrio de Hardy-Weinberg en la muestra estudiada y no presentó asociación con el perfil lipídico ni con el índice de masa corporal (p >0.05). Conclusión: No existe asociación significativa del polimorfismo rs693 con el índice de masa corporal ni con el perfil lipídico en una muestra de caribeños colombianos.

Micro-shear bond strength of composite resin to glass ionomer cement using an alternative method to build up test specimens

Despite the relevance of the sandwich technique, there are still doubts about the best adhesive strategy and surface treatment for glass ionomer cements (GICs). Aim: The aim of this study is to evaluate the best surface treatment for GIC to ensure an effective and durable adhesion to resin, through micro-shear test, using an alternative method to build up test specimens. Subjects and Methods: Eighty GIC samples were divided into eight groups (n = 10) according to five surface treatments (none, etching, air drying, grinding, and grinding plus etching) and according to the adhesive system (conventional or self-etch). Five starch tubes were positioned on each sample, and a flowable composite was inserted generating 50 resin test bodies per group and a total of 400 tested areas. All specimens were submitted to the micro-shear test: half immediately and half after thermal cycling (10,000 cycles of 20 s each/5° and 55°C). All samples were analyzed to evaluate fracture. Representative samples were also analyzed by scanning electron microscopy and energy dispersive spectroscopy. Data were analyzed with two-way ANOVA and Tukey's honest significant difference post hoc test (P <.05). Results: The bond strengths in the thermal cycled specimens were lower and showed a statistically significant difference (P = 0). The “grinding” groups showed the highest bond strength. Conclusions: The alternative method to build up test specimens was effective and easy to execute. Grinding of the GIC surface, which is not normally performed before the use of the adhesive system, represented the best option of surface treatment.

Influence of iron and copper on the activity of laccases in Fusarium oxysporum f. sp. lycopersici

ABSTRACT Fusarium oxysporum f. sp. lycopersici is a phytopathogenic fungus that causes vascular wilt in tomato plants. In this work we analyze the influence of metal salts such as iron and copper sulphate, as well as that of bathophenanthrolinedisulfonic acid (iron chelator) and bathocuproinedisulfonic acid (copper chelator) on the activity of laccases in the intra (IF) and extracellular fractions (EF) of the wild-type and the non-pathogenic mutant strain (rho1::hyg) of F. oxysporum. The results show that laccase activity in the IF fraction of the wild and mutant strain increased with the addition of iron chelator (53.4 and 114.32%; respectively). With copper, it is observed that there is an inhibition of the activity with the addition of CuSO4 for the EF of the wild and mutant strain (reduction of 82 and 62.6%; respectively) and for the IF of the mutant strain (54.8%). With the copper chelator a less laccase activity in the IF of the mutant strain was observed (reduction of 53.9%). The results obtained suggest a different regulation of intracellular laccases in the mutant strain compared with the wild type in presence of CuSO4 and copper chelator which may be due to the mutation in the rho gene.

Influence of iron and copper on the activity of laccases in Fusarium oxysporum f. sp. lycopersici

ABSTRACT Fusarium oxysporum f. sp. lycopersici is a phytopathogenic fungus that causes vascular wilt in tomato plants. In this work we analyze the influence of metal salts such as iron and copper sulphate, as well as that of bathophenanthrolinedisulfonic acid (iron chelator) and bathocuproinedisulfonic acid (copper chelator) on the activity of laccases in the intra (IF) and extracellular fractions (EF) of the wild-type and the non-pathogenic mutant strain (rho1::hyg) of F. oxysporum. The results show that laccase activity in the IF fraction of the wild and mutant strain increased with the addition of iron chelator (53.4 and 114.32%; respectively). With copper, it is observed that there is an inhibition of the activity with the addition of CuSO4 for the EF of the wild and mutant strain (reduction of 82 and 62.6%; respectively) and for the IF of the mutant strain (54.8%). With the copper chelator a less laccase activity in the IF of the mutant strain was observed (reduction of 53.9%). The results obtained suggest a different regulation of intracellular laccases in the mutant strain compared with the wild type in presence of CuSO4 and copper chelator which may be due to the mutation in the rho gene.

