Qualidade físico-química e de fritura de tubérculos de cultivares de batata na safra de inverno

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The Styracaceae

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

Laboratory evaluation of Amazon forest biomass burning emissions

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

THE EFFECT of IMMEDIATE DENTIN SEALING on THE MARGINAL ADAPTATION and BOND STRENGTHS of TOTAL-ETCH and SELF-ETCH ADHESIVES

Statement of problem. Sealing ability and bond strengths of total-etch and self-etch dentin adhesives used for immediate dentin sealing have not been assessed and established.Purpose. The purpose of this study was to determine the effectiveness of immediate dentin sealing (IDS) using total-etch or self-etch dentin adhesives on microleakage and microtensile bond strength.Material and methods. Twenty recently extracted molars were selected, and standard MOD inlay preparations were made with the gingival margins located below the cemento-enamel unction. The teeth were assigned to 4 experimental groups (n=5) according to the indirect composite restoration cementation technique used: (1) immediate dentin sealing with Adper Single Bond (TEBI); (2) conventional adhesive cementation technique using Adper Single Bond (TEAI); (3) immediate dentin sealing using Adper Prompt L-Pop (SEBI); or (4) conventional adhesive cementation technique using Adper Prompt L-Pop (SEAI). The restored teeth were thermal cycled 1,000 times between 5 degrees and 55 degrees C and then immersed in 50% ammoniacal silver nitrate. Three specimens per restoration were evaluated for microleakage, according to predefined scores, and submitted to Friedman's test (alpha-.05). The specimens were then sectioned to obtain 0.8 +/- 0.2-mm-thick sticks (with n ranging from 32 to 57 specimens) and submitted to microtensile bond strength (mu TBS) testing. The obtained data were submitted to 2-way ANOVA test (alpha=.05).Results. None of the experimental groups demonstrated complete elimination of marginal microleakage. There were significant differences in microleakage of the tested adhesives (P>.001). IDS microleakage scores were similar to those obtained using the conventional cementation technique (CCT) for both adhesives. The highest mean bond strengths were obtained with TEBI (51.1 MPa), whereas SEAI showed the lowest mean bond strengths (1.7 MPa). IDS resulted in significantly higher bond strengths than CCT (P<.001).Conclusions. Total-etch and self-etch adhesives have a significant effect on IDS. IDS resulted in high bond strengths for both adhesives; however, the microleakage was similar to that obtained with CCT (J Prosthet Dent 2009;102:1-9)

Comparative scanning electron microscopic study of the effect of different dental conditioners on dentin micromorphology

This study evaluated comparatively by scanning electron microscopy (SEM) the effect of different dental conditioners on dentin micromorphology, when used according to the same protocol. Forty dentin sticks were obtained from 20 caries-free third human molars and were assigned to 4 groups corresponding to 3 conditioners (phosphoric acid 37%, Clearfil SE Bond and iBond) and an untreated control group. After application of the conditioners, the specimens were immersed in 50% ethanol solution during 10 s, chemically fixed and dehydrated to prepare them to SEM analysis. In the control group, dentin surface was completely covered by smear layer and all dentinal tubules were occluded. In the phosphoric acid-etched group, dentin surface was completely clean and presented exposed dentinal tubule openings; this was the only group in which the tubules exhibited the funnel-shaped aspect. In the groups conditioned with Clearfil SE Bond primer and iBond, which are less acidic than phosphoric acid, tubule openings were occluded or partially occluded, though smear layer removal was observed. SE Bond was more efficient in removing the smear layer than iBond. In the Clearfil SE Bond group, the cuff-like aspect of peritubular dentin was more evident. It may be concluded all tested conditioners were able to change dentin morphology. However, it cannot be stated that the agent aggressiveness was the only cause of the micromorphological alterations because a single morphological pattern was not established for each group, but rather an association of different aspects, according to the aggressiveness of the tested conditioner.

Does Adhesive Resin Application Contribute to Resin Bond Durability on Etched and Silanized Feldspathic Ceramic?

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of dental surface treatment with Nd:YAG and Er:YAG lasers on bond strength of resin composite to recently bleached enamel

The aim of this work is to evaluate the effect of surface treatment with Er:YAG and Nd:YAG lasers on resin composite bond strength to recently bleached enamel. In this study, 120 bovine incisors were distributed into two groups: group C: without bleaching treatment; group B: bleached with 35% hydrogen peroxide. Each group was divided into three subgroups: subgroup N: without laser treatment; subgroup Nd: irradiation with Nd:YAG laser; subgroup Er: irradiation with Er:YAG laser. The adhesive system (Adper Single Bond 2) was then applied and composite buildups were constructed with Filtek Supreme composite. The teeth were sectioned to obtain enamel-resin sticks (1 x 1 mm) and submitted to microtensile bond testing. The data were statistically analyzed by the ANOVA and Tukey tests. The bond strength values in the bleached control group (5.57 MPa) presented a significant difference in comparison to the group bleached and irradiated with Er:YAG laser (13.18 MPa) or Nd:YAG (25.67 MPa). The non-bleached control group presented mean values of 30.92 MPa, with statistical difference of all the others groups. The use of Nd:YAG and Er:YAG lasers on bleached specimens was able to improve the bond strengths of them.

