As alterações de superfície dos implantes de titânio (Ti) influenciam funções celulares e formação de tecido adjacente aos mesmos, mas é controverso se tais alterações trariam vantagens quando esses implantes fossem colocados em tecido ósseo de baixa qualidade. O objetivo deste estudo foi avaliar a resposta do tecido ósseo de baixa qualidade (tipo IV) a implantes de Ti com diferentes tratamentos de superfície. Para isso, implantes de Ti com superfície nanotexturizada (Ti-Nano), microtexturizada (Ti-Porous) e sem tratamento de superfície (Ti-Usinado) foram implantados em tíbias de coelhos. Após duas e seis semanas, o tecido ósseo formado ao redor dos implantes foi avaliado em cortes histológicos por desgaste e histomorfometricamente foram avaliados: a porcentagem de contato ossoimplante (BIC), porcentagem de área de osso mineralizado formado entre as espiras do implante (BABT), porcentagem da área de osso formada na área espelho (BAMA). Vários outros parâmetros morfométricos foram avaliados a partir de imagens e reconstruções tridimensionais obtidos por microtomografia. Ao final de seis semanas, foi avaliado o torque de remoção. Os resultados foram submetidos à análise de variância (ANOVA) com dois fatores de variação (tratamento de superfície e tempo de implantação) seguido do teste de Tukey (p≤0,05). Apesar de algumas diferenças estatisticamente significantes para alguns dos parâmetros morfométricos, tais diferenças não são biologicamente importantes para que pudessem ser atribuídas aos tratamentos de superfície. Tanto que, histologicamente não se observou diferença nos padrões de formação óssea ou tipo de osso formado que pudesse ser associado aos tratamentos de superfície e o torque de remoção também não foi afetado pelos tratamentos. Em conclusão, esses resultados mostraram que os tratamentos de superfície, embora sejam na escala micrométrica ou nanométrica, não induzem repostas do tecido ósseo tipo IV diferentes daquelas induzidas por superfícies sem tratamento. / Some alterations in titanium (Ti) implant surfaces influence cell functions and tissue formation in areas adjacent to the implants, but it is controversial whether these changes would bring advantages when these implants were placed in bone of poor quality. The aim of this study was to evaluate the response of poor quality bone tissue (type IV) to Ti implants with different surface treatments. For this, Ti implants with nanotextured surface (Ti-Nano), microtextured (Ti-Porous) and without surface treatment (Ti-Machined) were implanted into tibias of rabbits. After two and six weeks, the bone tissue around the implants was assessed in undecalcified histological sections and histomorphometrical analysis to evaluate: the percentage of bone-implant contact (BIC), percentage of the area of mineralized bone formed between threads (BABT), the percentage area of bone formed in the mirror area (BAMA). Several other morphometric parameters were evaluated from images and three-dimensional reconstructions obtained by microtomography. At the end of six weeks the removal torque was evaluated. The results were subjected to analysis of variance (ANOVA) with two factors of variation (surface treatment and time) followed by Tukey test (p≤0.05). Despite some statistically significant differences for some of the morphometric parameters, such differences are not biologically important and they could not be attributed to the surface treatments. In keeping with this, histological analysis failed to show any difference in bone formation that could be associated to the surface treatments and removal torque was not affected by treatments either. In conclusion, these results showed that the surface treatments, irrespective of being on the micrometer or nanometer scale, do not induce responses of type IV bone tissue different from those induced by untreated surfaces.