Orientador: Marco Antonio Compagnoni / Banca: Ana Carolina Pero / Banca: Karin Hemana Neppelenbroek / Resumo: Proposição: O objetivo deste estudo foi avaliar o efeito da utilização de dois adesivos para prótese em relação ao desempenho mastigatório de usuários de próteses totais convencionais, por meio de um estudo "cross-over". Material e Método: Cinquenta indivíduos totalmente desdentados receberam novas próteses totais bimaxilares e, após o período de adaptação posterior à instalação, foram submetidos à análise do desempenho mastigatório com as próteses sem adesivos protéticos (controle). Posteriormente, a amostra foi dividida aleatoriamente e designada a dois protocolos, nos quais a ordem de uso dos adesivos era diferente. Os adesivos Ultra Corega creme e Ultra Corega pó foram utilizados por 15 dias previamente à aplicação de novas análises do desempenho mastigatório, por toda a amostra, e respeitando-se um período de descanso (washout), também de 15 dias, entre o uso de cada adesivo. O desempenho mastigatório foi avaliado pelo método dos tamises. Os dados obtidos foram submetidos ao teste não-paramétrico de Friedman e comparação múltipla de média de ordens utilizando o teste de DUNN (α=0,05). Resultados: Houve aumento significativo do desempenho mastigatório após uso dos adesivos Ultra Corega creme (med=27,4%) e Ultra Corega pó (med=28,0%), quando estes foram comparados ao grupo controle (med=16,5%) (p<0,001; n=30), não havendo diferença estatisticamente significante entre os adesivos testados (p=0,897; n=30). Conclusões: O uso de adesivos aumentou o desempenho mastigatório de usuários de próteses totais convencionais, e não houve diferença para o desempenho mastigatório quanto ao uso de adesivos nas formas de creme e pó. / Abstract: Objective: The objective of this study was evaluate the effect of use of two denture adhesives in relation to masticatory performance of conventional complete denture wearers, by means of a cross-over study. Material and Method: Fifty edentulous individuals received new bimaxillary complete dentures and, after the adaptation period, were submitted to masticatory performance analysis with complete dentures without adhesives (control). So, the sample was randomly divided and assigned to two protocols, in which the adhesives order of use was different. The adhesives Ultra Corega cream and Ultra Corega powder were used for 15 days prior the application of new masticatory performance analysis, by all the sample, and respecting a washout period, also 15 days, between the use of each adhesive. The masticatory performance was evaluated by sieves method. Data were analyzed by nonparametric Friedman test and multiple comparison of average orders using test DUNN (α=.05). Results: There was significant increase in masticatory performance after use of adhesives Ultra Corega cream (med=27.4%) and Ultra Corega powder (med=28.0%), when these were compared to the control group (med=16.5%) (p<.001; n=30), without statistically significant difference between the tested adhesives (p=0,897; n=30). Conclusions: The use of adhesives increased masticatory performance of conventional complete denture wearers, and there was no difference for masticatory performance as the use of adhesives in the forms of cream and powder. / Mestre

Adesivos sensíveis à pressão (PSA do inglês - Pressure Sensitive Adhesives) são produtos que aderem a superfícies imediatamente após a aplicação de pequenas pressões. Têm grandes vantagens sobre outros tipos de adesivos, principalmente por necessitarem apenas de uma aplicação inicial de pressão para apresentar o efeito permanente de adesão. Neste trabalho foram avaliadas três composições distintas de PSA, sendo uma delas considerada como referência, e duas condições diferentes de processamento, com o objetivo principal de obter um adesivo com alta resistência ao cisalhamento e boa aderência. Todas as amostras foram produzidas em laboratório utilizando um moinho de dois rolos e um misturador do tipo sigma. Essas composições foram baseadas em borrachas com insaturações, que permitem a formação de ligações cruzadas, tornando o adesivo mais resistente. As alterações impostas na composição (adição de óxido metálico e resinato) e a mudança na condição de processamento (nível de reação para formação de ligações cruzadas) levaram a diferentes propriedades dos adesivos obtidos; como valores de adesão, grau de ligação cruzada, resistência a cisalhamento e peso molecular. Os resultados encontrados neste trabalho mostram que a adição de 5pcr de óxido de zinco aumenta em até 64% a resistência ao cisalhamento em relação à amostra de referência, enquanto que 5 pcr de resinato de zinco causa um incremento de aproximadamente 21%. Também foi possível observar que o alto nível de reação (60 minutos) confere uma quantidade de ligações cruzadas pelo menos duas vezes maior que a obtido para o baixo nível de reação (30 minutos) / Pressure Sensitive Adhesives (PSA) are materials which bond to adherent surfaces at room temperature immediately as low pressure is applied. This kind of material has a number of advantages of adhesives bonding, especially because they need low pressure to effect permanent adhesion to an adherent. In this work three different PSA formulations were tested under two process condition. The final product obtained can be used over flexible web, as poly (vinyl chloride) tapes. Samples were prepared trough a two-roll mill and sigma mixer in a laboratory production scale. The composition was based on rubber material that has double molecular chain, which allows cross-linking, making the adhesive more resistant. Small changing on formulation (adding5phrofmetallic oxide or zinc resinate) and process condition (reaction level) took to different results as cross-link degree, adhesion properties, shear resistance and molecular weight. The results showed that adding small amount of metallic oxide can increase up to 64% of shear resistance and adding zinc resinate compound can increase about 21%. And also is possible to conclude that high reaction level (60 minutes) takes to at least double cross-linking degree compared with low reaction level (30 minutes)

