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Possibly, MaybeMassard, Jessica January 2013 (has links)
Possibly, Maybe is an exhibition of polychromatic, process-based objects made out of acrylic paint. Working with and against the limits of the material, the paint is systematically cast, peeled, and stretched colour by colour transforming it into three-dimensional hybrid forms. The working process I devise is predetermined and regulated, yet the element of chance is integral to the work due to material constraints. I explore the sculptural potential and plasticity of a material traditionally used for painting. While acrylic is a relatively new material, designed to be durable and long lasting, the forms I create out of acrylic paint are vulnerable to climate, gravity, and time and therefore counter plastic’s perceived resilience. Possibly, Maybe looks within the marginalized and the failed of our everyday, and uses these as aesthetic elements, which can constitute contemporary cultural potential. Through an engagement with the fallibility of plastic, with the hybridity of artistic practice, and the excess, opulence, and decay of the Baroque, my work plays with the paradoxes and relationships between the high and the low, pure and impure, precious and throw-away, which I find are all elements that exemplify our contemporary culture.
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Estudo in vitro da adaptação de retentores intra-radiculares fundidos, modelados com diferentes resinas acrílicas autopolimerizáveis / In vitro study of the fit of cast post and core, obtained from different acrylic resin patternsRennó, Denise Galhardo 21 September 2005 (has links)
Dentes tratados endodonticamente se encontram freqüentemente mutilados por cárie ou pelo próprio acesso ao canal. A estrutura dental remanescente necessita de tratamento especial para prevenir futuras fraturas. Quando uma grande parte da coroa dental foi perdida, é comum não haver retenção para a restauração na dentina remanescente. Nestas situações, uma restauração com retenção intracanal se faz necessária. Apenas a porção radicular pode oferecer a retenção apropriada para a instalação de uma coroa artificial estética e funcional. Diferentes técnicas podem ser usadas para a fabricação do retentor intra-radicular fundido. Neste estudo, foi escolhida a técnica direta para a confecção dos padrões de fundição em resina acrílica autopolimerizável. Usamos seis padrões metálicos com dimensões que simulavam dentes anteriores preparados para receber um retentor intra-radicular. Os condutos foram preenchidos com resina acrílica, usando um pincel bem fino, e pinos plásticos foram inseridos no interior dos canais. Após a polimerização do pino, adicionamos novas porções de resina acrílica para confecção das partes correspondentes aos núcleos. Essa técnica permite a correção de eventuais falhas, caso haja necessidade. Os padrões de fundição foram então incluídos em material de revestimento e fundidos em liga de níquel-cromo. O retentor intra-radicular fundido foi removido do revestimento e limpo. Apenas removemos os nódulos da superfície do metal, a qual recebeu, posteriormente, jateamento com óxido de alumínio. O objetivo deste estudo foi comparar a adaptação marginal de 54 retentores intra-radiculares fundidos, modelados com três resinas acrílicas autopolimerizáveis diferentes: 18 em DuraLay (Reliance Dental MFG Co., USA); 18 em Pattern Resin (GC Products, Japan); 18 em Cop Clas (Artigos Odontológicos Clássico Ltda., Brasil). Os retentores intra-radiculares fundidos foram assentados sobre os seis padrões metálicos. As fendas marginais foram observadas em microscópio eletrônico de varredura (MEV). As medições foram registradas e submetidas à análise estatística. Os resultados obtidos mostraram que: (1) Os retentores intra-radiculares fundidos obtidos de padrões de fundição modelados com a resina DuraLay mostraram-se significativamente melhor adaptados (42,31 µm ± 9,54 µm) quando comparados aos retentores intra-radiculares fundidos obtidos de padrões das resinas Pattern Resin (73,25 µm ± 32,86 µm) e Cop Clas (95,32 µm ± 45,02 µm) respectivamente; (2) Não houve diferença estatisticamente significante (p=0,273) na diferença média das fendas marginais dos retentores intra-radiculares fundidos modelados com a resina Pattern Resin e modelados com a resina Cop Clas (22,07 µm ± 13,13 µm). / Endodontically treated teeth are often mutilated by caries and access requirements. The remaining structure requires special treatment to prevent further destruction. When a large portion of the clinical crown has been lost, it is often impossible to achieve sufficient anchorage of a restoration in the remaining dentin. In such situations, a root-canal-retained restoration is required. Only the root portion can offer the needed retention for a functional and esthetic artificial crown. Different approaches can be taken to the fabrication of cast posts and cores. In