SUMMARY: Mini-cutting is the most common commercially used clonal propagation method in Brazil. However, several environmental interferences can impact this process, hindering the production of propagules. Mini-tunnel have been used to overcome these difficulties, allowing for an increase in the productivity of mini-stumps and the rooting of mini-cuttings. This study aimed to evaluate the effect of mini-tunnel models on the mini-stump productivity of two hybrid eucalyptus clones over two seasons. The study was conducted in the seedling nursery of a forestry company located in Alto Vale do Jequitinhonha, Minas Gerais, Brazil. Three models of the mini-tunnel were used: mini-tunnel 35 cm, 55 cm, 55 cm tubular, and without cover (control) over two seasons (cold and hot). The total and effective productivity of mini-cuttings were evaluated and the levels of chlorophyll A and B, total chlorophyll, height, leaf area, and dry matter of the mini-cuttings were determined. Together, season and use of the mini-tunnel influenced the productivity of the mini-cuttings of both clones. Use of the mini-tunnel resulted in high productivity, especially in the cold period. Mini-cuttings produced during the hot season showed greater growth, dry matter, and leaf area than those collected during the cold season. The use of mini-tunnels is an effective method to increase the productivity of clonal eucalyptus mini-gardens, as shown here by its overall positive influence on mini-cuttings of both genotypes.

RESUMEN: El miniestaca es el método de propagación clonal más utilizado comercialmente en Brasil. Sin embargo, este proceso sufre varias interferencias ambientales que pueden dificultar la producción de propágulos. Los mini túneles se han utilizado para superar estas dificultades, permitiendo también un aumento de la productividad de las minicepas y el enraizamiento de las miniestacas. Este estudio tuvo como objetivo evaluar el efecto de los modelos de mini túneles sobre la productividad de minicepas de dos clones híbridos de eucalipto, en dos temporadas. El estudio se realizó en el vivero de plántulas de una empresa forestal ubicada en Alto Vale do Jequitinhonha, Minas Gerais, Brasil. Se utilizaron tres modelos de mini túneles: mini túnel de 35 cm, 55 cm, tubular de 55 cm y sin cobertura (control), en dos temporadas (frío y calor). Se evaluó la productividad total y efectiva de miniestacas y se determinaron los niveles de clorofila A y B, clorofila total, altura, área foliar y masa seca de las miniestacas. La temporada y el uso del mini túnel, en conjunto, influyeron en la productividad de las miniestacas de ambos clones. El uso del mini túnel resultó en una alta productividad, especialmente en el período frío. Las miniestacas producidos en la estación cálida mostraron mayor crecimiento, materia seca y área foliar, que los recolectados en la estación fría. El uso del mini túnel es un método eficaz para aumentar la productividad de los minihuertos clonales de eucalipto, como lo demuestra aquí su influencia positiva general sobre las miniestacas de ambos genotipos.

Abstract This in vitro study aimed to evaluate the effects of different luting protocols on the thickness of luting interface of ceramic laminate veneers. Thirty-six lithium disilicate blocks (7 × 8 × 0.6 mm) were cemented onto bovine enamel. They were divided into 6 groups based on the luting protocol (no previous photoactivation of the dental adhesive; previous activation of the dental adhesive only on enamel surface; and previous photoactivation of the dental adhesive on both the enamel surface and inner surface of ceramic laminate) and the luting materials used (Single Bond Universal/RelyX Veneer and Tetric N Bond/Variolink Veneer). The luting interface thickness of ceramic laminate veneers was evaluated using a laser scanning confocal microscope (n = 6). The luting interface measurements were analyzed using 2-way ANOVA and the Tukey least significant difference test (α = 0.05). Prior activation of the adhesive on the dental enamel and inside the ceramic laminate exhibited higher luting interface thickness than that with no prior photoactivation of both luting materials (p < 0.05). Specimens cemented with Tetric N Bond/Variolink Veneer, submitted for prior photoactivation of the adhesive on the dental enamel and on both dental enamel and inner surface of ceramic, exhibited lower luting interface thickness than those luted with Single Bond Universal/RelyX Veneer (p < 0.05). The prior photoactivation of dental adhesives influenced the thickness of luting interface in laminate restorations. Tetric N Bond/Variolink Veneer yielded more satisfactory results than Single Bond Universal/RelyX Veneer when the adhesive was light activated.

