Mensuração da densidade óptica de compósitos compactáveis: comparação entre sistemas digitais direto e indireto

The aim of this study was to measure the optical density of four packable composite resins with widths of 1, 2, 3 and 4 mm, by means of Digora® (direct) and DentScan DentView® (indirect) digital imaging systems, in order to compare both methods. Twenty acrylic plates, with the proposed thicknesses, were used, each one containing a sample of each resin. Each acrylic plate was radiographed three times, under a standardized technique. For the Digora® system, an optical plate was used under each resin sample, and, for the DentScan DentView® system, occlusal films were employed, totalizing 60 exposures for each system. Optical plates and films were scanned and three consecutive optical readouts were carried out, totalizing 1,440 readouts. The results were submitted to statistical analysis and revealed that the average optical density of the four resins always increased as thickness increased. Regarding the comparisons between the composite resins, in both analysis the resin with the greater optical density was SurefilTM followed by ProdigyTM Condensable, AlertTM and Solitaire®. The correlations between the results of Digora® and DentScan DentView® were significant for the different thicknesses and materials. The observed tendency is that as the values obtained with the Digora® system increase, so do the values obtained with DentScan DentView®. While thickness increased, the values of optical density in both Digora® and DentScan DentView® tended to approach each other. The Digora® system presented smaller amplitude between the results obtained in adjacent thicknesses.O objetivo deste estudo foi mensurar a densidade óptica de quatro resinas compostas compactáveis nas espessuras de 1, 2, 3 e 4 mm utilizando os sistemas de digitalização de imagens Digora® (direto) e DentScan DentView® (indireto) e compará-los entre si. Foram utilizadas 20 placas de acrílico nas espessuras propostas, cada uma contendo uma amostra de cada resina. Cada placa acrílica foi radiografada três vezes, sob técnica padronizada, usando, para o sistema Digora® uma placa óptica sob cada amostra de resina, e para o sistema DentScan DentView®, filmes oclusais, totalizando 60 exposições para cada sistema. Após, as placas ópticas e os filmes foram escaneados, e fez-se três leituras ópticas consecutivas de cada imagem, totalizando 1.440 leituras. Os resultados submetidos à análise estatística, permitiram concluir que, foi sempre crescente a média de densidade óptica das quatro resinas com o aumento da espessura. Quanto à comparação entre as resinas compostas, nas duas análises a de maior densidade óptica foi a SurefilTM, seguida em ordem decrescente, pelas resinas ProdigyTM Condensable, AlertTM e Solitaire®. As correlações entre os resultados do Digora® e DentScan DentView® foram significativas para as diferentes espessuras e materiais. A tendência observada é que à medida que os valores do Digora® aumentam, os valores do DentScan DentView® também aumentam. Com o aumento das espessuras, os valores das médias de densidade óptica das análises efetuadas com o Digora® e com o DentScan DentView® tenderam a se aproximar. O sistema Digora® apresentou, comparado com o DentScan DentView®, uma menor amplitude entre os valores das espessuras próximas

Preload and torque removal evaluation of three different abutment screws for single standing implant restorations

Several authors still consider the mechanical problems of fracture and component loosening as the main causes of failure of implant-supported restorations. The purpose of this in vitro study was to compare the preload of three types of screw for transmucosal abutment attachment used in single implant-supported prosthesis through strain gauge and removal torque measurements. Three external hex fixtures were used, and each received a transmucosal abutment (Cera One®), which was fixed to the implant with its respective screw: Group A- gold screw, Group B- titanium screw and Group C- surface-treated titanium screw (Ti-Tite®). Ten screws of each type were attached applying a 30.07±0.28 Ncm torque force and maintained in position for 5 minutes. After this, the preload values were measured using strain gauges and a measurement cell. Gold screws presented higher preload values (131.72±8.98 N), followed by surface-treated titanium screws (97.78±4.68 N) and titanium screws (37.03±5.69 N). ANOVA (

Optical density and chemical composition of microfilled and microhybrid composite resins

