O objetivo deste trabalho foi comparar sistemas adesivos de fabricação nacional - Magic Bond DE (Vigodent), Master Bond (Biodinâmica) e Self Etch Bond (Vigodent) e similares importados - Adper Single Bond 2 (3M/ESPE) e Clearfil SE Bond (Kuraray) por meio da avaliação da resistência de união, resistência à tração e micromorfologia da interface. Para a avaliação da resistência de união foram utilizados vinte e cinco molares humanos hígidos (n=5). Os dentes foram preparados de modo a obterem-se superfícies planas em dentina, sobre as quais os sistemas adesivos foram aplicados seguindo as instruções dos fabricantes. Após 24 horas de armazenamento em água destilada a 37oC os dentes restaurados foram seccionados para obterem-se corpos-de-prova com área aderida de aproximadamente 0,8mm2. Metade dos corpos-de-prova foi submetida imediatamente ao teste de microtração, com velocidade de 0,5 mm/min até o momento da fratura. Os demais corpos de prova foram armazenados por mais 6 meses antes da realização do teste. A resistência à tração foi avaliada em corposde- prova (n=10) usinados em forma de haltere, com secção transversal aproximada de 0,4 mm2. O teste foi realizado em períodos idênticos aos do ensaio de microtração. Para a análise em microscopia eletrônica de varredura dois dentes foram preparados para cada sistema adesivo. Os valores obtidos foram submetidos à análise de variância e teste de correlação de Pearson. Os resultados obtidos no teste de resistência de união mostraram que, em 24 horas, os sistemas Adper Single Bond 2 e Master Bond apresentaram médias superiores aos demais sistemas adesivos nacionais e inferiores ao sistema importado Clearfil SE Bond. Já após 6 meses, os dois sistemas importados foram superiores aos nacionais. Considerando os valores obtidos no teste de resistência à tração, os sistemas nacionais foram similares entre si nos dois momentos de avaliação. O sistema Clearfil SE Bond apresentou a maior média em 24 horas e média similar a dos sistemas nacionais após o armazenamento, com a maior redução nos valores de resistência à tração. O sistema Adper Single Bond 2 apresentou as menores médias nos dois períodos. Não foi encontrada correlação entre as variáveis resistência de união e resistência à tração. Na análise em microscopia eletrônica de varredura, interfaces defeituosas foram observadas para os sistemas adesivos nacionais, com exceção das formadas pelo sistema Master Bond. Os sistemas adesivos nacionais, exceto o Self Etch Bond, tiveram a durabilidade da união comprometida, o que não ocorreu com os similares importados. A resistência mecânica dos sistemas adesivos não influenciou a resistência de união proporcionada, em nenhum dos períodos avaliados. / The aim of this study was to compare national adhesive systems to similar imported materials by microtensile bond strength test, tensile strength and SEM evaluation. The adhesive systems evaluated were Magic Bond DE (Vigodent), Master Bond (Biodinâmica) and Self Etch Bond (Vigodent), from national manufacturer and similar imported materials Adper Single Bond 2 (3M/ESPE) and Clearfil SE Bond (Kuraray). For bond strength evaluation twenty five sound human molars were used, divided into five groups and prepared in order to obtain flat dentin surfaces in which the adhesive systems were applied following manufacturers instructions and resin blocks were made. After 24 hours of storage in distilled water at 37oC restores teeth were sectioned in order to obtain specimen with a bonded area of around 0,8mm2. Half of the specimen were immediately submitted to the test with a crosshead speed of 0,5 mm/min until fracture the other specimen were stored for additional 6 month prior to the test. Tensile strength was evaluated in adhesive dumbbell trimmed specimen with cross section area of around 0,4 mm2. The test was performed at the same storage periods used in the bond strength test. For the SEM analysis two teeth with each material were prepared. The values were submitted to ANOVA and Pearson correlation. The results of bond strength showed that in 24 hours Adper Single Bond 2 and Master Bond produced higher values compared to the other systems and lower than Clearfil SE Bond. After 6 months the two imported materials were superior to the national adhesive systems. Regarding tensile strength the national adhesive systems were similar to each other in both periods. Clearfil SE Bond showed the highest mean in 24 hours and after 6 months was similar to national adhesive systems. Adper Single Bond 2 showed the lower means in both periods. No correlation was found between bond strength and tensile strength. In SEM analisys defective interfaces were found to national adhesive systems excluding Master Bond. National adhesive systems bond strength longevity was compromised, excluding Self Etch Bond. After storage Clearfil SE Bond diminished tensile strength. In both storage times tensile strength did not influenced bond strength.

