Resumo Introdução A estabilidade de cor dos cimentos resinosos, sejam eles de presa dual ou fotopolimerizáveis, assim como a cor do substrato dental, são fundamentais para o sucesso estético das restaurações cerâmicas uma vez que a cerâmica apresenta alto nível de translucidez devido a sua pequena espessura. Objetivo O objetivo deste estudo in vitro foi avaliar a cor de um cimento resinoso fotopolimerizado por diferentes fontes de luz e imersos em bebidas potencialmente corantes. Material e método Foram confeccionados 42 espécimes do cimento resinoso Variolink-Esthetic (2×6mm) (n=7), sendo metade fotopolimerizado com luz LED (F1) e metade com luz Halógena (F2). Os espécimes foram mantidos em saliva artificial à 37 °C±1 °C. Após 24 horas, foram polidos com discos abrasivos e subdivididos para serem imersos 2 minutos por dia, durante 28 dias, nas diferentes soluções: S1 – Coca-Cola; S2 – Vinho Tinto; e S3 – Água destilada (controle). Foram realizadas 5 leituras de cor: T0 – inicial; T1 – 7 dias; T2 – 14 dias; T3 – 21 dias; e T4 – 28 dias; com auxílio de um espectrofotômetro (modelo SP62S). Os dados de alteração de cor (ΔE*) foram submetidos a análise estatística, ANOVA e Tukey (p≤0,05). Resultado Analisando o fator solução, S2 (5,89 (±0,02)), proporcionou maior ΔE* que S1 (3,79 (±0,02)) e este (S1), maior que S3 (1,41 (±0,02)). Analisando o fator fonte de luz, F2 (4,05 (±0,12)), proporcionou maior ΔE* que F1 (3,33 (±0,12)). E analisando o fator tempo, obteve-se que ΔE* foi gradativamente aumentando no decorrer do tempo: T1(2,36 (±0,08)); T2(3,27 (±0,08)); T3(4,06 (±0,08)); e T4(5,09 (±0,08)). Conclusão Conclui-se que o vinho tinto promoveu maior alteração de cor; a luz Halógena promoveu maior pigmentação e; quanto maior o tempo de imersão, maior alteração de cor do material.

Abstract Introduction The color stability of resin cements, whether dual-pre-cured or photopolymerizable, as well as the color of the dental substrate, are fundamental for the aesthetic success of ceramic restorations, since the ceramic presents a high level of translucency due to its small thickness. Objective The aim of this in vitro study was to evaluate the color of a resin cement light polymerized by different light sources and immersed in potentially staining beverages. Material and method Were made 42 specimens of resin cement Variolink-Esthetic (2×6mm) (n=7), being half polymerized with LED light (F1) and half with Halogen light (F2). The specimens were stored in artificial saliva at 37 °C±1 °C. After 24 hours, they were polished with abrasive discs, and divided for the purpose of being submitted to the different solutions for 2 minutes per day, for 28 days, as follows: S1 – Coca-Cola; S2 – Red Wine; and S3 – Distilled Water (Control). Five color readouts were taken: T0 – initial; T1 – 7 days; T2 – 14 days; T3 – 21 days; and T4 – 28 days; with a spectrophotometer (Model SP62S). The color change data (ΔE*) were submitted to statistical analysis, ANOVA and Tukey (p≤0.05). Result Analyzing the factor solution, S2 (5.89 (±0.02)), produced a higher ΔE* value than S1 (3.79 (±0.02)) and (S1), a higher value than S3 (1.41 (±0.02)). Analyzing the factor light source, F2 (4.05 (±0.12)), produced a higher ΔE* value than F1 (3.33 (±0.12)). When analyzing the factor time, ΔE* values were found to increase gradually over the course of time: T1(2.36 (±0.08)); T2(3.27 (±0.08)); T3(4.06 (±0.08)); and T4(5.09 (±0.08)). Conclusion It was concluded that red wine produced a greater color change; Halogen light promoted highest degree of pigmentation; and the longer the time of immersion, the greater the color change of the material.