this study, direct method was chosen to fashion it, by auto polymerizing acrylic resin. We used six standard metal patterns that simulate an anterior tooth prepared to receive cast post and core. Burn-out plastic patterns were fitted into the root canal and, using a fine sable hair brush, the polymer was introduced to fill the canal. After polymerization of the post, additional auto -polymerizing acrylic resin was added to form the core portion. This process can be repeated and correct if necessary. The acrylic resin patterns were then invested and casting was performed using nickel-chromium alloy. The cast was removed from investment. Cleaning was performed exclusively to remove the small positive nodules on the metal post and sandblast surface. The aim of this research was to compare the marginal fit of 54 cast posts constructed with three auto -polymerizing acrylic resins: 18 of DuraLay (Reliance Dental MFG Co., USA); 18 of Pattern Resin (GC Products, Japan); 18 of Cop Clas (Artigos Odontológicos Clássico Ltda., Brasil). The posts and cores were seated over the six standard metal patterns. Marginal discrepancies were bserved in scanning electron microscope (SEM). The measurements were registered and statistically analyzed. The results obtained showed that: (1) The cast post and core obtainedfrom DuraLay (42,31 µm ± 9,54 µm) had significant best fit than the cast post and core obtained from the others acrylic resins, Pattern Resin (73,25 µm ± 32,86 µm) and Cop Clas (95,32 µm ± 45,02 µm) respectively; (2) No significant statistic difference occur p=0,273) in the average marginal gap between the cast posts and cores obtained from Pattern Resin and Cop Class (22,07 µm ± 13,13 µm).
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Estudo in vitro da adaptação de retentores intra-radiculares fundidos, modelados com diferentes resinas acrílicas autopolimerizáveis / In vitro study of the fit of cast post and core, obtained from different acrylic resin patternsDenise Galhardo Rennó 21 September 2005 (has links)
Dentes tratados endodonticamente se encontram freqüentemente mutilados por cárie ou pelo próprio acesso ao canal. A estrutura dental remanescente necessita de tratamento especial para prevenir futuras fraturas. Quando uma grande parte da coroa dental foi perdida, é comum não haver retenção para a restauração na dentina remanescente. Nestas situações, uma restauração com retenção intracanal se faz necessária. Apenas a porção radicular pode oferecer a retenção apropriada para a instalação de uma coroa artificial estética e funcional. Diferentes técnicas podem ser usadas para a fabricação do retentor intra-radicular fundido. Neste estudo, foi escolhida a técnica direta para a confecção dos padrões de fundição em resina acrílica autopolimerizável. Usamos seis padrões metálicos com dimensões que simulavam dentes anteriores preparados para receber um retentor intra-radicular. Os condutos foram preenchidos com resina acrílica, usando um pincel bem fino, e pinos plásticos foram inseridos no interior dos canais. Após a polimerização do pino, adicionamos novas porções de resina acrílica para confecção das partes correspondentes aos núcleos. Essa técnica permite a correção de eventuais falhas, caso haja necessidade. Os padrões de fundição foram então incluídos em material de revestimento e fundidos em liga de níquel-cromo. O retentor intra-radicular fundido foi removido do revestimento e limpo. Apenas removemos os nódulos da superfície do metal, a qual recebeu, posteriormente, jateamento com óxido de alumínio. O objetivo deste estudo foi comparar a adaptação marginal de 54 retentores intra-radiculares fundidos, modelados com três resinas acrílicas autopolimerizáveis diferentes: 18 em DuraLay (Reliance Dental MFG Co., USA); 18 em Pattern Resin (GC Products, Japan); 18 em Cop Clas (Artigos Odontológicos Clássico Ltda., Brasil). Os retentores intra-radiculares fundidos foram assentados sobre os seis padrões metálicos. As fendas marginais foram observadas em microscópio eletrônico de varredura (MEV). As medições foram registradas e submetidas à análise estatística. Os resultados obtidos mostraram que: (1) Os retentores intra-radiculares fundidos obtidos de padrões de fundição modelados com a resina DuraLay mostraram-se significativamente melhor adaptados (42,31 µm ± 9,54 µm) quando comparados aos retentores intra-radiculares fundidos obtidos de padrões das resinas Pattern Resin (73,25 µm ± 32,86 µm) e Cop Clas (95,32 µm ± 45,02 µm) respectivamente; (2) Não houve diferença estatisticamente significante (p=0,273) na diferença média das fendas marginais dos retentores intra-radiculares fundidos modelados com a resina Pattern Resin e modelados com a resina Cop Clas (22,07 µm ± 13,13 µm). / Endodontically treated teeth are often mutilated by caries and access requirements. The remaining structure requires special treatment to prevent further destruction. When a large portion of the clinical crown has been