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-01-13T18:22:43Z No. of bitstreams: 1 nataliavelosomalta.pdf: 1376730 bytes, checksum: cdeb2bd74c09e4792776e296bd5f7f42 (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2017-01-31T10:32:11Z (GMT) No. of bitstreams: 1 nataliavelosomalta.pdf: 1376730 bytes, checksum: cdeb2bd74c09e4792776e296bd5f7f42 (MD5) / Made available in DSpace on 2017-01-31T10:32:11Z (GMT). No. of bitstreams: 1 nataliavelosomalta.pdf: 1376730 bytes, checksum: cdeb2bd74c09e4792776e296bd5f7f42 (MD5) Previous issue date: 2016-06-09 / O objetivo desse estudo foi avaliar, a influência de duas diferentes técnicas de aplicação de glaze (pincél e spray) sobre a morfologia de superfície de uma cerâmica Y-TZP (IPS e.maxR®ZirCAD (IvoclarVivadent) antes e após a aplicação do ácido fluorídrico. Foram confeccionados 20 corpos de prova a partir de 4 blocos cerâmicos de zircônia parcialmente estabilizada por ítria pré-sinterizados, que foram divididos em 5 grupos (n=4) de acordo com o tratamento de superfície recebido: C= controle (nenhum tratamento de superfície); S: glaze spray VITA AKZENT( Vita Zanhfabrik )P/L: glaze pó/líquido VITA AKZENT (Vita Zanhfabrik,) S+HF: S + condicionamento com ácido fluorídrico 10% (HF)(FGM) (1min); P/L + HF: P/L + condicionamento com HF 10% (1min). As amostras forma então submetidas ao seguintes testes: 1) goniometria, para ánalise do ângulo de contato e da energia de superfície; 2) análise dos dados de rugosidade (Ra) por meio de um perfilômetro óptico digital; 3)identificação das fases cristalinas do material pela Difratometria de Raios X; 4) análise dos elementos químicos presentes no material cerâmico por Microscopia e espectrometria por energia dispersiva (EDS); 5) análise da superfície por meio de microscopia eletrônica de varredura (MEV). Os resultados demonstraram que: 1) a superfície das amostras tratadas com o glaze pó/líquido foram as que apresentaram uma camada mais espessa de glaze, com superfícies menos rugosas; 2)o grupo que recebeu o tratamento com o glaze pó/líquido foi o que apresentou a maior energia de superfície (69,83mN/m), e os demais grupos apresentaram elevados valores de ângulos de contato; 3) o tratamento térmico de vitrificação não causou alterações de fases na estrutura da zircônia; 4)As imagens de perfilometria e MEV revelaram um padrão irregular de disposição do glaze após o condicionamento com HF 10%, e um alto conteúdo de sílica foi observado somente nos grupos P/L e P/L + HF. O estudo concluiu que a utilização do glaze pó/líquido pela técnica do pincel promoveu uma maior padronização da camada de glaze e foi método de tratamento de superfície que apresentou uma maior energia de superfície e um maior conteúdo vítreo. Pelas imagens de microscopia, pode-se observar que a aplicação do ácido fluorídrico a 10% criou microretenções sobre a camada de glaze pó-liquido que podem favorecer a adesão a esta superfície. / The present study evaluated qualitatively the influence of two different types of glaze (brush and spray) on the surface of Y-TZP ceramics (IPS e.maxR® ZirCAD (IvoclarVivadent,) before and after use of hydrofluoric acid. Twenty specimens were made from 4 zirconia ceramic blocks partially stabilized by pre-sintered yttria, which were divided into 5 groups (n=5) according to the surface treatment received: C = Zirconia (control) (no surface treatment); S: glaze spray VITA AKZENT; P/L: glaze powder/liquid VITA AKZENT, S+HF: S + etching with hidrofluoridric acid 10% (HF)(FGM) (1min); P/L + HF: P/L + etching with HF 10% (1min).Samples were then subjected to the following tests: 1) Goniometry for analysis of the contact angle and the surface energy ; 2) Analysis of roughness data (Ra) by means of a digital optical profilometer; 3) Identification of the crystalline phases of the material by X-ray diffraction;4) Analysis of the chemical elements present in the ceramic material by microscopy and energy dispersive spectrometry (EDS); 5) analysis of the surface after each surface treatment by means of scanning electron microscopy (SEM).Partial results showed that: 1) The surface of the samples treated with glaze powder/liquid showed a thicker layer of glaze with less rough surfaces; 2) the group receiving treatment with glaze powder/liquid presented higher surface energy (69,83mN/m), while the other groups showed high values of contact angles; 3) thermal treatment of vitrification did not change the phases of zirconia surface; 4) The SEM and profilometry images revealed a glaze irregular pattern layout after etching with 10% HF, and a high silica content was observed only in GP / L and GP / L + HF groups. The study concluded that use of the glaze powder / liquid by brush technique promoted a greater standardization of the glaze layer and this surface treatment method was the one that showed a higher surface energy and a higher glassy content. For microscopy images, it can be seen that the application of hydrofluoric acid 10% created micro retentions on the glaze powder-liquid layer that can promote adhesion to this surface.