Este estudo avaliou a influencia do ácido clorídrico na rugosidade superficial de resinas compostas submetidas a escovação. Sessenta corpos de prova medindo 2 mm de espessura x 6 mm de diâmetro foram confeccionados e utilizados como unidades experimentais. O presente estudo envolve uma análise fatorial 3x2, onde os fatores foram resina composta (n=20), com 3 níveis: resina composta microhíbrida (Z100), nanoparticulada (Filtek TM Supreme) e nanohíbrida (Ice); e desafio ácido (n=10), com 2 níveis: ausência e presença. O desafio ácido foi realizado por meio da imersão em ácido clorídrico (pH 1,2) por 4 h diárias, 1 min cada imersão, durante 7 dias. Os espécimes que não foram submetidos ao desafio ácido foram armazenados em 15 mL de saliva artificial a 37 °C. Todos os espécimes foram submetidos ao desafio abrasivo. O processo de escovação foi realizado com 200 g de peso, com velocidade de 356 rpm, totalizando 17,8 ciclos. As medidas de rugosidade superficial (Ra) foram realizadas e analisadas por meio da ANOVA e teste de Tukey (p<0,05). Os valores de rugosidade superficial foram maiores na presença (1,07±0,24)quando comparado com a ausencia do ácido hidroclorídrico (0,72±0,04). A resina microhíbrida (1,01±0,27) apresentou maior rugosidade superficial que as resinas nanoparticulada (0,68±0,09) e nanohíbrida (0,48±0,15) quando os espécimes não foram submetidos ao desafio ácido. Na presença do ácido hidroclorídrico, a resina microhíbrida (1,26±0,28) e a resina nanoparticulada (1,18±0,30) apresentou maior valor de rugosidade superficia comparado com a resina nanohíbrida (0.77±0.15). O ácido hidroclorídrico influenciou a rugosidade superficial da resina composta submetida a escovação.

The purpose of this study was to determine the influence of hydrochloric acid on surface roughness of composite resins subjected to brushing. Sixty samples measuring 2 mm thick x 6 mm diameter were prepared and used as experimental units. The study presented a 3x2 factorial design, in which the factors were composite resin (n=20), at 3 levels: microhybrid composite (Z100), nanofilled composite (FiltekTM Supreme), nanohybrid composite (Ice), and acid challenge (n=10) at 2 levels: absence and presence. Acid challenge was performed by immersion of specimens in hydrochloric acid (pH 1.2) for 1 min, 4 times per day for 7 days. The specimens not subjected to acid challenge were stored in 15 mL of artificial saliva at 37 oC. Afterwards, all specimens were submitted to abrasive challenge by a brushing cycle performed with a 200 g weight at a speed of 356 rpm, totaling 17.8 cycles. Surface roughness measurements (Ra) were performed and analyzed by ANOVA and Tukey test (p≤0.05). Surface roughness values were higher in the presence (1.07±0.24) as compared with the absence of hydrochloric acid (0.72±0.04). Surface roughness values were higher for microhybrid (1.01±0.27) compared with nanofilled (0.68 ±0.09) and nanohybrid (0.48±0.15) composites when the specimens were not subjects to acid challenge. In the presence of hydrochloric acid, microhybrid (1.26±0.28) and nanofilled (1.18±0,30) composites presents higher surface roughness values compared with nanohybrid (0.77±0.15). The hydrochloric acid affected the surface roughness of composite resin subjected to brushing.