Orientador: João Neudenir Arioli Filho / Banca: Sérgio Russi / Banca: Sergio Sualdini Nogueira / Banca: Cláudia Helena Lovato da Silva / Banca: Helena de Freitas Oliveira Paranhos / Resumo: O objetivo deste estudo foi analisar a influência da incorporação de três desinfetantes (hipoclorito de sódio a 1%, glutaraldeído alcalino a 2% e digluconato de clorexidina a 2%) em duas diferentes porcentagens de substituição da água da espatulação (50 e 100%) de dois gessos tipo IV, FujiRock EP (M1) e Rock Plus (M2), avaliando-se a resistência à compressão e à tração diametral. Os corpos-de-prova foram obtidos a partir de matrizes metálicas bipartidas com 20 mm de diâmetro e 40 mm de altura (resistência à compressão) e 20 mm de diâmetro e 10 mm de altura (resistência à tração diametral). As matrizes foram fixadas sobre uma placa de vidro, o gesso foi manipulado na proporção água/pó recomendada pelos fabricantes (M1:20ml/100g e M2:19 ml/100g), em um espatulador mecânico por 30 segundos, e vazado sob vibração. Para cada ensaio foram confeccionados sete grupos para cada gesso (n=10). Os grupos foram: CONTROLE (Água destilada), G50 (substituição de 50% da água de espatulação por glutaraldeído), G100 (100% de glutaraldeído), C50 (substituição de 50% da água por clorexidina), C100 (100% de clorexidina), H50 (substituição de 50% da água por hipoclorito) e H100 (100% de hipoclorito). Após a presa os corpos-de-prova foram removidos das matrizes e armazenados à temperatura ambiente. Os ensaio de compressão e tração diametral foram realizados 24 horas após o vazamento, em uma máquina de ensaios MTS-810, com célula de carga de 100 KN à velocidade de 0,5mm/min. Os valores médios de resistência à compressão e à tração diametral (MPa) foram submetidos à análise de variância e teste de Tukey, com nível de significância de 95%, permitindo concluir que: (a) a incorporação das substâncias desinfetantes estudadas afetou a resistência à compressão de ambos os gessos analisados; (b) as diferentes proporções de incorporação das substâncias... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The purpose of this study was to evaluate the compressive and diametral tensile strength of two Type IV dental stones, FujiRock EP (M1) e Rock Plus (M2), mixed with three disinfectant solutions (sodium hypochlorite 1%, chlorhexidine digluconate 2% and glutaraldehyde 2%) in two different proportions of gauging water (50% and 100%). Compressive samples consisted of cylindrical specimens, each having a diameter of 20 mm and length of 40 mm, and diametral tensile specimens consisted of discshaped specimens, having a diameter of 20 mm and length of 10 mm, obtained from split metal molds. The stone was mixed with the solutions previously outlined at the water-powder ratio recommended by the manufacturers (M1:20ml/100g e M2:19 ml/100g), mechanically spatulated under vacuum (Turbomix) for 30 seconds, and gently vibrated in the molds. Seven groups were prepared for each test, with 10 samples each, as follows: CONTROL (distilled water), G50 (substitution of 50% of gauging water by glutaraldehyde), G100 (only glutaraldehyde), C50 (substitution of 50% of gauging water by chlorhexidine digluconate), C100 (only chlorhexidine digluconate), H50 (substitution of 50% of gauging water by sodium hypochlorite) and H100 (only sodium hypochlorite). Specimens were removed from the molds after they set. Compressive strength and diametral tensile strength was determined 24 hours the specimens were cast, in an MTS-810 testing machine, with a cross-head speed of 0,5mm/min. Mean compressive and diametral tensile strength was calculated and expressed in megapascals (MPa). Data from both tests were analyzed by ANOVA and Tukey test, showing that: (a) chemical disinfectants incorporation reduced the compressive strength of type IV dental stones evaluated; (b) the use of two different proportions of gauging water substitution by disinfectants (50% and 100%) has affected the compressive strength of only one die stone (M1); (c) chemical disinfectants incorporation did not reduced. / Doutor