Diante dos avanços científicos da odontologia visando o selamento perfeito das cavidades com adesão, desenvolvimento de materiais, técnicas e maior compreensão das características do substrato dental, a tecnologia a laser de Er:YAG (2,94 mm) apresenta-se como recurso eficiente para o tratamento superficial da dentina, isoladamente ou em associação ao condicionamento ácido, em baixa densidade de energia. Para obtenção de uma zona microrretentiva (camada híbrida, tags e microtags) mais uniforme e evitarem-se aspectos críticos de adesão como o colapso da trama protéica, sua remoção pela desproteinização com hipoclorito de sódio (NaOCl) tem sido proposta. O presente estudo teve por objetivo pesquisar a interação de diferentes tratamentos superficiais em dentina bovina (condicionamento ácido convencional, laser de Er:YAG e desproteinização), avaliar a resistência adesiva à tração utilizando-se um sistema adesivo à base de acetona, e analisar as superfícies dentinárias submetidas a estes diferentes tratamentos em microscopia eletrônica de varredura (MEV). Verificou-se que o laser de Er:YAG em baixa densidade de energia (19,29 J / cm2, a 60 mJ e 2 Hz) pôde influenciar positivamente na resistência adesiva da dentina, comparando-se ao condicionamento ácido convencional. A associação laser e ácido no tratamento de superfície dentinária aumentou a resistência adesiva independente de ter-se realizado ou não a desproteinização. A observação em MEV das superfícies dentinárias tratadas com o laser de Er:YAG seguido da desproteinização com NaOCl revelou aspecto morfológico microrretentivo, embora o comportamento adesivo tenha produzido baixos valores de resistência à tração. / Under scientific improvements in dentistry towards the perfect cavity sealing and adhesion, the development of materials, techniques and the better understanding of dental substrate features, the Er:YAG laser (2,94 mm) technology plays a role as an efficient tool in dentin surface treatment, performed in low energy density, whether isolated or in association with acid etching. In order to obtain a more uniform mircro-retentive zone (hybrid layer, tags and microtags) and to avoid the critical aspects on adhesion such as the collagenous demineralized zone collapse, it has been proposed the removal of this collagenous zone with the sodium hypochlorite (NaOCl) protein depletion technique. The aim of the present study was to evaluate the interaction of these surface treatments in bovine dentin (conventional acid etching. Er:YAG laser and protein depletion), to measure the tensile bond strength of the treated dentin surfaces, by using an acetone-based adhesive system and to observe the dentin surfaces under scanning electron microscopy analysis (SEM). The results showed that Er:YAG laser performed in low energy density (19,29 J / cm2, at 60 mJ and 2 Hz) could positively influence in dentin tensile strength, as good as conventional acid etching. The laser / acid association in dentin treatment increased tensile bond strength whether had it been performed the NaOCl protein depletion or not. SEM observation of Er:YAG dentin treated surfaces followed by NaOCl had shown a morphologic micro-retentive pattern; however, its tensile bond strength values came out to be low.

The objective of the present study was to evaluate the bond bond strength of intraradicular glass fiber post submitted to different surface treatments and cemented on the root dentin with resin cement adhesive. 40 straight roots of upper incisors extracted for clinical purposes were used in this research (without treatment, silane, 35% hydrogen peroxide, sodium bicarbonate). The post were cemented with resin cement adhesive relyx U200. Twenty four hours after cementing the post, the root were cut crosswise so then producing 1,0 mm inch specimens. The specimens in the format of hourglass were submitted to microtensile tests in order to obtain the amounts of adhesive strength and also to verify the fracture pattern. Two samples of the control group were prepared for analysis using scanning electron microscopy in order to map the adhesive interface. After data collecting, the samples were submitted to ANOVA and test of Tukey statistical analysis. Therefore, these tests were verify differences in the bond strength and allow descriptive analysis of adhesive interface. There was a statistically significant different between the different glass fiber post surface treatments C, Sil, Per and Bic (p = 0.0018 <0.05). There was a statistically significant different between the regions of root dentin (p = 0.0034 <0.05), respectively, coronal region - (19.1 (± 3.71), 25.6 (± 4.3), 24.4 (± 3.16); 30.2 (± 13.0) - showed