Abstract Objective The aim of this study was to compare two in vitro erosion protocols, in which one simulates in vivo conditions experienced by patients with gastroesophageal disorders or bulimia (HCl-pepsin protocol), and the other simulates the diet of an individual who consumes a high volume of erosive beverages (citric acid protocol). In addition, the mechanical properties and surface gloss of eroded human dentin were compared with those of sound human dentin. Materials and Methods Blocks of cervical dentin were used: sound human dentin (n=10), human dentin with erosive lesions (n=10), and bovine dentin (n=30). Twenty bovine blocks were subjected to either of two erosion protocols (n=10/protocol). In the first protocol, samples were demineralized using HCl-pepsin solution, then treated with trypsin solution. In the second protocol, samples were demineralized with 2% citric acid. Toothbrushing was performed in both protocols using a toothbrushing machine (15 s with a 150 g load). Ten bovine dentin blocks were not subjected to any erosive treatment. All samples of bovine and human dentin were analyzed to obtain Martens hardness values (MH), elastic modulus (Eit*) and surface gloss. One-way ANOVA and Tukey's test were performed to analyze the data (α=0.05). Results Sound human and eroded human dentin groups showed similar MH and Eit* values (p>0.05); however, sound human dentin showed a higher surface gloss value when compared to eroded human dentin (p<0.05). Sound bovine dentin and HCl-pepsin-treated bovine dentin treatments resulted in similar values for both MH and Eit* (p>0.05), but HCl-pepsin-treated bovine dentin and citric acid-treated bovine dentin resulted in lower surface gloss than sound bovine dentin (p<0.05). Conclusions The HCl-pepsin protocol modified bovine dentin properties that could be similar to those that occur on human dentin surfaces with erosive lesions.

RESUMEN El propósito de este trabajo fue analizar en prótesis totales maxilares la influencia del tamaño de los arcos en el movimiento de dientes artificiales cuando los mismos   se someten a las inclusiones con  barrera de yeso tipo IV (especial), polimerizado en microondas y medidas gráficamente por computadora. Veinte y una réplicas de prótesis que se habían construido previamente, fueran divididos en tres grupos: grupo 1, constituido de 7 prótesis maxilares del tamaño pequeño; grupo 2, constituido de 7 prótesis de tamaño medio y, grupo 3, de gran tamaño. Las prótesis habían sido medidas en puntos demarcados previamente en los dientes, con un programa de computación gráfica, después del encerado y después de la polimerización y demuflado. La diferencia entre la medida, en las dos etapas, demostró la ocurrencia de pequeñas alteraciones. Fue concluido, del punto de vista estadístico, que no ha tenido diferencias significativas en las alteraciones de la posición de dientes, en los tres tamaños de modelos estudiados.

ABSTRACT The purpose of this study was to evaluate the influence of maxillary arch size on the artificial teeth movement in complete dentures. The maxillary dentures were processed with a barrier-type IV gypsum molding technique, and polymerized by microwave energy. Twenty one dentures were fabricated and equally divided into 3 groups, according to maxillary residual ridge size: G1) small; G2) medium and G3) large size. Reference points were made on the incisal edges of the central incisors and the supporting cusps of the premolar and second molar teeth. Linear distances among reference points, in a horizontal plane, were measured with a computer program (Auto cad 2000) before and after processing denture. Although there were differences between measurements, indicating some movement degree among artificial teeth, the results showed no statistical significantly differences among three groups studied. It was concluded that the maxillary arch size has not influence on the artificial teeth position

The purpose of this study was to evaluate the presence of superficial bubbles and dimensional changes of three types of irreversible hydrocolloids smoothened with a moist finger and not smoothened. A master die was made with acrylic resin, representing an edentulous maxillary palate that was modified in order to provide a flat surface. Five pins were inserted in the alveolar crest at predetermined areas. The study was divided in 6 groups in agreement with the molding technique and the hydrocolloid material (Jeltrate, Jeltrate Plus and Hidrogum). These consisted of 10 impressions for each group. The palate region of the molds was assessed with a microscope (50x) to allow bubble scoring. The mold was immediately poured with type IV dental stone. The casts were scanned and digitalized. The distances between pins were measured employing AutoCAD 2000. The data was submitted to ANOVA and Tukey´s test with significance level of 5%. There were no significant differences between cast accuracy obtained from either impression technique regardless of the alginate tested. From the results obtained it was concluded that the presence of bubbles was significantly higher (p < 0.05) in the groups that water rinsing with was not performed; the alginate «Jeltrate» showed a larger discrepancy between both techniques (with and without moist finger smoothening).

El objetivo del estudio fue evaluar la presencia de burbujas superficiales y la alteración dimensional en los modelos obtenidos de impresiones de alginato, con y sin alisamiento con el dedo humedecido en agua. Se hizo una matriz en resina acrílica del maxilar desdentado cuyo paladar se modificó para que presentara una superficie llana y lisa y se insertaron 5 pernos metálicos en la cresta del reborde en lugares predeterminados. El estudio se dividió en 6 grupos de acuerdo con la técnica de impresión y del material usado (Jeltrate, Jeltrate plus e Hidrogum), con un total de 10 modelos para cada grupo. El paladar de los modelos se valoró con lupa (50 aumentos) lo que permitió la estimación de las burbujas. La lectura de los modelos se hizo por digitalización de los modelos, midiendo la distancia entre los pernos con el software AutoCAD 2000. Los datos según el análisis de la varianza (ANOVA) y el test de Tukey (5%) indicaron una reducción significativa en el porcentaje de burbujas cuando se hacia el alisamiento. Los modelos donde se hizo el alisamiento presentaran alteraciones sin diferencias estadísticamente significativas respecto a los grupos donde no se hizo el alisamiento. El análisis de los resultados permitió concluir que el alisamiento del alginato con el dedo humedecido no afectó la precisión de los modelos del yeso en ningunos de los alginatos probados. El alisado dio lugar a una reducción significativa en el número de burbujas superficiales.