Orientador: Alexandre Augusto Zaia / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-16T14:55:33Z (GMT). No. of bitstreams: 1 Sarmento_Naelka_M.pdf: 4681309 bytes, checksum: 93b3b378f28c8753a75a32deec716bcd (MD5) Previous issue date: 2010 / Resumo: O objetivo desse trabalho foi analisar a limpeza de túbulos dentinários após a desobturação do canal radicular com ou sem o uso de eucaliptol, através de microscopia eletrônica de varredura. Foram empregados neste estudo 100 raízes de primeiros molares superiores e inferiores. Como critério de inclusão as raízes selecionados deveriam apresentar-se retilínea, sem cáries, fissuras ou fraturas radiculares. O preparo químico-mecânico foi realizado com solução de hipoclorito de sódio 5% e EDTA 17% ou clorexidina gel 2% e EDTA 17%. As 100 raízes foram divididas em 5 grupos (Grupo A, B, C, D e E) aleatoriamente, as quais foram obturadas com cimentos endodônticos Endométhasone-N, Sealapex, AH Plus e Epiphany. Decorrido o tempo de pressa conforme recomendação do fabricante foi realizada a desobturação com eucaliptol para os subgrupos A1, B1, C1, D1 e E1; e sem o uso de eucaliptol, usando somente água destilada para os subgrupos A2, B2, C2, D2 e E2. As raízes foram fraturadas no eixo longitudinal e analisadas em microscópio eletrônico de varredura (SEM). Quando se fez uso de solvente os cimentos resinosos apresentaram melhor limpeza nas regiões cervical e média. Os cimentos a base de óxido de zinco e eugenol apresentaram limpeza precária nos terços médio e apical quando desobturados com água. O terço apical mostrou maior quantidade de detritos independente do cimento utilizados, fazendo-se ou não o uso de solventes / Abstract: The aim of this study was to analyze the cleanliness of the dentinal tubules after root canal removal procedure with or without the use of eucalyptol, by scanning electron microscopy (SEM). Used in this study were 100 roots of the first upper and lower molars. The inclusion criterion roots selected should present itself straight, no cavities, cracks or root fractures. The chemo-mechanical preparation was accomplished with a solution of sodium hypochlorite 5% and EDTA 17% or chlorhexidine gel 2% and 17% EDTA. The 100 roots were divided into five groups (Group A, B, C, D and E) randomly, which were sealed with sealers Endométhasone-N, Sealapex, AH Plus and Epiphany. Elapsed time to setting as recommended by the manufacturer was performed with the removal procedure eucalyptol for subgroups A1, B1, C1, D1, E1, and without the use of eucalyptol, using only distilled water for subgroups A2, B2, C2, D2 and E2. The roots were fractured in the longitudinal axis and analyzed by scanning electron microscopy (SEM). When use was made of solvent resin sealer showed better cleaning in the cervical and middle. The sealer of zinc oxide and eugenol showed poor cleaning in the middle and apical thirds when unstop with water. The apical third showed a larger amount of debris regardless of the cement used, making it or not the use of solvents / Mestrado / Endodontia / Mestre em Clínica Odontológica