the highest bond strength values that the root middle third (14.6 (± 4.6), 12.5 (± 5.0), 10.6 (± 3.3), 10.87 (± 2:48). Within the limits of experimental procedures, it can be concluded that treating the surface of the fiber post with chemical and physical agents increases the bond strength of glass fiber post for independent of root dentin canal. / Este estudo avaliou a resistência de união de pinos intraradiculares submetidos a diferentes tratamentos de superfície e cimentados com cimento resinoso autoadesivo à dentina radicular. Foram utilizados na pesquisa 40 raízes retas de caninos superiores, extraídos por motivos clínicos. Os dentes foram divididos aleatoriamente em 4 grupos, de acordo com o tratamento de superfície do pino (Sem tratamento (C), Silano (Sil), Peróxido de Hidrogênio 35% (Per), Bicarbonato de Sódio (Bic). Os pinos foram cimentados com o cimento resinoso autoadesivo RelyX U200. Vinte e quatro horas após a cimentação dos pinos, as raízes foram cortadas transversalmente de forma a produzir espécimes de espessura de 1,0 mm. Os espécimes em forma de ampulheta foram submetidos ao teste de micro-tração para obtenção de valores de resistência adesiva e verificação do padrão de fratura. Duas amostras do grupo controle foram preparadas para análise em microscopia eletrônica de varredura para mapeamento da interface adesiva. Após a coleta dos dados, os mesmos foram submetidos a análise estatística ANOVA e teste de Tukey para verificação de diferenças de resistência adesiva e análise descritiva para interface adesiva. A análise de variância acusou diferença estatisticamente significante entre os diferentes tratamentos de superfície do pino de fibra de vidro - C, Sil, Per e Bic (p= 0.002 ). Houve diferença estatisticamente significativa entre as regiões da dentina radicular, (p=0.003), sendo que a região cervical (19.1 (±3.71); 25,6 (±4.03); 24.4 (±3.16); 30.2 (±13.0)) mostrou os maiores valores que no terço médio radicular (14.6 (±4.6); 12.5 (±5.0); 10.6 (±3.3); 10.87(±2.48)). Dentro das limitações dos procedimentos experimentais, pode ser concluído que o tratamento da superfície dos pinos de fibra com agentes químicos e físicos, aumenta a resistência de união de pinos de fibra de vidro à dentina radicular no terço cervical.

Abstract Whenever a foreign material is implanted into a human body an implant–tissue interface area forms between them. In this microenvironment, interactions take place between the implant and the surrounding tissue. The implantation of a biomaterial into tissue results in injury and initiation of the inflammatory response. This host response to biomaterials is an unavoidable series of events that occur when tissue homeostasis is disturbed by the implantation process. In bone tissue, biocompatible implants must initially be capable of strong bone implant contact and subsequently, allow the normal bone remodeling cycle around the implant. NiTi is a metal alloy composed of approximately a 50:50 ratio of nickel and titanium. It possesses shape memory and superelasticity properties, which make it an interesting biomaterial. NiTi has two phases: austenite and martensite. A decrease in temperature or applied stress induce the austenite-to-martensite transformation. Heating or removing the stress restores the parent austenite phase. The alloy in its martensite structure can be reshaped and strained several times more than a conventional metal alloy without irreversible deformation of the material. The alloy returns to its original shape as it changes from martensite-to-austenite. This transformation is seen as the macroscopic shape memory effect. This study further investigated the biocompatibility of NiTi, especially the bone cell response to both austenite and martensite. Different surface treatments were investigated in order to improve and possibly even control NiTi's bioactivity as a bone implant material. Osteoclasts grew and attached well on the austenite NiTi phase, but the results indicated that the biocompatibility of martensite NiTi was compromised. Oxidation of the NiTi surface improved osteoblast attachment and viability. This was due to the formation of a TiO2 surface layer of moderate thickness. Coating the NiTi surface with the extracellular matrix protein fibronectin was shown to enhance osteoblast proliferation and increase the number of cells in the G1 cell cycle stage. Austenite was more prone to show these effects than martensite. A sol-gel derived titania-silica surface treatment was observed to increase the bone implant contact of functional NiTi intramedullary nails. The surface treatment was most effective with the constant bending load provided by the NiTi nail.