Trastornos de la conducta alimentaria en estudiantes de medicina de una universidad de Perú / Eating disorders in medical students of a Peruvian university

Introducción: Los trastornos de la conducta alimentaria afectan con mayor frecuencia a jóvenes, y pueden llegar a tener importantes consecuencias en su salud mental y física. Objetivo: Determinar la prevalencia de probable diagnóstico de trastornos de conducta alimentaria en estudiantes de medicina y sus factores asociados. Métodos: Estudio descriptivo transversal realizado en estudiantes de medicina del primer año de una universidad de Lima, Perú. Se aplicó un cuestionario virtual para recolectar los datos de interés. Aquellos con un puntaje ≥20 en elEatingAttitudes Test-26, se consideronconprobable diagnóstico de trastornos de conducta alimentaria.Para evaluar los factores se calcularon razones de prevalencia y intervalos de confianza al 95% usando regresiones de Poissoncrudas con varianza robusta. Resultados: Del total de 440 estudiantes de primer año, 375 (85,2 por ciento) completaron la encuesta. La prevalencia de probable diagnóstico de trastornos de conducta alimentaria fue de 10,1 por ciento (11,3 en mujeres y 8,6 en varones).Los factores asociados a esta variable fueron: rechazo escolar por trastornos nutricionales, rechazo laboral por la delgadez, rechazo social cercano por la imagen corporal, influencia familiar sobre la imagen corporal, influencia de la imagen corporal de modelos de pasarela e influencia de los anuncios televisivos de productos para adelgazar. Los dos últimos con los mayores valores de la razón de prevalencias. Conclusiones: Aproximadamente uno de cada diez estudiantes presentaprobable diagnóstico de trastornos de conducta alimentaria que se asocian con factores familiares, sociales,laborales y otros relacionados con los medios de comunicación(AU)

Introduction: Eating disorders affect mostly young persons, and may have important consequences on their mental and physical health. Objectives: To determine the probable diagnosis of eating disorders in medical students and to evaluate their associated factors. Methods: Descriptive and cross-sectional study performed in first-year medical students of a private university in Lima, Peru. An electronic survey was administrated to collect data of interest. Those students with a score ≥20 in the Eating Attitudes Test-26 were considered to have probable diagnosis of eating disorders. For assessment of associated factors, we calculated prevalence ratios and 95 percent confidence intervals using Poisson crude regressions with robust variance. Results: Of 440 first-year medical students, 375 (85.2 percent) completed our survey. The prevalence of probable diagnosis of eating disorders in the study population was 10.1 percent (11.3for females and 8.6for males). Associated factors to this variable were: school rejection due to nutritional disorders, job rejection due to thinness, social rejection of body image, family influence on body image, influence of fashion show models' body image and influence of TV advertisement of slimming products. The two latter reached the highest prevalence ratio values. Conclusions: Around one in ten students has a probable diagnosis of eating disorders associated with family, social, work and mass media-related factors(AU)

Photoprotective effect of verbascoside from Buddleja cordata in SKH-1 mice exposed to acute and chronic UV-B radiation / Efecto fotoprotector del verbascósido de Buddleja cordata en ratones SKH-1 expuestos de forma aguda y crónica a laradiación UV-B

Ultraviolet radiation (UVR) is involved in both sunburn and the development of skin cancer, which has a high incidence worldwide. Strategies to reduce these effects include the use of photoprotective substances. The aim of this work was to investigate the photoprotective effect of verbascoside isolated from the methanolic extract of Buddleja cordata (BCME) in SKH-1 mice exposed to acute and chronic UV-B radiation. The mouse dorsal area was evaluated macroscopically and microscopically for diagnosis; verbascoside penetration into mouse skin was investigated in vivo by the tape stripping method. After acute UV-B exposure, 100 percent of irradiated mice that had been protected with verbascoside showed no signs of sunburn or of inflammatory processes. After chronic exposure, 100 percent of unprotected mice showed skin carcinomas; in contrast, in mice topically treated with either BCME or verbascoside, the presence of lesions was decreased by 90 percent. These results prove that verbascoside penetrates through the skin of mice and suggest that verbascoside and BCME may potentially prevent photodamage on mice’s skin after acute and chronic UVR exposure.