This study evaluated the optical density of two microfilled and two microhybrid resins, as well as the composition of these materials with regard to their optical density. Cavities prepared in 12 2-mm- or 4-mm-thick acrylic plastic plates were filled with Z250 (3M-ESPE), A110 (3M-ESPE), Charisma (Heraeus-Kulzer) and DurafillVS (Heraeus-Kulzer). The resin increments (2-mm-thick) were light-cured for 40 s. Three 0.12-s radiographic exposures were made of each #2 acrylic plastic plate. DenOptix system optical plates were used to obtain the digital images. Three readings of the composite resin surface were made in each radiograph, totalizing 216 readings. The mean of highest and lowest grey-scale values was obtained. Two specimens of each composite resin were prepared for SEM analysis of the chemical elements related to optical density, using energy dispersive x-ray analysis (EDX). The results were subjected to Shapiro-Wilk's test, ANOVA, Tukey's test at 1% level of significance and Pearson's correlation. The mean grey-scale values at 2 mm and 4 mm were: Z250 = 154.27a and 185.33w; A110 = 46.77b and 63.05y; Charisma = 163.40c and 200.46z; DurafillVS = 43.92b and 58.99x, respectively. Pearson's test did not show any positive correlation between optical density and percentage weight of optical density chemical elements. It was concluded that the microhybrid resins had higher optical density means than the microfilled resins; among the evaluated resins, Charisma had the highest optical density means

In vitro effect of plant compounds on the fungus Colletotrichum gloeosporioides Penz: isolated from passion fruit

Neste trabalho, objetivou-se avaliar o efeito de extratos e óleos essenciais de quatorze plantas medicinais e ou nativas, conhecidas popularmente no Norte de Minas Gerais, sobre a germinação de esporos e crescimento micelial do fungo Colletotrichum gloeosporioides. Foram utilizados no teste de inibição do crescimento micelial, os extratos aquosos de alecrim (Rosmarinus officinalis), erva baleeira (Cordia verbenacea), joá (Solanum sisymbriifolium), quebra-pedra (Phyllanthus corcovadensis), erva botão (Eclipta alba) e açafrão da índia (Curcuma longa) obtidos por meio do processo de infusão; óleo essencial de alecrim de vargem (Família Lamiaceae), alecrim pimenta (Lippia sidoides), alfavaca cravo (Ocimum gratissimum), lippia (Lippia citriodora), goiaba branca (Psidium guajava), capim santo (Cymbopogon citratus); óleo resina de copaíba (Copaifera langsdorffi); hidrolatos de alecrim de vargem, goiaba vermelha (Psidium guajava), lippia, capim santo, goiaba branca, alfavaca cravo; manipueira de (Manihot esculenta). Também foram testados esses mesmos hidrolatos e os óleos essenciais na germinação dos esporos do fungo. Todos os tratamentos foram realizados in vitro, cultivando-se o fungo em meio de cultura BDA acrescido de 100μL dos compostos vegetais. No teste de inibição da germinação, todos os óleos essenciais impediram a germinação do fungo. No entanto, os hidrolatos não tiveram esse efeito. No teste de crescimento micelial, os óleos essenciais de todas as plantas inibiram completamente o crescimento do fungo, exceto o óleo da goiaba branca. Os extratos aquosos, a manipueira, o óleo resina e os hidrolatos, também não foram eficientes sobre o crescimento do patógeno. Esses resultados indicam o potencial antifúngico de alguns óleos essenciais de plantas medicinais.The objective of the work was to evaluate the effect of extracts and essential oils of fourteen medicinal and or native plants popularly known in the North of Minas Gerais, on the germination of spores and the mycelial growth of Colletotrichum gloeosporioides fungus. The following were used in the mycelial growth inhibition test: the watery extracts of rosemary (Rosmarinus officinalis), Cordia verbenacea, Solanum sisymbriifolium, Phyllanthus corcovadensis, Eclipta alba, and Curcuma longa obtained through the infusion process; essential oils of "alecrim de vargem" (Lamiaceae Family), Lippia sidoides, Ocimum gratissimum, Lippia citriodora, white guava (Psidium guajava), lemongrass (Cymbopogon citratus); copaíba oil resin (Copaifera langsdorffi) as well as hydrolates of "alecrim de vargem", red guava (Psidium guajava), Lippia citriodora, lemongrass, white guava, Ocimum gratissimum; and cassava manipueira (Manihot esculenta). The same hydrolates and essential oils were also tested on the germination of the fungus spores. All the treatments were carried out in vitro, cultivating the fungus in PDA supplemented with 100μL of the vegetal compounds. In the germination inhibition test, all the essential oils prevented the germination of the fungus. However, the hydrolates did not have this effect. In the mycelial growth test, the essential oils of all of the plants completely inhibited the fungus growth, except the white guava oil. The watery extracts, the cassava manipueira, the oil resin and hydrolates were also not efficient in preventing the growth of the pathogen. These results indicate the fungitoxic potential of some essential oils of medicinal plants.CNP