Microtensile bond strengths and scanning electron microscopic evaluation of self-adhesive and self-etch resin cements to intact and etched enamel

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

Evaluation of Bond Strength of Self-adhesive Cements to Dentin With or Without Application of Adhesive Systems

Purpose: To evaluate the bond strength of indirect restorations to dentin using self-adhesive cements with and without the application of adhesive systems.Material and Methods: Seventy-two bovine incisors were used, in which the buccal surfaces were ground down to expose an area of dentin measuring a minimum of 4 x 4 mm. The indirect resin composite Resilab was used to make 72 blocks, which were cemented onto the dentin surface of the teeth and divided into 4 groups (n = 18): group 1: self-adhesive resin cement BiFix SE, applied according to manufacturer's recommendations; group 2: self-adhesive resin cement RelyX Unicem, used according to manufacturer's recommendations; group 3: etch-and-rinse Solobond M adhesive system + BiFix SE; group 4: etch-and-rinse Single Bond 2 adhesive system + RelyX Unicem. The specimens were sectioned into sticks and subjected to microtensile testing in a universal testing machine (EMIC DL-200MF). Data were subjected to one-way ANOVA and Tukey's test (alpha = 5%).Results: The mean values (+/- standard deviation) obtained for the groups were: group 1: 15.28 (+/- 8.17)(a), group 2: 14.60 (+/- 5.21)(a), group 3: 39.20 (+/- 9.98)(c), group 4: 27.59 (+/- 6.57)(b). Different letters indicate significant differences (ANOVA; p = 0.0000).Conclusion: The application of adhesive systems before self-adhesive cements significantly increased the bond strength to dentin. In group 2, RelyX Unicem associated with the adhesive system Single Bond 2 showed significantly lower mean tensile bond strengths than group 3 (BiFix SE associated with the etch-and-rinse Solobond M adhesive system).

Effects of Surface Hydration State and Application Method on the Bond Strength of Self-etching Adhesives to Cut Enamel

Purpose: To evaluate the effect of surface hydration state and application method on the microtensile bond strength of one-step self-etching adhesives systems to cut enamel.Materials and Methods: One hundred ninety-five bovine teeth were used. The enamel on the buccal side was flattened with 600-grit SiC paper. For the control group, 15 teeth received Adper Single Bond 2, applied according to manufacturer's recommendations. The other specimens were divided into three groups according to the adhesive system used: Futura Bond M (FM; Voco), Clearfil S-3 Bond (CS; Kuraray), and Optibond All in One (OA; Kerr). For each group, two hydration states were tested: D: blown dry with air; W: the excess of water was removed with absorbent paper. Two application methods were tested: P (passive): the adhesive was simply left on the surface; A (active): the adhesive was rubbed with an applicator point. A coat of Grandio composite resin (Voco) was applied on the surface. The teeth were sectioned to obtain enamel-resin sticks (1 x 1 mm), which underwent microtensile bond testing. The data in MPa were submitted to a three-way ANOVA and Tukey's test (alpha = 5%).Results: The ANOVA showed significant differences for application method and the type of adhesive, but not for hydration state. For the application method, the results of Tukey's test were: P: 31.46 (+/-7.09)a; A: 34.04 (+/-7.19)b. For the type of adhesive, the results were: OA: 31.29 (+/-7.05)a; CS: 32.28 (+/-7.14)a; FM: 34.68 (+/-7.17)b; different lower-case letters indicate statistically significant differences.Conclusion: Active application improved the bond strength to cut enamel. The adhesive Futurabond M showed the highest bond strength to cut enamel.