La radiación ultravioleta (RUV) provoca quemaduras solares y el desarrollo de cáncer de piel. El objetivo de este trabajo fue investigar el efecto fotoprotector del verbascósido obtenido del extracto metanólico de Buddleja cordata (EMBC) en ratones SKH-1 expuestos a RUV-B de manera aguda y crónica. El diagnóstico histológico se llevó a cabo en la piel de la zona dorsal de los ratones. La penetración del verbascósido fue cuantificada mediante la técnica de la cinta adhesiva. En el experimento agudo, el 100 por ciento de los ratones protegidos con verbascósido no evidenciaron signos de quemadura ni procesos inflamatorios. En el experimento crónico los ratones sin protección e irradiados presentaron carcinomas cutáneos. En contraste en los ratones protegidos con EMBC o verbascósido las lesiones disminuyeron un 90 por ciento en ambos grupos. El verbascósido penetró en la piel del ratón. Los resultados sugieren que el EMBC y el verbascósido previenen el fotodaño en la piel de ratones expuestos de forma aguda o crónica a la RUV.

Avaliação da eficácia das fitas para clareamento dental / Evaluation of the Effectiveness of Dental Whitening Strips

O objetivo deste estudo foi discutir, através de uma revista da literatura, a eficácia, limitações e efeitos colaterais relacionados com as fitas para clareamento dental. Dentre os vários artigos apresentados neste estudo, todos relatam um efeito branqueador em esmalte e dentina com o uso de fitas clareadoras impregnadas com peróxido de hidrogênio entre 5% a 10%. Porém, pouco se sabe se o grau de clareamento atingido se equipara ao das demais técnicas clareadoras. Além disso, somente um estudo acompanhou a duração do resultado por três meses. Portanto, mais pesquisas são necessárias para avaliar o tempo total de duração do clareamento através do uso de fitas, assim como comprovar se o grau de clareamento alcançado pode ser comparável às outras técnicas.

The aim of this study was to discuss, through a literature review, the effectiveness, limitations and side effects related to tooth whitening strips. Among the various articles shown in this study, all of them describe a whitening effect on enamel and dentin using whitening strips impregnated with hydrogen peroxide between 5% and 10%. However, little is known whether the degree of whitening achieved is comparable to the effect produced by other bleaching techniques. Furthermore, only one study followed the length of the result for three months. Therefore, more research is needed to assess the full duration of whitening through the use of whitening strips, as well as demonstrate the degree of whitening that can be achieved compared to other techniques.

#Ladies y #gentlemen del DF: Dominancia social y actitudes hacia la discriminación / #Ladies & #Gentlemen of Mexico City: Social Dominance and Discriminatory Attitudes

La teoría de la dominancia social (SDO) explica el nivel en que las personas aceptan o rechazan las ideologías que le imprimen legitimidad a las jerarquías y la discriminación o a la igualdad y justicia. Este estudio aplica SDO en México y investiga si la dominancia social en abstracto tiene conexión con la aprobación de la discriminación en concreto (usando los casos de Lady de Profeco, Ladies de Polanco y Gentleman de las Lomas). Predecimos (1) que los hombres, los participantes de mayor edad y los que provienen de clases sociales más altas mostrarían niveles más altos de SDO; y (2) que la aprobación de discriminación será determinada por el nivel de SDO (alto > bajo) y por clase social (alta > media > baja). Participantes fueron N=150 miembros del publico en el DF. Llenaron cuestionarios en la calle, midiendo sexo, edad, lugar de residencia, SDO y aprobación de discriminación. Los resultados generalmente aportaron las hipótesis. Hombres tenían puntajes mas altos de SDO que mujeres, pero las clases sociales mas bajas que altas tenían niveles mas altos de SDO. Hubo una correlación positiva entre SDO y aprobación de discriminación. Los resultados se discutieron en términos de diferencias en educación y movilidad social.