lost, it is often impossible to achieve sufficient anchorage of a restoration in the remaining dentin. In such situations, a root-canal-retained restoration is required. Only the root portion can offer the needed retention for a functional and esthetic artificial crown. Different approaches can be taken to the fabrication of cast posts and cores. In this study, direct method was chosen to fashion it, by auto polymerizing acrylic resin. We used six standard metal patterns that simulate an anterior tooth prepared to receive cast post and core. Burn-out plastic patterns were fitted into the root canal and, using a fine sable hair brush, the polymer was introduced to fill the canal. After polymerization of the post, additional auto -polymerizing acrylic resin was added to form the core portion. This process can be repeated and correct if necessary. The acrylic resin patterns were then invested and casting was performed using nickel-chromium alloy. The cast was removed from investment. Cleaning was performed exclusively to remove the small positive nodules on the metal post and sandblast surface. The aim of this research was to compare the marginal fit of 54 cast posts constructed with three auto -polymerizing acrylic resins: 18 of DuraLay (Reliance Dental MFG Co., USA); 18 of Pattern Resin (GC Products, Japan); 18 of Cop Clas (Artigos Odontológicos Clássico Ltda., Brasil). The posts and cores were seated over the six standard metal patterns. Marginal discrepancies were bserved in scanning electron microscope (SEM). The measurements were registered and statistically analyzed. The results obtained showed that: (1) The cast post and core obtainedfrom DuraLay (42,31 µm ± 9,54 µm) had significant best fit than the cast post and core obtained from the others acrylic resins, Pattern Resin (73,25 µm ± 32,86 µm) and Cop Clas (95,32 µm ± 45,02 µm) respectively; (2) No significant statistic difference occur p=0,273) in the average marginal gap between the cast posts and cores obtained from Pattern Resin and Cop Class (22,07 µm ± 13,13 µm).
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Amélioration du ciment acrylique osseux utilisé lors de vertébroplasties / Enhancement of acrylic bone cement in vertebroplastyAhmari, Ali January 2010 (has links)
Vertebroplasty is a new technique in orthopedic surgery for stabilizing fractured vertebra. In this technique acrylic bone cement as a biocompatible material is injected through a cannula inside of vertebra. There are several concerns in this technique that the most serious one is cement leakage out of vertebra. The main reasons are improper viscosity and lack of visibility. Clinicians who practice vertebroplasty use commercial highly concentrated radiopaque acrylic bone cement (more than 25%BaSO[subscript 4] or ZrO[subscript 2]) or a cement with manually added radiopaque agents. High density materials with attenuation under X-ray are good alternatives compared to conventional radiopaque agents (BaSO[subscript 4] or ZrO[subscript 2]) in acrylic bone cement for application in vertebroplasty. In the first part of this study, thermal and rheological properties of modified acrylic bone cement with conventional radiopaque agent (Barium Sulfate, BaSO[subscript 4]) are studied. Additions of barium sulfate are in the form of substitute or excess. In substitute formulation, barium sulfate is replaced with the same weight of powder and liquid to powder ratio kept constant. In the excess formulation, barium sulfate added as excess and liquid to powder ratio decreased. In the second part of this study, high density radiopaque agents are used as alternative radiopacifier. Experimental design technique is used to study the effect of X-ray conditions, concentration, type, and size of radiopaque agents on the visibility of bone cement. The visibility of bone cement was quantified by the measurement of contrast index. In the first project, it was found that the setting time increased with the increase of concentration of radiopacifier in substitute formulation of barium sulfate bone cement. With increase of barium sulfate concentration, excess formulations showed higher residual monomer but for substitute cement, we had a decreasing trend. Acrylic bone cements with excess formulation had higher initial viscosity compared to reference or substitute but the variation of viscosity with time was lower for substitute formulation and cements had higher working time. In the second project, contrast index was the same for barium sulfate, tungsten, and zirconium in the lower voltage but in higher voltage of X-ray lamp, tungsten and zirconium gave higher contrast index. Variation of current in X-ray lamp changed the contrast index of cement slightly compared to the effect of voltage. Bone cement with nano tungsten had higher contrast index compared to the cement with micro size tungsten although micro size zirconium as radiopacifier gave higher contrast index than nano size zirconium.