No description available.

Orientador: Mario Fernando de Goes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-27T03:34:21Z (GMT). No. of bitstreams: 1 Guimaraes_IsadoraRabelo_D.pdf: 1408417 bytes, checksum: 663b3f486f91d8f3589f07a988f8ba2c (MD5) Previous issue date: 2015 / Resumo: O objetivo deste estudo foi avaliar o efeito da interação de sistemas adesivos multi-mode e cimentos resinosos de polimerização química e dual sobre a superfície da dentina. Quarenta terceiros molares humanos não cariados foram separados em 5 grupos (n=8). Uma superfície plana em dentina foi obtida para cada dente. Blocos de 3,0x12x12 mm de resina composta indireta (Lava Ultimate) foram jateados com partículas óxido de alumínio e cimentados na superfície de dentina, formando os seguintes grupos: I- All Bond Universal fotoativado (AB)/C&B Bond Cement (CB); II- Scotchbond Universal fotoativado (SBU)/RelyXUltimate químico (RXU); III- SBU fotoativado/RXU fotoativado, IV- SBU químico/RXU fotoativado, V- SBU químico /RXU químico. Após a cimentação, os dentes foram mantidos em umidade relativa a 37?C por 24 horas. Os dentes foram seccionados para obter palitos de aproximadamente 0,8 mm². Os espécimes foram posicionados na máquina de ensaio universal EZ-Test para o ensaio de resistência de união com uma velocidade de 0,5 mm/min. Os dados foram estatisticamente analisados por ANOVA um fator e Teste de Fisher's PLSD (?=0,05). Os modos de fratura foram analisados e classificados em microscópio eletrônico de varredura. Para análise das interfaces dentina/adesivo/cimento, cinco espécimes de cada grupo foram corados com Rodamina B a 1% por uma hora e analisados em microscópio confocal de varredura a laser. Nenhuma diferença estatística de resistência da união (MPa) foi observada entre os grupos: I- 59,9 (9,3); II- 57,6 (15,9); III- 63,9 (12,7) e IV- 53,7 (13,9), e todos foram diferentes estatisticamente do grupo V, que apresentou o menor valor de resistência da união 16,2 (6,4). O modo de fratura coesivo foi predominante na interface entre o adesivo e cimento resinoso em todos os grupos. A análise ultraestrutural sugere a interação entre os sistemas adesivos multi-mode e o cimento resinoso na dentina, quando o adesivo ou o cimento resinoso foi fotoativado. A interação adesiva ocorreu entre os adesivos multi-mode e cimentos resinosos, sempre que o adesivo e/ou o cimento resinoso foi fotoativado / Abstract: This study evaluated the dentin surface interaction effect of multi-mode adhesives on bonding to chemical-cured and dual-cured resin cements. Forty non-carious human third molars were divided into five groups (n=8). A flat dentin surface was created for each tooth. Indirect resin composite block 3,0x12x12 mm (Lava Ultimate) were sandblasted with aluminum oxide particles and cemented to the dentin surface following the treatment groups: I- All Bond Universal light-cured/C&B Bond (self-cured cement), II- Scotchbond Universal (SBU) light-cured/RelyX Ultimate (RXU) self-cured, III- SBU light-cured/RXU light-cured, IV - SBU no light-cured/RXU light-cured and V- SBU no light-cured/RXU self-cured. After 24 h, the teeth were sectioned into beans to produce a cross-sectional area of 0.8 mm². Specimens of each group were individually mounted on a jig and placed on a tensile testing universal machine. A tensile force was applied at a 0.5mm/min cross-speed. The bond strength was recorded and failure modes were classified using scanning electron microscopy. In order to observe dentin/adhesive-cement interface, selected beans from each group were stained with 0.1% Rodhamine B for 1 h and analyzed using Confocal Laser Scanning Microscopy. Statistical analysis was performed using ANOVA and Fisher¿s PLSD test (?=0.05). For bond strength (MPa) no statistical difference of was observed among the groups: I - 59.9 (9.3); II- 57.6 (15.9); III - 63.9 (12.7) and IV- 53.7 (13.9). Group V showed statistical lower average value 16.2 (6.4) compared with all others groups. Cohesive failure modes occurred predominately along of adhesive and resin cement to all groups. The ultrastructural observation suggested the dentin surface interaction between multi-mode adhesives and resin cement when the adhesive or resin cement was light-cured. The adhesive interaction occurred between multi-mode adhesive systems and resin cements whenever the adhesive and/or resin cement was light-activated / Doutorado / Materiais Dentarios / Doutora em Materiais Dentários

