Mineral loss and color change of enamel after bleaching and staining solutions combination

Pigments of food and beverages could affect dental bleaching efficacy. The aim of this investigation was to evaluate color change and mineral loss of tooth enamel as well as the influence of staining solutions normally used by adolescent patients undergoing home bleaching. Initial hardness and baseline color were measured on enamel blocks. Specimens were divided into five groups (n = 5): G1 (control) specimens were kept in artificial saliva throughout the experiment (3 weeks); G2 enamel was exposed to 10% carbamide peroxide for 6 h daily, and after this period, the teeth were cleaned and stored in artificial saliva until the next bleaching session; and G3, G4, and G5 received the same treatments as G2, but after bleaching, they were stored for 1 h in cola soft drink, melted chocolate, or red wine, respectively. Mineral loss was obtained by the percentage of hardness reduction, and color change was determined by the difference between the data obtained before and after treatments. Data were subjected to analysis of variance and Fisher's test (a = 0.05). G3 and G5 showed higher mineral loss (92.96 +/- 5.50 and 94.46 +/- 1.00, respectively) compared to the other groups (p = 0.05). G5 showed high-color change (9.34 +/- 2.90), whereas G1 presented lower color change (2.22 +/- 0.44) (p = 0.05). Acidic drinks cause mineral loss of the enamel, which could modify the surface and reduce staining resistance after bleaching. (C) 2013 Society of Photo-Optical Instrumentation Engineers (SPIE)

Sensory profile and acceptability of traditional and double-distilled cachaca aged in oak casks

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Extratos de moringa no tratamento do caldo de cana e reflexos sobre a fermentação alcoólica

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

A cachaça nos dois lados do Atlântico: produção comércio e proibição

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of Beverages and Mouthwashes on the Hardness of Polymers Used in Intraoral Prostheses

PurposeThe mechanical properties of acrylic resins used in intraoral prostheses may be altered by frequent exposure to liquids such as beverages and mouthwashes. This study aimed to evaluate the effect of thermocycling and liquid immersion on the hardness of four brands of acrylic resins commonly used in removable prostheses (Onda Cryl, QC-20, Classico, Lucitone).Materials and MethodsFor each brand of resin, seven specimens were immersed in each of six solutions (coffee, cola, red wine, Plax-Colgate, Listerine [LI], Oral B), and seven more were placed in artificial saliva (control). The hardness was tested using a microhardness tester before and after 5000 thermocycles and after 1, 3, 24, 48, and 96 hours of immersion. The results were analyzed using three-way repeated-measures ANOVA and Tukey's test (p < 0.05).ResultsThe hardness of the resins decreased following thermocycling and immersion in the solutions. Specimens immersed in cola and wine exhibited significant decreases in hardness after immersion for 96 hours, although the greatest significant decrease in hardness occurred in specimens immersed in LI. However, according to American Dental Association specification 12, the Knoop hardness of acrylic resins for intraoral prostheses should not be below 15. Thus, the median values of superficial hardness observed in most of the acrylic resins in this study are considered clinically acceptable.ConclusionsThe microhardness of polymers used for intraoral prostheses decreases following thermocycling. Among specimens immersed in beverages, those immersed in cola or wine experienced the greatest decrease in microhardness. Immersion of acrylic resins in LI significantly decreased the microhardness in relation to the initial value. Among the resins assessed, QC-20 exhibited the lowest initial hardness.

Produção de hidrolisado enzimático de farinha de batata-doce para fermentação etanólica

Recently there is a great quest of producing alcohol from starchy resources, replacing the sugar cane. The most common starchy sources are cassava, maize and sweet potatoes and a lot of research are been realized with excellent results. In this work it was evaluated the influence of the concentration of dry matter on the enzymatic hydrolysis process of starch from sweet potato for ethanol production. Through the sweet potato was produced a flour using a low-cost method and easy operation equipments. The sweet potato flour was characterized physical and chemically and from these results was prepared the treatments for enzymatic hydrolysis. The experimental design considered as independent variable the dry matter concentration of the sweet potato flour in 3 levels; 10, 15 and 20% in the formulation of suspensions. The other variables were keeping constant being: temperature in the 1° hydrolysis step of 90°C and time of 2 hours; temperature in the 2° saccharification step of 60°C and time of 17 hours. The hydrolysates obtained at the three assays were transferred to six liter enlerynmeyer and inoculated with a biologic catalyst, Saccharomyces, dehydrated yeasts of Saccharomyces cerevisiae CAT 1, at a rate of 5% in weight. The flasks were placed in a shaker type orbital with controlled temperature of 30°C during a time of 15 hours. The initial reducer sugars concentration and respective ethanol concentrations in wine were: 11.2% glucose and 2.16% ethanol in the suspension with 10% of dry matter; 13.5% glucose and 4.39% ethanol with 15% and 17.5% glucose and 6.03% ethanol in suspension with 20% of dry matter. ix The results showed that the higher percentage of dry matter carried out to higher sugar yield in hydrolyzed. It was possible observed that products quality improved with a higher concentration of dry matter