Resumo: A proposta deste estudo foi avaliar por meio do teste de microtração a resistência de união de um sistema adesivo irradiado com laser de Nd:YAG em dentina preparada com laser de Er:YAG. Estudos prévios têm demonstrado que a irradiação com laser após a aplicação do sistema adesivo é eficiente em alcançar alta força de união à tensão e ao cisalhamento. O laser de Er:YAG (Twinlight, Fotona, Eslovênia) com fluência de 60 J/cm2 foi usado para o tratamento da dentina. A irradiação do adesivo foi realizada usando o laser de Nd:YAG (Twinlight, Fotona, Eslovênia) com fluência de 100 J/cm2. As restaurações foram executadas com Adper Single Bond 2/Z250 (3M/ESPE, EUA). Vinte terceiros molares recentemente extraídos e livres de cárie foram empregados. Os dentes foram divididos em quatro grupos experimentais (n = 5): (G1) grupo controle onde não houve irradiação; (G2) irradiação do sistema adesivo com laser de Nd:YAG; (G3) tratamento da dentina com laser de Er:YAG; (G4) tratamento da dentina com laser de Er:YAG mais irradiação do sistema adesivo com laser de Nd:YAG. Um dente de cada grupo foi preparado para avaliação da interface adesiva sob microscopia eletrônica de varredura (MEV). Adicionalmente foi realizada a análise do padrão de fraturas, resultante dos ensaios mecânicos, sob microscopia óptica digital. Os testes de microtração foram realizados em uma máquina de ensaios mecânicos com célula de carga de 1 kN a uma velocidade de 0,5 mm/min. A análise estatística (ANOVA e teste de Tukey), dos dados referentes aos ensaios mecânicos, evidenciaram diferença estatística significante entre os grupos G1 e G3, G1 e G4, G2 e G3, e G2 e G4 e semelhança entre os grupos G1 e G2, e G3 e G4. As fraturas adesivas foram predominantes em todos os grupos experimentais. / Abstract: The purpose of this study was to verify through micro tensile bond test the bond strength of an adhesive system irradiated with Nd:YAG laser in dentine treated with Er:YAG laser. Previous studies had shown that laser irradiation after the application of an adhesive system is efficient in achieving higher shear bond and tensile bond strength. Er:YAG laser (Twinlight, Fotona, Slovenia) with fluency of the 60 J/cm2 was used for the treatment of the dentine. The irradiation of the adhesive was performed using the Nd:YAG laser (Twinlight, Fotona, Slovenia) with the fluency of the 100 J/cm2. Dental restorations were performed with Adper Single Bond 2/Z250 (3m/ESPE, USA). Twenty caries free extracted human third molars were used. The teeth were divided in four experimental groups (n = 5): (G1) control group where there was no irradiation; (G2) irradiation of the adhesive system with the Nd:YAG laser; (G3) treatment of the dentin with Er:YAG laser; (G4) treatment of the dentin with Er:YAG laser plus irradiation of the adhesive system with Nd:YAG laser. One tooth of each group was prepared for evaluation of adhesive interface under scanning electron microscopy (SEM). In addition was performed an evaluation of the bond failures under digital optic microscopy. The micro tensile bond tests were performed in a MTS universal testing machine with 1 kN load cell at cross-head speed 0,5 mm/min. The statistical analysis (ANOVA and Tukey test) showed difference significant statistics between the groups G1 and G3, G1 and G4, G2 and G3, and G2 and G4; and similarity between the groups G1 and G2, and G3 and G4. The adhesive failures were predominant in all experimental groups. / Orientador: Rosane de Fátima Zanirato Lizarelli / Coorientador: Marcelo Ferrarezi de Andrade / Banca: José Eduardo Pelizon Pelino / Banca: Sizenando de Toledo Porto Neto / Mestre