Social dominance orientation/theory (SDO) explains the extent to which individuals accept or reject ideologies that legitimize hierarchies and discrimination or equality and social justice. Numerous studies have shown that SDO predicts a wide range of political, ideological, and intergroup phenomena, particularly in relation to negativity towards minorities and outgroups. The aims of the present study were to apply the SDO scale in a Mexican context; examine differences in SDO according to sex, age group, and social class; and investigate whether an orientation towards social dominance would be detectable not only on an abstract level but a concrete level, that of approving inter-class discrimination. We predicted that (1) SDO would be higher in men than women, older than younger participants, and upper rather than lower social classes, (2) that approval of discrimination would be determined by SDO and social class, and (3) that SDO would correlate with approval of discrimination. Participants were N=150 members of the public in Mexico City, with a mean age of 35.3 years (range: 18-74) and from areas of different social classes. Participants completed paper-and-pencil questionnaires on the street. We measured demographics (sex, age, place of residence), a 16-item SDO scale (e.g., "Some people are just more deserving than others") with a Cronbach's alpha of .83, and three instances of discriminatory behavior on the part of upper-class members towards lower-class members, alpha=.90, e.g.: "The behavior of the 'Ladies of Polanco' insulting a police officer is justified". All items were measured on 5-point Likert-type scales, from 1=strongly disagree to 5=strongly agree. Results were generally in line with the hypotheses. A three-way ANOVA on social dominance showed significant effects of sex and place of residence, but not age group nor significant interactions. Men scored significantly higher than women on social dominance, providing evidence for the "invariance hypothesis". Unexpectedly, lower-class participants showed highest levels of SDO, followed by middle-class and upper-class participants. A two-way ANOVA on approval of discrimination showed significant effects of place of residence and SDO and a significant interaction. Middle-class participants showed significantly higher levels of approval of discrimination than the other two classes. SDO correlated with approval of discrimination. Unexpected effects might be due to differential levels of education among social classes and/or to social mobility. The present study is the first investigation of SDO in Mexico and shows the link between an abstract orientation towards social hierarchies and approval of class-based discrimination in everyday life.

Comparação de matizes em diferentes marcas comerciais de resina composta / Comparison of matrices in differents commercial brands of composite resins

Introdução: a seleção de cor é um processo complexo, influenciado por muitas variáveis. Esse estudo analisou comparativamente a cor de quatro resinas compostas A2 de diferentes marcar comerciais entre si e entre as resinas, e pela escala Vita Classical avaliou0se se essa diferença é captável pelo olho humano. Métodos: foram confeccionados seis corpos de prova para cada resina composta de cor A2 utilizda: Amelogen (grupo 1), Fitek Supreme (grupo 2) , Estelite (grupo 3) e Point 4 (grupo 4). Foi realizada, subsequentemente, análise por fotografia e pelo sistema CIE Lab de cada corpo de prova e da palheta da escala de cor Vita Classical. Os dados obtidos foram submetidos à análise estatística pelos métodos One Way ANOVA e de Tukey HSD. Resultados: houve diferença estatisticamente significativa entre os grupos 2 e 4 (p menor que 0,05). A resina Point 4 obteve os resultados mais próximos aos da palheta A2 da escala Vita Classical, embora seja uma variação clinicamente inaceitável. A resina Fitek Supreme apresentou os resultados mais discrepantes em relação à escala. As resinas Amelogen e Estelite não apresentaram resultados satisfatórios, mas se aproximaram mais da resina Point 4. Conclusões: ao serem analisadas resinas compostas de uma mesma cor, facilmente são encontradas discrepâncias, tanto entre diferentes amostras da mesma resina como em marcas comerciais distintas, além das divergências presentes entre a resina e a palheta de mesma cor da escala. Sendo assim, aumenta-se a dificuldades para confecção de uma restauração estética pelo profissional