Comunidade de formigas (Hymenoptera: formicidae) em cultivo de videiras no município de São Roque - São Paulo

The cultivation of grapes is one of the most traditional cultures and the world's oldest one. In Brazil, cultivars occupy an area of approximately 90 thousand hectares, covering the south, southeast and northeast, in latitudes ranging from 30 º 56 '15''S up to 5 º 11' 15''S. The culture of the vine may be the target of the attack of some diseases and pests, and currently the main concern for growers is the subterranean mealybug, Eurhizococcus brasiliensis (Hemiptera: Margarodidae), known as pearl-ground. This arthropod infests the roots causing a progressive languish of the vine, even causes its death. In southern Brazil it is known that some species of ants can disperse pearl-ground for short distances, however, there is no information about that in the State of Sao Paulo. Thus, it is extremely important to perform studies with this focus on wine regions in this State. Therefore, this study aimed to identify the species of underground ant community in different grape varieties found in vineyards in the town of São Roque – SP, Brazil. With that purpose, samples were collected within one year. We used underground pitfalls spread across twelve points. In each of the points were placed two traps, one containing honey and the other containing sardine as attractive. The results revealed the presence of three morphospecies of ants in Niágara Rosada and four in other grape varieties, there was no significant difference in the species richness among the cultivars (Kruskal-Wallis - 0.33, p = 0.5). In both trials, the most frequent species was Brachymyrmex sp.4, suggesting that there is no dominance of distinct species of Niágara Rosada and the other grape varieties. There was no dissimilarity in species richness of the ones visiting honey or sardines (Kruskal-Wallis - 0.08, p = 0.7) and the analysis of variance indicated a great similarity in species richness between the rainy and dry seasons (Kruskal-Wallis - 0.09, p = 0.7)

Quantificação de carbamato de etila em vinhos

The ethyl carbamate is a compound present in most foods yeast-distillates; due to its carcinogenic potential, national legislation has established a limit of 0.150 µg / mL for spirits, so the values above the same, pose a threat to both public health as well for the economic sector by preventing the export of these products. The aim of this work is to provide the optimization of an analytical method employing the technique of gas chromatography equipped with flame ionization detector (FID) to determine the concentration levels of ethyl carbamate in some samples of wine. The use of ethyl acetate as solvent employed in the extraction, the ethyl carbamate present in wine samples proved to be suitable, where Recoveries were between 97.6 to 103.3% (m / m), with a standard deviation for between 0.56 to 3.50%. The concentrations of ethyl carbamate in particular wine samples vary between 3.22 µg / ml and 3.80 µg / mL, with a mean of 3.48 µg / mL. These valuesare all above the limit set by law. Thus, the results indicate the need for changes in the process of wine production, in order to control the levels of the substance

Caracterização físico-química e sensorial de vinhos brancos da região noroeste de São Paulo

Brazilian wines are appreciated by consumers for having fruity odor and taste which are typical from Vitis labrusca cultivars. The rusticity of these cultivars, the winemaking and the physicochemical properties are some of the key factors to obtain a quality beverage. In this context, the aim of this article was to analyze the quality of three white wines from wineries located in northwest region of São Paulo state by determining physicochemical properties and sensory profile. Data were analyzed by statistical tests and by Principal Component Analysis (PCA). It was possible to observe statistical differences (P<0,05) in most physicochemical properties. Furthermore, the PCA showed that the attributes body and color significantly explained the variance of the first and second component, respectively, higlighting the Vitis vinifera wine. Thus the connection between the physicochemical and sensory properties of white wines was important for characterization of these beverages produced in the northwest of São Paulo.