Made available in DSpace on 2017-07-10T14:17:14Z (GMT). No. of bitstreams: 1 Dissertacaoo Mestrado em_ Odontologia - Jamille Favarao.pdf: 2385935 bytes, checksum: 4cc351f6120333258bdde1aeb42d56b7 (MD5) Previous issue date: 2015-02-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Purpose: Evaluate the bond strength to dentin of three different bonding system (conventional 3 steps, two steps and universal self-etching) after 1 week and 6 months in oral environment. Methods: Class I cavities were prepared in third molars of 30 patients, that were randomly divided into 3 groups according to the adhesive system used, Scotchbond Multipurpose (SM), Clearfil Protect Bond (CF) and Scotchbond Universal (UN) and subdivided in two groups according to the length of stay in the oral environment, 1 week (1S) and 6 months (6M). After standing in the oral environment, teeth were extracted, cut into sticks and subjected to microtensile test. Data were submitted to Shapiro-Wilk test and ANOVA (two-way), followed by Tukey post hoc, significance level of 5 % and the fracture pattern analyzed. Results: Average values (MPa ± SD) of the groups were SM-1S: 39.50 ± 7.92; 6M-MS: 29.68 ± 1.82; CF-1S: 30.48 ± 1.44 CF-6M: 28.59 ± 4.13; UN-1S: 30.62 ± 3.24; UN-6M: 26.71 ± 2.05. There was significant difference for both, the adhesive system factor and the time factor. The SM -1S group showed resistance values significantly higher than the other groups, with no differences between them. The fracture analysis showed predominance of mixed fracture for group 1 and adhesive fracture to the other groups. Clinical Significance; The findings of this study indicate that the studied adhesive systems presented similar bond strength after 6 months in the oral environment / Objetivo: Avaliar a resistência de união à dentina de três diferentes sistemas adesivos (convencional de 3 passos, autocondicionante de 2 passos e universal) após 1 semana e 6 meses em meio bucal. Métodos: Foram prepararas cavidades Classe I em terceiros molares de 30 pacientes, distribuídos aleatoriamente em 3 grupos de acordo com o sistema adesivo utilizado, Scotchbond Multipurpose (SM), Clearfil Protect Bond (CF) e Scotchbond Universal (UN) e, subdividos em dois grupos de acordo com o tempo de permanência em meio bucal, 1 semana (1S) e 6 meses (6M). Após permanência em meio bucal os dentes foram extraídos, seccionados em palitos e submetidos ao teste de microtração. Os dados foram submetidos ao teste de Shapiro-Wilk e ao teste de ANOVA (dois critérios), seguidos do teste post hoc de Tukey, nível de significância de 5% e o padrão de fratura analisado. Resultados: Os valores médios (MPa ± DP) dos grupos foram, SM-1S: 39,50 ± 7,92; SM-6M: 29,68 ± 1,82; CF-1S: 30,48 ± 1,44 CF-6M: 28,59 ± 4,13; UN-1S: 30,62 ± 3,24; UN-6M: 26,71 ± 2,05. Houve diferença significante tanto para o fator sistema adesivo, como para o fator tempo. O grupo SM-1S apresentou valores de resistência a microtração significativamente maiores que os demais grupos, que não apresentaram diferenças entre si. A análise de fratura mostrou predominância de fratura mista para o grupo SM-1S e fratura adesiva para os demais grupos. Significado Clínico: Os achados desse estudo indicam que os sistemas adesivos estudados apresentaram resistência de união semelhante após 6 meses em meio bucal.