The increase in demand for corn ethanol has caused an increase in distiller’s dried grains with solubles (DDGS), which is a byproduct of ethanol production. DDGS is a cheap byproduct and is primarily used for livestock feed filler. DDGS contains oils and proteins from corn and in this research we showed that corn oil and proteins could be extracted with ethanol. Zein protein is the main protein in DDGS and has been shown to have good adhesive properties. This protein was used as a binder in biocomposites with the DDGS after extractions and soy protein isolate (SPI). Mechanical properties and water resistance of the composites were studied. A wood adhesive was also prepared using the zein and cellulose nano-fibrils (CNF) as the adhesive reinforcement. Rheological tests were performed to study the flow property of the adhesive. This research demonstrated the potential of DDGS to be used as a raw material for multiple value-added industrial uses.

The first part of the dissertation focuses on understanding and modeling the conduction mechanism of conductive adhesives. The contact resistance is measured between silver rods with different coating materials, and the relationship between tunnel resistivity and contact pressure is obtained based on the experimental results. Three dimensional microstructure models and resistor networks are built to simulate electrical conduction in conductive adhesives. The bulk resistivity of conductive adhesives is calculated from the computer-simulated model. The effects of the geometric properties of filler particles, such as size, shape and distribution, on electrical conductivity are studied by the method of factorial design. The second part of the dissertation evaluates the reliability and investigates the failure mechanism of conductive adhesives subjected to fatigue loading, moisture conditioning and drop impacts. In fatigue tests it is found that electrical conduction failure occurs prior to mechanical failure. The experimental data show that electrical fatigue life can be described well by the power law equation. The electrical failure of conductive adhesives in fatigue is due to the impaired epoxy-silver interfacial adhesion. Moisture uptake in conductive adhesives is measured after moisture conditioning and moisture recovery. The fatigue life of conductive adhesives is significantly shortened after moisture conditioning and moisture recovery. The moisture accelerates the debonding of silver flakes from epoxy resin, which results in a reduced fatigue life. Drop tests are performed on test vehicles with conductive adhesive joints. The electrical conduction failure happens at the same time as joint breakage. The drop failure life is found to be correlated with the strain energy caused by the drop impact, and a power law life model is proposed for drop tests. The fracture is found to be interfacial between the conductive adhesive joints and components/substrates. This research provides a comprehensive understanding of the conduction mechanism of conductive adhesives. The computer-simulated modeling approach presents a useful design tool for the conductive adhesive industry. The reliability tests and proposed failure mechanisms are helpful to prevent failure of conductive adhesives in electronic packages. Moreover, the fatigue and impact life models provide tools in product design and failure prediction of conductive adhesives.

Dissertation (Ph. D.)--University of Akron, Dept. of Polymer Engineering, 2007. / "May, 2007." Title from electronic dissertation title page (viewed 04/07/2008) Advisor, Erol Sancaktar; Committee members, Avraam I. Isayev, Sadhan C. Jana, Darrell H. Reneker, Shing-Chung Wong; Department Chair, Sadhan C. Jana; Dean of the College, George R. Newkome; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.

Thesis (M.S. in oral sciences)--University of Illinois at Chicago, 1998. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S. in oral sciences)--University of Illinois at Chicago, 1998. / Includes bibliographical references.

published_or_final_version / Botany / Doctoral / Doctor of Philosophy