Possibilidades pedagógicas para a dislexia a partir de aplicativos móveis: conhecendo o silabando e o graphogame / Pedagogical possibilities for dyslexia using mobile applications: learning about syllabus and graphogame

Esta pesquisa analisa a possibilidade de auxílio pedagógico dos aplicativos móveis Silabando e GraphoGame, no que tange à dislexia e ao processo de alfabetização da criança com tal diagnóstico. Partindo do atual contexto de pandemia, onde o ensino remoto vigora na maior parte das escolas do país, procura-se investigar se a criança com dislexia pode se beneficiar de tais tecnologias e de suas ferramentas na ampliação de suas capacidades em relação ao seu desenvolvimento cognitivo, dentro do processo de ensino-aprendizagem. Além do mais, apresenta-se os elementos principais que caracterizam a dislexia, suas especificidades e dificuldades educacionais enfrentadas por quem a tem, no intuito de estabelecer relações teóricas entre a dislexia e os aplicativos móveis apresentados. A pesquisa tem como métodos procedimentais o descritivo, utilizou-se de levantamento bibliográfico para analisar as funcionalidades dos aplicativos citados anteriormente, caracterizando-se, desse modo, como observação qualitativa. Os resultados apresentados demonstram que tanto o aplicativo Silabando, como o GraphoGame podem exercer grande influência no desenvolvimento da aquisição da leitura e da escrita, podendo ser ferramentas que agreguem positivamente à dislexia e às suas dificuldades

Spatial analysis of probable cases of dengue fever, chikungunya fever and zika virus infections in Maranhao State, Brazil

Dengue fever, chikungunya fever, and zika virus infections are increasing public health problems in the world, the last two diseases having recently emerged in Brazil. This ecological study employed spatial analysis of probable cases of dengue fever, chikungunya fever, and zika virus infections reported to the National Mandatory Reporting System (SINAN) in Maranhao State from 2015 to 2016. The software GeoDa version 1.10 was used for calculating global and local Moran indices. The global Moran index identified a significant autocorrelation of incidence rates of dengue (I=0.10; p=0.009) and zika (I=0.07; p=0.03). The study found a positive spatial correlation between dengue and the population density (I=0.31; p<0.001) and a negative correlation with the Performance Index of Unified Health System (PIUHS) by basic care coverage (I=-0.08; p=0.01). Regarding chikungunya fever, there were positive spatial correlations with the population density (I=0.06; p=0.03) and the Municipal Human Development Index (MHDI) (I=0.10; p=0.002), and a negative correlation with the Gini index (I=-0.01; p<0.001) and the PIUHS by basic care coverage (I=-0.18; p<0.001). Lastly, we found positive spatial correlations between Zika virus infections and the population density (I=0.13; p=0.005) and the MHDI (I=0.12; p<0.001), as well as a negative correlation with the Gini index (I=-0.11; p<0.001) and the PIUHS by basic care coverage (I=-0.05; p=0.03). Our results suggest that several socio-demographic factors influenced the occurrence of dengue fever, chikungunya fever, and zika virus infections in Maranhao State