A Implantodontia proporciona tratamentos com alto grau de sucesso clínico nas reabilitações com próteses parafusadas ou cimentadas. A alta taxa de sobrevivência dos implantes, seu sucesso clínico significativo e a grande previsibilidade levaram a uma mudança de paradigma na Implantodontia atual. O uso de implantes, antes utilizados para a reposição de grandes perdas dentárias, é aplicado também para perdas parciais de dentes e até mesmo elementos unitários. Com isso a dificuldade técnica diminuiu ainda mais, consolidando o uso de próteses cimentadas sobre implantes. Desta forma a reversibilidade, que é o principal recurso das próteses parafusadas sobre implantes, não é mais decisiva na escolha do tipo de sistema de retenção. Entretanto, as próteses cimentadas apresentam desvantagens que podem levar a um fracasso do tratamento. Dentre elas o acúmulo do excesso de cimento, que pode levar a uma inflamação do tecido periimplantar com a possível perda do implante. Existem na literatura técnicas de cimentação que visam à redução do agente cimentante em excesso. Outro fator estudado é a influência da rugosidade da superfície do munhão protético na resistência ao arrancamento do elemento protético. O objetivo do estudo foi realizar uma análise da resistência ao arrancamento de coroas cimentadas sobre munhões protéticos polidos e asperizados, utilizando uma técnica experimental de cimentação. Foram confeccionados quarenta corpos de prova e formaram-se quatro grupos de estudo, de acordo com a técnica de cimentação utilizada (técnica controle e técnica experimental) e a rugosidade das paredes do munhão protético (polido e asperizado). As coroas foram cimentadas com o cimento de Fosfato de Zinco. A análise da resistência ao arrancamento foi realizada, após a ciclagem térmica dos quarenta corpos de prova, utilizando uma máquina de ensaio universal. Na análise das técnicas de cimentação pôde-se observar que não ocorreram diferenças estatisticamente significativas entre os grupos, com valores médios de resistência ao arrancamento de 157,83 N ± 22,16 N para o grupo técnica controle-superfície polida e 159,95 N ± 46,40 N para o grupo técnica experimental-superfície polida. A análise dos dados nos grupos técnica controle-superfície asperizada (626,23 N ± 34,80 N) e técnica experimental-superfície asperizada (642,62 N ± 94,00 N), também não indicaram diferenças significativas. Na análise dos grupos, comparando a rugosidade da superfície, pôde-se observar diferenças significativas, com valores de 157,83 N ± 22,16 N para o grupo técnica controle-superfície polida e 626,23 N ± 34,80 N para o grupo técnica controle-superfície asperizada. O mesmo foi observado no grupo técnica experimental-superfície polida com valores de 159,95 N ± 46,40 N e 642,62 N ± 94,00 N para o grupo técnica experimental-superfície asperizada. Conclui-se que, nas condições utilizadas neste estudo, a técnica de cimentação experimental não apresentou diferenças significativas com a técnica controle, em relação à resistência ao arrancamento, nas duas superfícies (polida e asperizada) utilizadas no estudo. A asperização das paredes axiais dos munhões levou a um aumento significativo da resistência ao arrancamento nas duas técnicas de cimentação estudadas. / The Implantology provides treatments with high clinical success rate in screw or cement retained rehabilitations. The high survival rate of the implants, its significant clinical success, and the great predictability led to a paradigm shift in current Implantology. The dental implant, previously used for replacing large teeth losses, is also applied to partial dental losses and even single tooth replacement. Therefore, technical difficulties have decreased even more, which consolidated the use of cement retained implant prosthesis. Thus the retrievability, which is the main resource of screw retained implant prostheses, is not the crucial point in the prosthesis retention selection. However, cement retained prostheses have disadvantages that can lead to treatment failure. One can mention the presence of residual excess cement, which may lead to an inflammation of the peri-implant tissue, or even a possible implant loss. There are in the literature cementation techniques that reduce the luting agent excess. Another studied factor is the influence of the prosthetic abutment surface roughness in the prosthetic element tensile strength. The aim of the study was to analyze the tensile strength of prosthetic crowns cemented on standard machined and sand blasted abutments using an experimental cementation technique. Forty specimens were fabricated and four experimental groups were formed, according to the cementation technique (control technique and experimental technique) and the prosthetic abutment roughness (standard machined and sand blasted). The crowns were cemented with zinc phosphate cement. The tensile strength analysis was performed, after the forty specimens thermal cycling, using an universal testing machine. In the cementation techniques analysis it was observed that there were no statistically significant differences between the groups, with mean tensile strength values of 157.83N±22.16N for the control technique- standard machined surface and 159.95N±46.40N for the experimental technique-standard machined surface. The data analysis of control technique-sand blasted surface group (626.23 N±34.80N) and experimental technique-sand blasted surface group (642.62 N±94.00N) also indicated no significant differences. In the group analysis, comparing the surface roughness, it was observed significant differences, with values of 157.83N±22.16N for the control technique-standard machined surface group and 626.23N±34.80N for the control technique-sand blasted surface group. The same was observed in the experimental technique-standard machined surface group with 159.95N±46.40N values and 642.62N±94.00N for the experimental technique-sand blasted surface group. It can be concluded that, under the study conditions, the experimental cementation technique showed no significant differences with the control technique, regarding tensile strength, in the two surfaces (standard machined and sand blasted) used in the study. The prosthetic abutments roughening led to a significant increase in tensile strength on the two studied cementation techniques.