Ce travail de thèse s’est porté sur l’étude des alliages d’aluminium, et en particulier les alliages AA2024-T3 et AA2050-T3. L’alliage AA2024-T3 à base d’Al-Cu-Mg est utilisé depuis des décennies dans le domaine de l’aérospatial pour sa légèreté et ses excellentes propriétés mécaniques, est progressivement remplacé par les alliages Al-Cu-Li tels que l’AA2050-T3. Néanmoins, il en résulte parallèlement une microstructure très hétérogène, rendant l’AA2024 très sensible à la corrosion. Plusieurs moyens de protections - appelés traitements de surface- ont donc été développés, dans le but de ralentir au maximum la dégradation de l’alliage. Le prétraitement, une étape préliminaire au traitement de surface a pour but de préparer la surface de l’alliage. Plusieurs études ont démontré que cette étape est indispensable et assure l’efficacité du traitement de surface. Afin d’observer l’effet du prétraitement, plusieurs techniques de caractérisations de surface sont utilisées. La microscopie électronique à balayage (MEB) et la spectroscopie à photoélectron X (XPS) sont parmi les plus citées. Toutes ces méthodes ont pour objectif de s’assurer de la dissolution des éléments d’alliages, et de mettre en évidence les effets d’enrichissement de cuivre. Jusqu'à présent, aucune méthode n’a permis d’obtenir une analyse complète et in situ de la réactivité de tous les éléments lors du prétraitement. L’objectif principal de ces travaux de thèse était de développer une nouvelle méthodologie, capable de prodiguer une mesure précise de la réactivité d’alliages complexes tels que les alliages d’aluminium durant une séquence de prétraitement et d’apporter des informations sur le AA2050-T3, pour lequel la littérature est beaucoup plus pauvre en données quant à la réactivité de l’élément d’alliage Li avec les solutions de prétraitement. / This PhD thesis focused on the study of aluminum alloys, particularly the AA2024-T3 and AA2050-T3. The Al-Cu-Mg based alloy (AA2024-T3) are used for decades in the field of aerospace for its lightness and excellent mechanical properties are progressively replaced by and Al-Cu-Li (AA2050-T3) alloys. Nevertheless, they exhibit a highly heterogeneous microstructure, making them sensitive to corrosion. Several surface treatments formulations, such as coatings, have been developed, with the aim of slowing as much as possible the degradation of these alloys. The pretreatment, a preliminary step to surface treatment, is intended to prepare the surface of the alloy prior coating application. Several studies have shown that this step is essential and ensures the effectiveness of the surface treatment. In order to observe the effect of the pretreatment, several surface characterization techniques were used. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) are among the most cited. All these methods are intended to quantify the dissolution of the alloying elements. To date, none has been able to obtain a complete and in situ analysis of the elemental reactivity of a complex alloy during the pretreatment. The main objective of this thesis was to develop a new methodology capable of providing a precise measurement of the reactivity of complex alloys such as aluminum alloys during a pretreatment sequence and to provide information on AA2050 -T3, as very little is reported about the reactivity of Li during the surface treatment.

Plasma electrolytic Polishing (PeP) is a non-conventional technology for the surface treatment of electrically conductive materials. It is an effective machining technique for cleaning and polishing of metals and considered as a more environmentally friendly alternative to the electropolishing process. The electropolishing process uses aggressive media such as acids, whereas in PeP, acids or toxicants are replaced by low concentrated water solutions of various salts. In PeP, high DC voltage is applied to the electrodes in the aqueous electrolyte solution, which establishes a thin steam-gas layer around the surface of the work piece resulting in the generation of plasma. From the previous research, it is found that the formation of stable plasma generally takes place between 180-370 volts, where it results in better surface conditions. The aim of this study is to analyse the behaviour of current according to different voltages and their effects on surface roughness and material removal rate (MRR) of stainless steel in Plasma electrolytic Polishing process.