Porta-enxertos na produção e nas características físico-químicas da uva e do vinho de diferentes cultivares em Jundiaí, SP

Pós-graduação em Agronomia (Horticultura) - FCA

Influência do desponte de panículas de sorgo sacarino sobre a qualidade da matéria-prima e produção de bioetanol

Pós-graduação em Microbiologia Agropecuária - FCAV

Efeito da escovação dentária no manchamento de braquetes estéticos cerâmicos

Objective: this study aimed to analyze the in vitro effect of brushing on the color stability of ceramic brackets immersed in dye solutions. Materials and Methods: seven ceramic brackets of four commercial brands were tested: two monocrystalline and two polycrystalline. The parameters of color were obtained by spectrophotometer before and after 21 days of immersion of the brackets in coffee, red wine, Coca-Cola, black tea and artificial saliva. Another group of brackets of each brand were also immersed in the same solutions and for an equal time to the previous group, but with intervals of daily brushing performed by a toothbrushing machine (Mavtec). The data were evaluated by analysis of variance, multiple comparison tests for means and Student's t-test. Results: the mean color change of the brackets without brushing ranged from 0.46 to 7.61, while in the group with brushing these means ranged from 0.36 to 2.50. The staining still remained noticeable (change of color greater than 3.7) for all brackets when immersed in black tea. Conclusion: daily brushing helped significantly in the color stability of ceramic brackets, maintaining the color change to levels considered not visible to the human eye, except for the solution of black tea in which the staining remained relevant.

Effect of staining agents on color change of composites

Composite resins are materials that can present color changing when exposed to pigments. Objective: The aim of this study was to evaluate, in vitro, the color changing of composites after immersion in different substances for different periods. Material and methods: Two microhybrid composite resins: Charisma (Heraeus – Kulzer) and Opallis (FGM) were used. Red wine and acai pulp were also used as immersion medium. For this study, 32 specimens with 10 mm of diameter and 2 mm of thickness were used, divided into 4 groups: Group 1 – Opallis composite immersed in red wine solution; Group 2 – Opallis composite immersed in acai berry pulp solution; Group 3 – Charisma composite immersed in red wine solution; Group 4 – Charisma composite immersed in acai berry pulp solution. The specimens were evaluated in the following time periods: T0 – baseline, T1 – 24 hours, T2 – 48 hours, T3 – 72 hours and T4 – 96 hours. For the assessment of staining, a spectrophotometer for colorimetry was used (Color Guide 45 / 0, PCB 6807 BYK-Gardner Gerestsried GmBH, Germany), and the values obtained were transferred to a computer and recorded according to CIELAB system. Results: The data were evaluated using Kruskal- Wallis non-parametric tests with the following mean values for the immersion periods of 24, 48, 72 and 96 hours, respectively: G1 – 7.35, 7.84, 9.04,10.48; G2 – 2.92, 4.15, 4.30, 4.64; G3 – 3.14, 7.35, 8.13, 8.43, G4 – 4.49, 5.99, 6.92, 6.76. Conclusion: Red wine showed a higher tendency toward altering the composite color than acai berry pulp. In addition, no significant difference was found concerning to the behavior of the two composite resins. Concerning to the immersion time periods, significant differences were only observed among the groups in the 24 hour time period.

In vitro study of staining agents effects on optical properties of esthetic restorative materials

The authors have studied the effect of four staining agents on the optical properties of esthetic restorative materials through translucency tests. Two commercial brands of composite resins were used: Point 4 (Kerr) and Charisma (Heraeus-Kulzer). The liquids tested were: wine, cola, chlorhexidine solution and nicotine solution. The translucency was measured at different periods of time: P0 – before immersion (baseline), P1 - 1 h after immersion, P2 - 2 h after immersion and successively, P3 – 24 h after immersion up to a period of 7 weeks. ANOVA statistical analysis was applied to the data (p < 0.05). The results lead to the following conclusions: (1) Composite resins submitted to the tested immersion mediums were stained, (2) the lower percentage of translucency was observed for nicotine containing solution, (3) The percentage of translucency decreased with the period of immersion.

Colour stability of acrylic resin denture teeth after immersion in different beverages

The colour stability of acrylic resin denture teeth in beverages was investigated. A spectrophotometer measured the colour (CIE-L*a*b* system) of all specimens after storage in distilled water for 24 h at 37°C (T0). Specimens were then immersed in various beverages. After 15 days (T1) and 30 days (T2), for each material, the mean ∆E values were calculated and compared by two-way ANOVA and Tukey intervals (α=0.05). In the ∆T0T1 period, specimens stored in red wine were significantly discoloured, compared to distilled water (P=0.003). There was no difference between immersion solutions in ∆ET0T2 (P=0.772) and in ∆ET1T2 (P=0.058), and no difference between materials in all immersion periods.