The aim of this study was to determine the influence of mouthrinses on the surface roughness of a nanofilled composite resin after toothbrushing. One hundred nanofilled composite resin specimens were prepared and randomly distributed into two groups-brushed and non-brushed-and then assigned to five subgroups, according to the mouthrinse solutions (n = 10): Colgate Plax Fresh Mint, Oral B, Cepacol, Colgate Plax, and artificial saliva. Each sample was immersed in 20 mL of the mouthrinses for 1 minute, 5 days per week, twice a day, for a 3-week period. The control group used in the study was one in which the specimens were not subjected to brushing and remained only in artificial saliva. Toothbrushing was performed once a week for 1 minute, for 3 weeks. Surface roughness measurements (Ra) were performed after the immersion period and toothbrushing, by means of a profilometer. Data were analyzed by two-way ANOVA and Tukey's test. Analysis revealed that the association between toothbrushing and Colgate Plax Fresh Mint produced the lowest surface roughness (p < 0.05). All other groups tested (Oral B, Cepacol, Colgate Plax, artificial saliva) exhibited no statistically significant differences between surfaces, whether subjected to toothbrushing or not (p < 0.05). It was concluded that the surface roughness of the nanofilled composite resin tested can be influenced by the mouthrinse associated with toothbrushing.

The aim of this article is to present a singular and practical method to compare roentgenograms, concerning optical density and contrast. This method is specifically indicated for research related to stepwedge penetrometer and photodensitometer

El objetivo de este artículo es presentar un método singular y práctico para comparar roentgenogramas, referentes a la densidad óptica y al contraste. Este método se indica específicamente para la investigación con el penetrómetro stepwedge y el fotodensitómetro

Permlastic® is a polysulfide-based impression material widely used by dentists in Brazil. It is composed of a base paste and a catalyzer containing lead dioxide. The high toxicity of lead to humans is ground for much concern, since it can attack various systems and organs. The present study involved a quantitative analysis of the concentration of lead in the material Permlastic®. The lead was determined by plasma-induced optical emission spectrometry (Varian model Vista). The percentages of lead found in the two analyzed lots were 38.1 and 40.8%. The lead concentrations in the material under study were high, but the product’s packaging contained no information about these concentrations.

The aim of this study was to assess a bilateral comparison of the mandible density in both sex young patients with computer densitometry. Fifty panoramic radiographs were obtained from young patients with ages between 18 and 23 years old (group A = 25 female and group B = 25 male) standardized, using the same X-Ray equipment (Siemens, lOKvp, 7mA), scanned with a 282.110 pixels resolution, and transferred later to a computer and using the SIDEXIS (Sirona, USA) program to analyze the bone densitometry performance. Bilateral sites were standardized with the objective to measure the bone density. Obtained data were registered and submitted to statistical analysis. The following means and standard deviations were obtained, in pixels, for the right and the left side, respectively: group A= 154.36±36.90 e 186.12+31.41, group B= 162.07±34.94 and 180.15+30.96. These values show statistical difference between different sides and groups (p<0.05), with a higher bone density on the left side in both groups, especially in group A

El objetivo de este estudio fue realizar una comparación bilateral de la densidad de mandíbula en pacientes jóvenes de ambos sexos con computadora densitométrica ósea. Fueron obtenidas 50 radiografías panorámicas de pacientes jóvenes entre 18 y 23 años de edad (Grupo A = 25 femenino y el grupo B = 25 masculino), utilizando el mismo equipo de radiografía (Siemens, 1 OKvp, 7mA). Se escaneó con una resolución de 282,110 pixels, transfiriéndose luego a un computador para el estudio por medio del programa SIDEXIS (Sirona, USA) para analizar el desempeño densitométrico de hueso. Los sitios bilaterales fueron estandarizados con el objetivo de medir la densidad de hueso. Los datos obtenidos fueron registrados y sometidos a análisis estadístico. Las medias y los desvíos padrón fueron obtenidos en pixels, para el lado derecho y el lado izquierdo, respectivamente: Grupo A = 154,36±36,90 y 186,12±31,41, grupo B = 162,07±34,94 y 180,15±30,96. Estos valores muestran la diferencia estadística entre lados y grupos diferentes (p<0,05), con una densidad más alta de hueso en el lado izquierdo en ambos grupos, especialmente en grupo A