Hipótese do Estudo: O presente estudo hipotetizou que superfícies tratadas de discos de titânio comercialmente puro (Ti c.p.) são mais susceptíveis a aderência bacteriana que as superfícies lisas. Objetivo: O objetivo deste trabalho foi avaliar, in situ, a aderência bacteriana em discos de Ti c.p. submetidos a dois diferentes tratamentos de superfície: duplo ataque ácido e anodização. Metodologia: Sessenta corpos-de-prova de Ti c.p. foram divididos em três grupos: Grupo 1 - discos de Ti c.p. liso (grupo controle); Grupo 2 - discos de Ti c.p. com superfície duplamente condicionada com ácido (Master Pours Implant, Conexão Sistemas Prótese LTDA, SP., Brasil) e o Grupo 3 - discos de Ti c.p. submetidos à irradiação laser (Vulcano Actives, Conexão Sistemas Prótese LTDA, SP., Brasil). Inicialmente foi avaliada a rugosidade superficial (Ra) de todos os corpos-de-prova. Para a avaliação in situ, foram confeccionadas dez moldeiras individuais e em cada uma delas fixados seis discos de titânio, sendo dois de cada grupo. Dez voluntários usaram, por 24 horas, a moldeira contendo os discos de Ti c.p. Após este período três discos de titânio de cada grupo foram levados ao Microscópio Eletrônico de Varredura (MEV) para visualização do biofilme formado. O biofilme foi removido dos 17 discos restantes e, em sete deles, foi realizado o ensaio de MTT para quantificar as bactérias viáveis e em dez a Reação em Cadeia de Polimerase em Tempo Real (PCR Real Time, quantitativo) para quantificação total das bactérias aderidas e do Streptococcus oralis. Resultados: Os dados obtidos foram estatisticamente analisados utilizando Análise de Variância (ANOVA) One Way, seguido do pós-teste de Tamhane. Com relação a Ra, a diferença observada entres os Grupos 3 e 1 foi de 0,652 0,098&#956;m e entre os Grupos 3 e 2 de 0,688 0,099&#956;m. Nas micrografias foi observado biofilme aderido em todos os discos de titânio. O ensaio de MTT não evidenciou diferença significativa entre os grupos Grupo 1 (0,1190,048), 2 (0,1360,079) e 3 (0,1210,074), p=0,89. Os resultados da PCR Real Time não evidenciaram diferença significativa quanto ao número de bactérias entre os grupos estudados, tanto para o Universal (UN), Grupos 1- 372.477 (87.556;889.408), Grupo 2- 294.834 (51.742;648.674) e Grupo 3- 497.393 (150.596;2.333.567) com valor de p=0,88, quanto para o Streptococcus oralis (SO), Grupos 1-3.623(262;31.603), Grupo 2- 477(154;42.292) e Grupo 3- 9.002(1.053;147.154) com valor de p=0,42. Conclusões: Os discos do grupo 1 apresentaram rugosidade superficial igual aos do grupo 2 e ambos uma rugosidade superficial menor que os discos do grupo 3. A adesão bacteriana não foi influenciada pela rugosidade superficial dos discos de titânio. Não foi observada diferença significante na adesão bacteriana entre os grupos estudados, tanto pelo ensaio de MTT, quanto pela PCR real time. / Hypothesis of the Study: This study hypothesized that treated surfaces of discs commercially pure titanium (CP Ti) discs are more susceptible to bacterial adhesion than smooth surfaces. Objective: The objective of this study was to evaluate in situ the bacterial adherence in cp Ti discs subjected to two different surface treatments: double etching and anodizing. Methods: Sixty Ti specimens were divided into three groups: Group 1 - smooth cp Ti discs (control group), Group 2 - cp double Ti discs with surface acid etching (Master Pours Implant , Connection Prosthesis Systems LTD, SP., Brazil) and Group 3 - laser irradiated cp Ti discs subjected (Vulcan Actives , Connection Implant Systems LTD, SP., Brazil). Initially we evaluated the surface roughness (Ra) of all specimens. To assess in situ, individual trays were prepared and ten in each set of six disc titanium, two in each group. Ten volunteers wore what for 24 hours, the tray containing discs cpTi After this period three titanium disks from each group were taken to the Scanning Electron Microscope (SEM) to visualize the biofilm. The biofilm was removed from the 17 remaining disks, and seven of them, was held by the colorimetric MTT method to quantify living cells and ten to Real Time Polymerase Chain Reaction (Real Time PCR) for quantification of adhered bacteria and Streptococcus oralis. Results: Data were statistically analyzed using analysis of variance (ANOVA) One Way, followed by post-test Tamhane. With respect to Ra, the difference observed between the groups 3:01 was 0.652 0.098 m and between Groups 3 and 2 of 0.688 0.099 micrometers. In micrographs biofilm attached was observed in all titanium disks. The MTT method showed no significant difference among groups Group 1 (0.119 0.048), 2 (0.136 0.079) and 3 (0.121 0.074), p = 0.89. The Real Time PCR results showed no significant difference in number bacterial between the groups for both the Universal (UN), Group 1- 372.477 (87.556;889.408), Group 2- 294.834 (51.742;648.674) and Group 3- 497.393 (150.596;2.333.567) with p = 0, 88, as for Streptococcus oralis (SO), Group 1- 3.623(262;31.603), Group 2- 477(154;42.292) and Group 3- 9.002(1.053;147.154) with p = 0.42. Conclusions: The disks of group 1 showed surface roughness equal to Group 2 and both had a surface roughness smaller than the disks of group 3. The bacterial adhesion was not influenced by the surface roughness of the titanium disks. There was no significant difference in bacterial adhesion between the groups, both by MTT method, and by real time PCR.