Introduction: The color selection is a complex process affected by many variables. This study comparatively analyzed the color of four A2 composite resins from different commercial brands among them and between resins and the Vita Classical shade tab, assessing whether this difference is perceptible by the human eye. Methods: Six specimens were prepared for each A2 composite used: Amelogen (group 1), Filtek Supreme (group 2), Estelite (group 3) and Point 4 (group 4). By means of photographic and CIE Lab system, each specimen and of the Vita Classical's scale shade palette were analysed. The data were statistically analyzed by the One Way ANOVA and Tukey HSD methods. Results: There was a statistically signifcant difference between groups 2 and 4 (p < 0.05). Point 4 resin obtained results closer to the A2 palette from the Vita Classical scale, although in a clinically unacceptable range. Filtek Supreme resin presented the most discrepant results compared to the same scale. Amelogen and Estelite resins didn't showed satisfactory results, but it were closer to Point 4. Conclusions: Analyzing composites of the same color it can be easily found discrepancies between different samples from the same shade as well in different commercial brands, besides the differences present among the resin and the scale's palette from the same color. Therefore, it increases the diffculty of making an esthetic restoration by the professional.

Opções de preparo para laminados cerâmicos: quais, quando, como e por quê? / Choices to ceramic veneer preparations: which, when, how and why?

Os novos conceitos da Odontologia preconizam um tratamento mais conservador, que devolva estética e função. Entre as possibilidades restauradoras disponíveis, os laminados cerâmicos estão alcançando um alto nível de excelência por se encaixarem nesses novos padrões da Odontologia Moderna. Restabelecendo estética e função, as facetas indiretas de porcelana são consideradas um tratamento restaurador conservador, quando comparadas a outros tipos de restaurações, como as coroas totais...

The new concepts of Dentistry advocate a more conservative treatment that restores asthetic and functional aspects. Among the possibilities available, restorative ceramic laminates are reaching a high level of excellence that fits these new patterns of Modern Dentistry. Restoring aesthetic and function, indirect porcelain venners are considered a conservative restorative treatment when compared to other types of restorations such as full crows...

Histological modifications of the rat prostate following transection of somatic and autonomic nerves

It is known that hormones influence significantly the prostate tissue. However, we reported that mating induces an increase in androgen receptors, revealing a neural influence on the gland. These data suggested that somatic afferents (scrotal and genitofemoral nerves) and autonomic efferents (pelvic and hypogastric nerves) could regulate the structure of the prostate. Here we assessed the role of these nerves in maintaining the histology of the gland. Hence, afferent or efferent nerves of male rats were transected. Then, the ventral and dorsolateral regions of the prostate were processed for histology. Results showed that afferent transection affects prostate histology. The alveoli area decreased and increased in the ventral and dorsolateral prostate, respectively. The epithelial cell height increased in both regions. Efferent denervation produced dramatic changes in the prostate gland. The tissue lost its configuration, and the epithelium became scattered and almost vanished. Thus, afferent nerves are responsible for spinal processes pertaining to the trophic control of the prostate, activating its autonomic innervation. Hence, our data imply that innervation seems to be synergic with hormones for the healthy maintenance of the prostate. Thus, it is suggested that some prostate pathologies could be due to the failure of the autonomic neural pathways regulating the gland.