Bond strength and morphology of resin materials applied to the occlusal surface of primary molars

International Journal of Paediatric Dentistry 2012; 22: 435441 Background. Hydrophilic adhesives may be used as pit and fissure sealants (sealants), but there is concern about the ability of self-etching adhesives to bond sealants to enamel. Aim. To study the bond strength (BS) and morphology of adhesive systems used as sealants. Design. OptiBond FL, OptiBond All-in-One, combined OptiBond All-in-One + OptiBond FL adhesive, and Fluroshield were applied to the occlusal surfaces of 16 primary molars (n = 4). Teeth were stored in distilled water (24 h at 37 degrees C) and sectioned through the interface to obtain sticks (0.8 mm2) tested under a tensile load (0.5 mm/min). Failure modes were observed. Data were analysed by ANOVA and Tukeys tests (a = 5%). The morphology of 12 primary molars was examined in terms of the etching pattern and resin reproduction. Results. Differences in the BS were found (P = 0.001), with OptiBond FL showing the highest (36.84 +/- 5.7 MPa), Fluroshield (24.26 +/- 2.13 MPa) and OptiBond All-in-One (17.12 +/- 4.97 MPa) similar, and OptiBond All-in-One + OptiBond FL adhesive the lowest (9.8 +/- 2.94 MPA). OptiBond FL showed the best results in terms of morphology. Conclusion. Under the conditions of this study, OptiBond FL was the best material to be used for sealing.

Os convivas da morte no banquete das almas: presença de eguns em um conto de João Antônio

A literatura escrita tem sido um espaço privilegiado para a representação e, consequentemente, para o registro e divulgação dos valores e costumes de variados grupos e segmentos sociais. No conto analisado neste ensaio – Eguns –, o escritor paulistano João Antônio (1937-1996) traz um narrador que descreve com detalhes uma rara festa religiosa ocorrida na Bahia, destinada ao culto dos ancestrais. Contemplativo e respeitoso, limita-se a contar o que a tradição religiosa permite. O contato com a alteridade ganha foros de rito iniciático e a experiência – em sentido forte – é transferida ao leitor.

Nesting behavior of the Picazuro Pigeon, Columba Picazuro (Columbidae, aves)

A pomba-asa-branca nidifica em todos os meses do ano no sudeste do Brasil. O material do ninho é quebrado dos ramos secos no tôpo de árvores ou pêgo no chão e levado para construir um ninho frágil e transparente onde será depositado um ovo. Fêmea e macho alternam-se na incubação e na criação do filhote e eles não sujam as bordas dos ninhos com fezes.

Tetanorhynchus leonardosi (Mello-Leitão) (Orthoptera: Proscopiidae), nova praga em eucaliptos

We report for the first time the attack of the walking stick Tetanorhynchus leonardosi (Mello-Leitão) (Orthoptera: Proscopiidae) on young eucalyptus, Eucalyptus urophylla, in Brazil. The upper third of the trees was attacked (apical meristems and new leaves). During the hottest hours of the day the insects were found sheltered between leaves on the median third of the plants, and feeding when temperatures were milder. The attack was heterogeneous in the stand, being more concentrated when it was neighbouring an area of native 'Cerrado' vegetation. Mean defoliation was 5.8%, with an average of 5.2% of plants with apical meristems cut by the walking sticks. An application of Methyl Parathion was not effective against the pest. Apparently plants older than 6 months were less attacked by the insects, that preferred 3-month old trees. The reduction of native vegetation may explain the dispersion of T. leonardosi from its native host plants to the exotic eucalyptus.

Polymerization shrinkage: effects of boundary conditions and filling technique of resin composite restorations

Objective: To evaluate the linear polymerization shrinkage (LPS) and the effect of polymerization shrinkage of a resin composite and resin-dentin bond strength under different boundary conditions and filling techniques.Methods: Two cavities (4 x 4 x 2 MM) were prepared in bovine incisors (n = 30). The teeth were divided into three groups, according to boundary conditions: In group TE, the total-etch technique was used. In group EE, only enamel was conditioned, and in group NE, none of the watts of the cavities were conditioned. A two-step adhesive system was applied to all cavities. The resin composite was inserted in one (B) or three increments (1), and tight-cured with 600 mW/cm(2) (80 s). The LPS (%) was measured in the top-bottom direction, by placing a probe in contact with resin composite during curing. Enamel and total mean gap widths were measured (400 x) in three slices obtained after sectioning the restorations. Then, the slices were sectioned again, either to obtain sticks from the adhesive interface from the bottom of the cavity or to obtain resin composite sticks (0.8 mm(2)) to be tested for tensile strength (Kratos machine, 0.5 mm/min). The data was subjected to a two-way repeated measures ANOVA and Tukey's test for comparison of the means (alpha = 0.05).Results: the highest percentage of LPS was found for the TE when bulk fitted, and the lowest percentage of LPS was found in the Hand NE when incrementally fitted. The resin dentin bond strength was higher and the total mean gap width was tower for TE group; no significant effect was detected for the main factor fitting techniques. No difference was detected for the tensile strength of resin composite among the experimental groups.Conclusions: the filling technique is not able to minimize effects of the polymerization shrinkage, and bonding to the cavity watts is necessary to assure reduced mean gap width and high bond strength values. (C) 2004 Elsevier Ltd. All rights reserved.