Carbon nanotube (CNT)/polymer composite sheets can be extremely high strength and lightweight, which makes them attractive for fabrication of mechanical structures. This thesis demonstrates a method whereby smooth, thin CNT/polymer composite sheets can be fabricated and patterned on the microscale using a process of photolithography and plasma etching. CNT/polymer composites were made from CNTs grown using chemical vapor deposition using supported catalyst growth and floating catalyst growth. The composite sheets had a roughness of approximately 30nm and were about 61¼m or 261¼m depending on whether they were made from supported catalyst grown or floating catalyst grown CNTs. The composites were patterned using an oxygen plasma as the etchant and a hard mask of silicon nitride.

Laboratory experiments were conducted to observe, document and evaluate the mechanical behavior of Fiber Reinforced Concrete after being submitted to five different environments for 8 months. The specimens were molded and reinforced with synthetic fibers with a composition similar to that used for dry-cast concrete. Four different types of fibers with different composition were used. The fibers were mixed with the concrete to create the samples and the samples were exposed to different environmental conditions. Some of these environments were meant to increase degradation of the interface fiber-concrete to simulate longevity and imitate harsh environments or marine conditions. The environments consisted of: a high humidity locker (laboratory conditions), submerged in the Intracoastal Waterway in a barge (SeaTech), a wet/dry cycle in seawater immersion simulating a splash/tidal zone, low pH wet/dry seawater immersion cycle and samples submerged in calcium hydroxide solution. The latter three were in an elevated temperature tank (87-95°F) to increase degradation process. The specimens were monitored weekly and the environments were controlled. Then, specimens were evaluated using different mechanical testing as the Indirect Tensile (IDT) test method, compressive strength according to ASTM standards. Results of testing were documented and observed in this study for further understanding of mechanical properties of Fiber Reinforced concrete. Forensic observation of fiber distribution after the IDT tests were also performed. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection

The sphingolipid, ceramide-1-phosphate (C1P), directly binds and activates Group IVA cytosolic phospholipase A2 (cPLA2a) to generate eicosanoids. Due to the role of eicosanoids in wound healing, we choose to use our novel genetic mouse model expressing cPLA2a with an ablated C1P interaction site (KI) to examine the cPLA2a/C1P interaction in wound healing. Wound closure rate was not affected, but wound maturation was dramatically enhanced by loss of the C1P/cPLA2α interaction based on the following findings. Wounds in KI mice displayed: i) increased infiltration of dermal fibroblasts into the wound environment; ii) increased wound tensile strength; and iii) higher Type I/Type III collagen ratios. These findings were recapitulated in vitro as primary dermal fibroblasts (pDFs) from KI mice showed significantly increased collagen deposition and migration velocity compared to WT and KO pDFs. Additionally, the KI showed an altered eicosanoid profile of reduced pro-inflammatory prostaglandins (e.g., PGE2) and increased levels of specific HETE species (e.g., 5-HETE). Elevated 5-HETE levels promoted increased dermal fibroblast migration and collagen deposition. This “gain of function” role for the mutant cPLA2a was also linked to differential cellular localization of cPLA2α and 5-HETE biosynthetic factors. These studies demonstrate regulation of key in vivo biological mechanisms by a defined protein:lipid interaction and provide new insights into cPLA2a function.

Companies providing products have many requirements, both from standards and customers, that they need to comply with in order to be able to sell their product. Veoneer AB is a leading automotive machine vision supplier, providing mono, stereo, night vision and driver monitoring systems consisting of both electronic, mechanical and optical components. These systems have to withstand certain environmental tests in order to assure the lifetime of the totalsystems. Since the life time is usually several years accelerated tests are used that correspond to a few weeks ormonths. The tests used at Veoneer are specified for electronic equipment and what Veoneer does not know today is ifthe accelerated environmental tests stated for electronic equipment are relevant for the optical component of the visionsystem. In this master thesis project two different accelerated environmental tests, dry and damp heat, have been chosen inorder to investigate the effect of temperature and relative humidity on the adhesive in the optical component connecting the sensor and lens. The optical components where characterized by measurement of focus position and mechanicalstrength. Different combinations of temperature and relative humidity where chosen in order to compare the effect of different stress levels but also for the purpose of deriving parameters needed for accelerated testing models such as theArrhenius, Eyring, Lawson and Peck model. Amongst the results from this thesis work is the focus shift measurement which follows the same trend as seen in previous research regarding the effect of temperature and relative humidity on adhesives. With an exponentialdistribution being seen in different directions for the respective stresses. Pull tests show a greater degradation withhigher stress levels, where one test case shows the greatest degradation. Calculations regarding activation energy and constants for models match previous research where one model, combining temperature and relative humidity, showssimilar values as found in literature. Calculations also show that standard accelerated life time tests overexpose adhesives due to calculations of test times with lower activation energies.