Sabe-se que os hormônios influenciam significativamente o tecido prostático. Entretanto, nós demonstramos que o acasalamento induz um aumento nos receptores androgênicos, revelando uma influência neural sobre a glândula. Esses dados sugerem que os aferentes somáticos (nervos escrotal e genito-femural) e os eferentes autonômicos (nervos pélvicos e hipo-gástricos) poderiam regular a estrutura da próstata. Neste trabalho, avaliou-se a função destes nervos na manutenção da histologia da glândula. Dessa forma, os nervos aferentes e eferentes de ratos machos foram seccionados As regiões ventral e dorsolateral da próstata foram processadas para histologia. Os resultados mostraram que a transecção aferente afeta a histologia da próstata. A área alveolar diminuiu e aumentou na próstata dorsal e dorsolateral, respectivamente. A altura da célula epitelial aumentou em ambas as regiões. A desenervação eferente produziu alterações dramáticas na glândula prostática. O tecido perdeu a sua configuração e o epitélio tornou-se difuso e quase desapareceu. Assim, os nervos aferentes são responsáveis por processos espinhais que pertencem ao controle trófico da próstata, ativando sua inervação autonômica. Dessa forma, nossos dados sugerem que a inervação parece ser sinérgica com os hormônios para a manutenção saudável da próstata. Assim, sugere-se que algumas patologias prostáticas poderiam ser ocasionadas devido a falhas nas vias neurais autonômicas que regulam esta glândula.

Efectos de la esfinterotomía biliar endoscópica sobre el vaciamiento vesicular en pacientes con coledocolitiasis

Introducción: La importancia de la motilidad vesicular y de cómo ésta puede ser modificada por procedimientos terapéuticos endoscópicos, indica el papel trascendental que tiene en la génesis de los cálculos vesiculares. Estudios previos han determinado que la esfinterotomía biliar endoscópica disminuye el volumen vesicular en ayunas e incrementa la capacidad de contracción vesicular, disminuyendo significativamente el volumen de vaciamiento vesicular, volumen residual e incrementando la fracción de eyección, posterior a la esfinterotomía endoscópica. Objetivo: Determinar el efecto de la esfinterotomía biliar endoscópica sobre la motilidad vesicular en pacientes con coledocolitiasis, hospitalizados en el Servicio de Gastroenterología del Hospital Universitario de Caracas en el período comprendido entre Mayo 2006 - Enero 2007. Métodos: estudio descriptivo, prospectivo, de una muestra seleccionada de 16 pacientes con coledocolitiasis, a quienes se les determinó volumen vesicular en ayunas, post prandial a los 18, 24 y 30 min, volumen residual y fracción de eyección; mediante ultrasonido abdominal, antes y después de la esfinterotomía endoscópica. Resultados: mediante la prueba de Wilcoxon se demostró que posterior a la esfinterotomía hubo una reducción, estadísticamente significativa (P<0.05) de los volúmenes vesiculares en ayunas, residual y postprandial a los 18, 24 min un aumento en la FE del 14.4%. con una (P= 0.014). Según sexo y edad se encontró que el sexo femenino fue el mas frecuente con 13 pacientes (81.25%), y el sexo masculino con 3 pacientes (18.75%) con una edad promedio de 41.38 años DE μ 11.4 años. Conclusiones: La esfinterotomía biliar endoscópica mejora la motilidad vesicular reflejada en una disminución del volumen en ayunas, del volumen residual y en un aumento de la fracción de eyección. Por lo que se recomienda su uso en aquellos casos donde exista indicación, además se recomienda el uso del ultrasonido abdominal como método para el estudio de la motilidad vesicular.

Introduction: The importance of gall bladder motility and of how this can be modified by endoscopic, therapeutic procedures indicates the momentous role that it has in the genesis of gall bladder stones. Previous studies have determined that endoscopic biliary sphincterotomy diminishes the gall bladder volume in fast and increases the capacity of gall bladder contraction, diminishing the emptying volume of the gall bladder significantly,as well as residual volume and increasing the ejection fraction, after endoscopic sphincterotomy. Objective: To determine the effect of endocopic sphincterotomy on gall bladder motility in patients with choledocholithiasis, hospitalized in the Gastroenterology Service of the University Hospital of Caracas in the period understood among May 2006 - January 2007. Methods: descriptive ,prospective study of a selected sample of 16 patients with choledocholithiasis to whom was determined gall bladder volume in fast, post prandial at 18, 24 and 30 min, residual volume and ejection fraction; by means of abdominal ultrasonography, before and after the endoscopic sphincterotomy. Results: by means of the test of Wilcoxon it was demonstrated that after the sphincterotomy there was a statistically significant reduction (P <0.05) of the gall bladder volumes in fast, residual and post prandial at the 18, 24 min and an increase in the EF of 14.4%. with a P = 0.014. According to sex and age it was found that the feminine sex was the most frequent with 13 patients (81.25%), and the masculine sex with 3 patients (18.75%) with an average age 41.38 years SD 11.4 years. Conclusions: Endoscopic sphincterotomy improves gall bladder motility reflected in a decrease of volume in fast, and residual volume and in an increase of the ejection fraction,being its use recommended in those cases an where indication exists. The use of the abdominal ultrasound is also recommended as a method for the study of the gall bladder motility.