Este trabalho apresenta um estudo relacionado a três estados de superfície aplicados em um substrato de aço ferramenta AISI H13 temperado e revenido utilizado no processo de calibração a frio para a fabricação de forjados de precisão, os quais posteriormente processados transformam-se em componentes de um semieixo homocinético. O foco deste trabalho foi demostrar através da aplicação de tratamentos de superfície o aumento do desempenho em termos de resistência ao desgaste na interface da superfície da ferramenta em análise e também correlacionar com o seu custo benefício do produto final, visto que o critério para avaliação de vida útil depende diretamente do dimensional final do forjado. Para a comparação e o teste industrial foram estipuladas três condições diferentes de superfície para serem avaliadas. A primeira sem revestimento, a segunda com modificação superficial pelo processo de nitretação gasosa e a terceira com revestimento Dúplex PVD a base de CrTiN. A caracterização das amostras foram realizadas com o auxílio de microscopia eletrônica de varredura, análises metalográficas de microestrutura e dureza. A partir dos resultados obtidos foi constatado que o revestimento Dúplex aplicado em ferramentas para calibração a frio apresentou o melhor desempenho em relação às outras duas condições propostas. O revestimento Dúplex obteve um ganho de 400% em vida útil de ferramentas correlacionado a melhor resistência ao desgaste e, além disso, uma melhor performance em seu comportamento dimensional perante ao processo aplicado. Como segunda alternativa, as ferramentas com o processo de nitretação gasosa atingiram uma redução de 17% nos custos de ferramentas por peças produzidas e acréscimo de 20% em vida útil de ferramentas, apresentando uma melhora em relação as ferramentas sem tratamento de superfície. / This work presents a study related to three surface states applied on a quenching and tempered AISI H13 tool steel substrate used in the cold calibration process for the manufacture of precision forgings, which are subsequently processed into components of a halfshafts. This dissertation aims at demonstrating, through the application of surface treatments, the increase in the wear resistance performance of the tool under analysis and correlating this with cost benefit in the final product, since the end life criterion for the tools depends directly on the dimensions of the forged part. For comparison and industrial testing three different surface conditions were stipulated for evaluation. The first uncoated, the second with surface modification by the gas nitriding process and the third with PVD duplex coating based on CrTiN. The characterization of the samples was carried out with Optical and Scanning Electron Microscopy, Metallographic Analysis of the Microstructure and Hardness Tests. According with obtained results it was verified that the treatment duplex coating applied in tools for cold calibration presented the best performance in relation to the other two conditions proposed. The duplex coating obtained a gain of 400% in tool life correlated to better resistance to wear and, in addition, a better performance in its dimensional behavior in relation to the previous condition without surface treatment. As a second alternative, the tools treated by the gas nitriding process achieved a 17% reduction in tooling costs per parts produced and a 20% increase in tool life, showing an improvement over tools without surface treatment.

The thesis is focused on the surface treatment used for the preparation of aluminium alloys for the adhesive bonding. The theoretical part can be divided into three chapters. The first of them deals with aluminium alloys, the second one speaks about the adhesive bonding. The surface treatment itself, especially the conversion coating issues, is discussed in the last chapter. The experimental part is focused on the optimalization of a two-step titanium and zirconium based conversion coating technology. In the first part, the aluminium alloy is analysed by the glow discharge optical emission spectroscopy. The second part of the experiment deals with the first step of the technology, acidic deoxidation. The objective was to examine the influence of the exposure time on the morphology of the alloy surface and the shear strength of adhesive joints. In the last part of the experiment, the conversion coatings are prepared and characterised by the scanning electron microscopy and energy dispersive spectroscopy.