Orientador: Rebeca Di Nicoló / Coorientadora: Fernanda Alves Feitosa / Banca: Eduardo Bresciani / Banca: Eduardo Galera da Silva / Banca: Levy Anderson Cesar Alves / Banca: Fabio Matuda / Resumo: O objetivo desta pesquisa foi avaliar a influência da utilização ou não do bond do sistema adesivo Adper Scotchbond Multiuso(A) e o bond Gluma da Heraeus(G) na resistência de união entre as resinas do tipo flow Filtek Bulk Fill Flow(F) e X-tra base (X) como base e uma convencional nanoparticulada Z350 XT(Z)) como cobertura. Simulando assim seu uso em reparos de restaurações diretas em dentes posteriores. Foram confeccionados 120 espécimes em resina composta do tipo flow no formato tronco-cônico com as dimensões de 2mm base menor, 4mm de altura e 4 mm de base maior. 60 Filtek Bulk Fill(F) e 60 X-tra base (X). Metade de cada grupo (n=30) foi envelhecida por termociclagem 5.000 ciclos de 5°C a 55°C, (FE, XE), a outra metade não sofreu envelhecimento (FN e XN). Esses espécimes foram divididos em 3 subgrupos (n=10), sobre a base menor dessas 10 amostras foi aplicado o Bond de cada sistema adesivo após condicionadas pelos seus respectivos ácidos nos tempos preconizados pelos fabricantes. As outras 10 unidades de cada grupo não receberam qualquer sistema adesivo. Na simulação do reparo as duas primeiras metades em teflon foram invertidas ficando a área menor voltada pra cima. Sobre essa face foram colocadas outras duas metades em teflon com a área menor voltada para baixo. Foi inserida então a resina Z350 pela técnica incremental e fotopolimerizada por 20s a 800mw/cm². Após 24h de armazenamento em água destilada, em estufa bacteriológica os espécimes, agora com formato de ampulheta,... (Resumo completo, clicar acesso eletrônico abaixo) / The aim of our paper was to analyse the bonding influence of Adper Scotchbond Multipurpose Adhesive (A) and Heraeus Gluma universal bond (G), or no bond application, on bond strength between microhibrid Filtek Bulk Fill Flow (F) and nanohibrid X-tra base (X) as based composite resin and the conventional nanoparticulate Z350 XT (Z)) as cover. Simulating non-invasive repairs of direct restorations on posterior teeth. A total of 120 specimens were made from flow composite resin in the conical trunk format with the dimensions of 2x4x4, for 40s with Led-5 (N/S LD51803005) at 800mw/cm². Sixty Filtek bulk fill (F) and sixty X-tra base (X) were made. Half of each group (n=30) was aged by thermocycling 5,000 cycles from 5° C to 55° C, (FE, XE), the other half were not subjected to any aging procedure (FN, XN). These specimens were randomly divided into 3 subgroups (n = 10), on the smaller diameter of the 10 samples the Bond of each adhesive system were applied after conditioned by their respectively acids at the time recommended by the manufacturers. The other 10 units of each group did not receive any adhesive system. In the sequency of repair simulation the first two Teflon halves were turned up with the smaller diameter turned upwards. Above this face were placed two other halves in Teflon with the smaller diameter facing down. The Z350 repair composite resin were inserted by incremental technique and photopolymerized for 20s at 800mw/cm². After 24h of storage in distilled water in a bacteriological oven, the now hourglass-shaped specimens were drawn in the universal testing machine EMIC. All the fractured specimens had the type of failure analyzed in stereomicroscope. The most significant faulting specimens were evaluated with electronic microscope (MEV). The data collected at the traction test were analyzed through 3-factor ANOVA and Tukey's test (p <5%). There was... (Complete abstract click electronic access below) / Doutor