Influência de um polidor resinoso na adesão de Streptococcus mutans in situ / Resinous polisher influence over in situ adhesion of Streptococcus mutans

A placa bacteriana é um biofime específico formado sobre tecidos orais, materiais restauradores, aparatos ortodônticos ou qualquer outra superfície na cavidade bucal. Entre diversos fatores a rugosidade das superfícies é de relevância crítica na qual os procedimentos de acabamento e polimento apresentam um papel vital na dentística restauradora. O objetivo deste trabalho foi de avaliar os níveis de rugosidade de quatro materiais restauradores dentais diferentes submetidos a três tipos de tratamento superficial (compressão por matriz mylar - grupo controle negativo, acabamento com pontas diamantadas de granulação fina - grupo controle positivo e aplicação de polidor resinoso BisCover™ (Bisco) depois do acabamento com as pontas diamantadas) e a influência sobre a colonização por Streptococcus mutans no biofilme inicial. Os materiais analisados foram: um cimento de ionômero de vidro convencional (Ionofil® / Voco), um cimento de ionômero de vidro modificado por resina (Vitremer™ / 3M ESPE), um compósito nano-particulado (Filtek Supreme™ / 3M ESPE) e um compósito nano-híbrido (Grandio® / Voco). A rugosidade foi medida por um instrumento de escaneamento 3-D (TalyScan 150 / Taylor Hobson) e a avaliação quantitativa de S. mutans no biofilme inicial foi realizada in vivo através da extração do biofilme dental (formado sobre discos fixados sobre moldeiras individuais usadas por um voluntário por um período de 24 horas). Um total de oito discos de cada material em cada grupo de tratamento superficial foi feito para o ensaio microbiológico e da mesma forma cinco discos foram feitos para cada situação para a mensuração da rugosidade. Resultados: análise superficial 3-D: o tratamento superficial e o tipo de material afetaram significativamente os valores de Ra e Rz (P<0.05)...

Dental plaque is a specific biofilm formed over oral tissues, restorative materials, orthodontic apparatus or any other surface in oral cavity. Among several factors, the roughness of surfaces is one of critical relevance in which finishing and polishing procedures play a vital role in restorative dentistry. The aim of this work was to evaluate the roughness levels of four different restorative dental materials submitted to three kinds of superficial treatment (compression with mylar matrix - negative control group, finishing with fine grain diamond points - positive control group and application of a resin polisher BisCover™ (Bisco) after finishing with the diamond points) and the influence on Streptococcus mutans colonization in initial biofilm. The materials analyzed were: one conventional glass ionomer cement (Ionofil® / Voco), one resin modified glass ionomer cement (Vitremer™ / 3M ESPE), one nano-filled composite resin (Filtek Supreme™ / 3M ESPE) and one nano-hybrid composite resin (Grandio® / Voco). The roughness was measured with a 3-D scanning instrument (TalyScan 150 / Taylor Hobson ) and the quantitative evaluation of S. mutans in initial biofilm was performed in vivo through dental biofilm extraction (developed over discs fixed on custom-fitted trays wore by one volunteer for a 24 hours period). A total of eight discs of each material in each superficial treatment group were made for the microbiological assay and in the same way five discs were made for each situation for the roughness measurement. Results: 3-D surface analyses: the surface treatment and the type of material significantly affected the Ra and the Rz values (P<0.05)...