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Using eggshell for the development of a quality alternative material to pumice in reducing the surface roughness of heat-cured acrylic resins.Onwubu, Stanley Chibuzor January 2016 (has links)
Submitted in fulfillment of requirements of the degree of Master in Health Sciences: Dental Technology, Durban University of Technology, Durban, South Africa, 2016. / Pumice is used in the polishing of dental appliances to remove surface irregularities. It is usually used in a slurry form that is pumice powder mixed with water. In Nigeria, the increased cost of pumice as a result of its limited supply into the country has encouraged dental technicians to re-use pumice slurry for longer periods than advocated when polishing acrylic dentures, whether new or old dentures which have been worn in the mouth. Consequently, this is likely to increase cross-infection of communicable diseases in the dental technology laboratory. Although materials such as white sand, black sand and porcelnite can be used, literature documents that these materials are less effective in the polishing of acrylic dentures (Areeg 2011). The focus of this study was to use eggshells, a natural waste product, to develop and test the quality of an alternative material to reduce the surface roughness of heat-cured acrylic resins.
A quantitative research paradigm and an experimental research strategy were adopted. The research design included two phases. In phase one of this study, different characterisation techniques such as Brunnae-Emmer Teller (BET); Fourier Transform Infrared Spectroscopy (FTIR); X-ray Diffraction (XRD); Energy Dispersive X-ray Spectroscopy (EDX) and Scanning Electron Microscope (SEM); Transmission Electron Microscopy (TEM); Laser Scattering Particle Size Distribution Analyser (PSA); Thermo-Gravimetric Analysis (TGA); and Induction-Coupling-Optical Emission Spectroscopy (ICP-OES) were used to assess the suitability of the new abrasive material (NAM). In addition, the level of microbial contamination of the NAM was assessed in line with the specified microbial limits for cosmetic products. In contrast, phase two investigated the product-based quality of the NAM as an abrasive material for removable dental appliances. There were two sample groups, that is, the NAM (test group) and Pumice (control), and each sample group had 50 PMMA acrylic specimens. The surface roughness (Ra) was measured using a Talysurf profilometer. An Independent Tukey test was used to analyse the Ra values (p=0.05). A Scanning Electron Microscope (SEM) and Optical Microscope (OEM) were further used to support the results of the profilometer in terms of the quality of surface finish and polish. Validity of the study was achieved following the ISO 20795-1 (2013) methods of preparation and fabrication of the acrylic specimens. The reliability was determined via reproducibility and repeatability of tests.