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O presente estudo teve por objetivo avaliar o efeito das interações moleculares entre solventes e monômeros com a matriz de dentina desmineralizada, nas alterações das propriedades mecânicas, na taxa de evaporação e na resistência de união (RU). As propriedades mecânicas da dentina desmineralizada foram determinadas através da análise do módulo de elasticidade máximo aparente (EMax) e do relaxamento das tensões (RT). Os resultados permitiram concluir que o Emax foi dependente do tipo de solvente utilizado e do tempo. A taxa de enrijecimento da matriz desmineralizada foi maior para acetona e etanol, intermediária para o ar, metanol e propanol, menor para o HEMA e praticamente nenhuma para água. Da mesma forma, o RT dependeu da solução em que os espécimes foram equilibrados, previamente ao ensaio mecânico, e do tipo de deformação induzida ao espécime. De uma maneira geral, a resposta da matriz desmineralizada (RT) foi maior quando equilibrada em acetona, propanol e etanol, intermediária para HEMA, butanol e metanol e menor para água. A tensão máxima gerada com o tempo foi maior quanto maior a deformação inicial induzida (3-5-10%). A taxa de evaporação e a perda de massa total (%) de misturas experimentais à base de 35%HEMA/65%solventes foram determinadas através da medida de perda de massa em função do tempo, a partir de duas superfícies distintas (cubos de dentina desmineralizados x superfície livre). A taxa de evaporação e a perda de massa foi maior para HEMA/acetona (H/AC) e HEMA/metanol (H/M), intermediária para HEMA/etanol (H/E) e menor para HEMA/água (H/A), sendo esses valores superiores a partir dos cubos de dentina. A RU foi determinada pelo emprego do teste de microtração. Para verificar a influência do aspecto de brilho superficial, foram aplicadas 2 ou 3 camadas de misturas experimentais (35%HEMA/65%solventes) sobre a dentina previamente condicionada. Os maiores valores de RU foram obtidos com a manutenção do brilho superficial para todas as soluções testadas (ou seja, com a aplicação de 3 camadas). A durabilidade da RU obtida com o uso das soluções experimentais (35%HEMA/65%solventes) aplicadas sobre dentina desmineralizada seca foi avaliada após 24hs , 6 meses ou 1 ano de armazenagem em água deionizada. O valor de RU sofreu uma redução com a referida armazenagem para a maioria das soluções testadas. Os maiores valores de RU foram obtidos para H/M e H/E em todos os períodos avaliados. Este estudo desenvolveu uma linha de raciocínio que empregou a teoria dos parâmetros de solubilidade para descrever e analisar as interações moleculares que ocorrem durante a execução de um procedimento adesivo à dentina, procurando estabelecer as relações de causa e efeito. / The present study aimed to test the effect of the molecular interactions between solvent and pure monomers with demineralized dentin matrix on its mechanical properties, evaporation rate and consequent change in the bond strength (BS). The mechanical properties were determined by measuring the apparent maximum modulus of elasticity (EMax) and stress relaxation (SR). The results indicated that the Emax is both time and solvent dependent; accordingly, the SR was both strain and solvent dependent. The weight loss (%) and evaporation rate of experimental mixtures (35%HEMA/65%solvents) were determined by the measuring of weight loss over time from different surfaces (demineralized dentin cubes x free surface). The overall evaporation rate and weight loss were higher for dentin cubes and dependent of solvents. The bond strength (BS) was determined by the microtensile test. The effects of surface shininess on bond strength of experimental primers to dentin were evaluated. Dentin surfaces were acidetched, primed with experimental mixtures in two (not shiny) or three (shiny) coats. For the all primers the presence of a shiny surface significantly improved resin-dentin bond strengths. The influence of storage time in resin dentin bond strength mediated by experimental HEMA/solvent primers was determined. Part of specimens were tested after 24 hour storage in deionized water (control) and remaining specimens were tested after 6 months and 1 year of storage in the same condition. Water storage resulted in reduced bond strength for most of the primers. This study develops a rationale that employs the solubility parameter theory to describe and analyze molecular interactions that occur during adhesive procedure to dentin, seeking to establish the cause-effect relationship.

Membranes are a robust, reliable and economical technology. However, polymeric membranes are manufactured from polymeric and organic solvent sources derived from petrochemical sources. The high volatile organic compounds (VOC) emissions of the organic solvents and the non-recyclability of the polymers often question the membrane manufacture sustainability. The main goal of this dissertation is the preparation of polymeric membranes for liquid separation through more sustainable processes. We report here the green preparations of hollow fibers, thin-film composite and integrally skinned asymmetric membranes. An important part of the work is represented by the development of cellulose hollow fibers from ionic liquid solutions, avoiding strong alkali or harsh solvents. By tuning the manufacturing process, we prove that the membranes can be used for different applications such as oil-water separation, protein separation via ion-exchange chromatography and solvent purification via organic solvent nanofiltration. The main advantages of using cellulose to prepare hollow fiber membranes are the biodegradability of the polymer and the intrinsic chemical stability. Another significant milestone of this work is replacing volatile solvents such as hexane during the thin-film composite membrane manufacture. As green alternative solvents, we decided to use naturally extracted oleic acid and decanoic acid. Due to their low costs and volatility, they represent a valid alternative for industrial membrane preparation through the interfacial polymerization process. The membranes prepared with this process were used for solvent resistant nanofiltration. Finally, by using ionic liquids as solvents, we improved the manufacturing sustainability polytriazole asymmetric membranes synthesized in the lab.

The aim of this work is the preparation of porous polymeric membranes for liquid separations stable in organic solvents, high temperature and/or extreme acid or basic conditions. Polymeric membranes with these properties could replace more traditional and energy-expensive separation processes like distillation, competing with ceramic membranes due to their easy processability and scalability. A limited library of polymers have been successfully used for decades in water-based applications. They are however unstable in organic solvents without an additional treatment, which is usually a crosslinking reaction. In this dissertation different highperformance polymeric membranes and crosslinking strategies are presented and discussed, allowing their use in harsh environments. We present for the first time the preparation of porous membranes using poly(oxindole) derivatives. These polymers were prepared by superacid catalyzed polyhydroxyalkylation, which is a novel one-pot, room-temperature, metal-free polymerization method. The obtained polymers were fully characterized and then manufactured into membranes by the non-solvent induced phase separation method. The crosslinking of these membranes was achieved by different protocols. First, we reacted the oxindole group in the polymer backbone with a variety of dibromides of different chemical structure. Secondly, we incorporated a propargyl side group, followed by a crosslinking in hot glycerol. Moreover, the strategy of crosslinking using propargyl as pendant group was successfully demonstrated in membranes made of poly(benzimidazole) and poly(triazolebisphenol-AF). And thirdly, we prepared membranes from hydroxyl-functionalized poly(oxindole), and conducted a controlled thermal oxidation, which resulted in the crosslinking by phenoxy radicals. In each case, the resulting membranes achieved insolubility in polar aprotic organic solvents, high resistance in acid medium and had high decomposition temperatures. In each case, the resulting membranes achieved not only insolubility in polar aprotic organic solvents and resistance to acid media but also showed high decomposition temperatures. Finally, we demonstrated for the first time the preparation of porous membranes based on recycled poly(ethylene terephthalate) plastic bottles and their potential application for separations in an organic solvent medium.

No description available.

Muscadine seeds from three cultivars (‘Carlos’, ‘Noble’ and ‘Ison’) were processed by 100% v:v methanol, 95% v:v ethanol and 70% v:v acetone. The acetone seed extracts exhibited the highest (p<0.05) total phenolics (21.62~24.84mg/g of dw) and antioxidant activity. A strong correlation (R2=0.891, p<0.01) was found between total phenolics and antioxidant activity. Methanol and ‘Carlos’ seed extracts generally showed the highest antimicrobial capacity against pathogen strains tested, which correlated well with tannic acid, catechin, epicatechin and tartaric acid content. Hot water-soluble muscadine skin extracts from 17 muscadine cultivars (6 bronze and 11 dark) showed effective antioxidant properties. Significant variations (p<0.05) were observed among the 17 cultivars in total phenolics, organic acids and antioxidant activity. ‘Alachua’, ‘Albermarle’, ‘Southland’, ‘Janebell’ and ‘CA9-37’ were the cultivars found to have the highest antioxidant capacity. Skin extracts of dark-skin cultivars showed higher (p<0.05) content than bronze-skin cultivars in phenolics, tartaric acid, tannic acid and ellagic acids.

No description available.