The BET analysis showed that the NAM is predominantly a mesoporous powder. The FTIR and XRD analyses confirmed that the NAM is pure calcite with unique water absorbing characteristics, and is free of bacteria. The EDX and ICP-OES analyses revealed calcium, oxygen and carbon as the major elemental composition of the NAM. The SEM and TEM images revealed irregular shaped particles in the NAM. The PSA analysis of the particle distribution showed the NAM to be superfine (50nm to 0.3µm) and medium (44µm powder), respectively. The TGA analysis revealed a high-grade carbonate product in the NAM (>66.0 mass% of calcium carbonates). In addition, and in terms of in the qualities of the NAM in reducing the surface roughness of PMMA resins, the test group and the control group produced Ra values that were significant different (p<0.0001). The SEM and OEM analyses further confirmed the differences in the surfaces between the polished sample groups at different magnifications. Overall, the control showed the highest mean average (0.1056±0.03688µm), whereas the test group had the lowest Ra values (0.0476±0.01379).
The lowest Ra values measured with the test group indicated that the NAM improves the surface smoothness of PMMA acrylic specimens. Notably, this study conclusively showed that the NAM effectively reduces the surface roughness to below the threshold limit value of 0.2µm. Significantly, and in associating the Ra values to the threshold limit value of 0.2µm, the NAM produced better results than pumice. Hence the use of the NAM as a polishing material for acrylic dentures is highly recommended. Finally and in line the NAM being a suitable alternative to pumice as it effectively reduces the surface roughness of PMMA specimens, future investigation into the use of eggshell nanoparticles to develop dental prophylaxes will be encouraged. / M
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Kick MeStackpole, Jennifer 01 January 2006 (has links)
Human experience, particularly the trials and tribulations of growing up, is the foundation on which I build. In this body of work, I represent these somewhat unsettling times. I use flattened space, strong diagonals, and vibrant color to add energy to the compositions. An underlying structure of fragmented shapes suggests the incomplete nature of adolescence.
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Objects and ImagesMagneson, Mary Bergshneider 01 January 2005 (has links)
I create to emphasize the aesthetic or beauty of an object. When I begin a work, I feel the influence of the many photos I am constantly looking at and analyzing. I look at how light affects color, how light defines form, and how patterns are created by repeated shapes. I try to reproduce the things I see, but with dramatic impact by enlarging shapes and emphasizing colors. While my paintings are about pure aesthetics, my books are social commentary.
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Creative MatrixMcGinn, Bonnie Gay 01 January 2007 (has links)
My personal life experiences are reflected in my art. I use symbolic and expressive marks in developing my abstract imagery, which acts as a visual language. The combining of my past and current art work, fused together, has become what I call a creative matrix. I see my images as choreographed compositions using a mixed media approach. The open-ended interpretation of my art have expanded the never ending possibilities of creation.
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NEJEN MOdŘE / Not Only BlueNovotná, Daria January 2012 (has links)
9 paintings, oil on canvas or acrylic on canvas - pictures from the sea, beach, wharf and their surroundings during the tourist season - aspects connected with the tourism at the sea - a little bit of romantic up to the border of the irony and kitch, business - processing of the water surface, their colours and shapes, real or seemingly abstract - shifting of the motif or his fragment through the form and colour reduction to the abstract line
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Comparison of The Fracture Resistance of Metal Reinforced Acrylic vs. Acrylic Only Distal Extension Cantilevers of Fixed Implant Supported ProsthesesOsswald, Martin Alexander 01 November 2006 (has links)
Student Number : 8701355N -
MDent research report -
School of Oral Health Sciences -
Faculty of Health Sciences / Purpose: The aim of this research project was to determine the fracture resistance to
linear vertical compressive forces of acrylic and metal-reinforced acrylic fixed
implant supported prosthesis cantilever arms. Methods: Ten non-reinforced and 10
reinforced acrylic superstructures were secured on five evenly distributed implants
and subjected to linear axial compressive forces utilising an Instron® materials testing
machine. The reinforcement consisted of commercially available preformed titanium
metal strengthener bars. Force was applied to the cantilever arms 15mm distal to the
distal most implant and two tests were conducted on each sample. The first drop in
load recorded was noted as a fracture of the sample. Results: Fracture of the acrylic
was noted at the distal most implant in both non-reinforced and the reinforced
samples. The mean fracture value for the non-reinforced samples was 679N and for
the reinforced samples, 628N. Conclusion: No significant difference between the
fracture resistance of the two designs was noted.
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