Dissertations / Theses: 'Denture Base Material'

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Cunningham, James Leo. "To develop a standard processing technique in order to maximise the bond strength between acrylic resin denture base material and polymer teeth." Thesis, Queen's University Belfast, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359018.

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Wieckiewicz, Mieszko, Volker Opitz, Gert Richter, and Klaus W. Böning. "Physical Properties of Polyamide-12 versus PMMA Denture Base Material." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-147158.

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Objectives. Polyamide-12 (PA) is a flexible material suited for denture bases and clasping. This study investigated its potential aging effects with a focus on surface roughness, color stability, and elasticity. Methods. PA specimens (Valplast) of 40 × 10 × 2mm and equally measuring PMMA specimens (Palapress) as control were fabricated. Color changes after storage in air, water, coffee, and red wine (n = 10) were measured using the CIE L*a*b color specification. Elasticity after thermocycling (1000, 3000, and 7000 cycles, n = 15) was measured by three-point bending testing. Mean surface roughness (Ra) was determined after storage in the liquids mentioned above and thermocycling (n = 10). Results. Tukey’s HSD test (P < 0.05) revealed statistically significant color changes of PA in red wine (ΔE = 4.27 after 12 days, EΔE = 6.90 after 12 days) and coffee (ΔE = 3.93 after 36 days) but no color changes in PMMA. Elastic modulus of PA was 845MPa and not affected by thermocycling (Tukey’s HSD test, P > 0.81). Dry specimens showed significantly decreased elasticity (P < 0.001). Mean surface roughness (PA 0.20 μm, PMMA 0.28 μm) did not change significantly after thermocycling or storage (Mann-Whitney U-test, 0.16 < P < 0.65). Significance. PA exhibited a higher susceptibility to discoloration than PMMA. Neither surface roughness nor elasticity of PA was altered by artificial aging.

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Jagger, Daryll. "A study into the reinforcement of poly (methyl methacrylate) denture base material." Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310639.

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Hotta, Juliana. "Biocompatibilidade in vivo de material resiliente temporário para base de prótese modificado por antimicrobianos para tratamento da estomatite protética." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/25/25146/tde-04052017-181513/.

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Reembasadores resilientes temporários contendo fármacos antifúngicos foram sugeridos como um tratamento adjunto para estomatite protética. No entanto, antes de utilizar clinicamente estes reembasadores modificados em humanos, é importante avaliar a sua biocompatibilidade em modelos animais. Este estudo avaliou a biocompatibilidade in vivo de um reembasador resiliente temporário para base de prótese (Trusoft) modificado por agentes antimicrobianos em suas mínimas concentrações inibitórias (MCIs) para biofilme de Candida albicans. Dispositivos acrílicos intra-orais (DIOs) foram confeccionados individualmente para 60 ratos Wistar. Os ratos foram divididos em 6 grupos (n=5): 3 grupos controle (Negativo: sem DIO; Geral: DIO sem reembasamento; Positivo: DIO reembasado com Trusoft sem fármacos) e 3 grupos experimentais (DIOs reembasados com Trusoft modificados por fármacos em suas respectivas MCIs: 0,032 g de nistatina, 0,064 g de diacetato de clorexidina e 0,128 g de cetoconazol). Os ratos com ou sem os DIOs foram eutanasiados após 7 e 14 dias de avaliação. A análise histopatológica qualitativa foi realizada comparando-se fotomicrografias de secções histológicas, que foram obtidas utilizando um microscópio óptico que abrangeu transversalmente a região intermolares. As alterações morfológicas no epitélio e queratina foram analisadas quantitativamente através da realização de planimetria computadorizada. Os dados quantitativos foram analisados utilizando ANOVA 2-fatores e teste de Tukey (=0,05). A análise quantitativa mostrou que apenas o grupo com DIO contendo cetoconazol diminuiu significativamente a espessura e a área do estrato córneo em comparação com os outros grupos (p<0,05), que não apresentaram diferenças significativas entre si (p>0,05). Estes resultados estiveram de acordo com os obtidos para análise qualitativa. A incorporação de MCIs de nistatina e diacetato de clorexidina no Trusoft não induziram alterações histopatológicas na mucosa palatina de ratos, sugerindo a biocompatibilidade in vivo deste protocolo para o tratamento de estomatite protética. Temporary resilient denture liners containing antifungal drugs have been suggested as an adjunct treatment for denture stomatitis. However, before clinically using these modified liners in humans, it is important to assess their biocompatibility in animal models. This study evaluated the in vivo biocompatibility of a temporary soft denture liner (Trusoft) modified by antimicrobial agents at their minimum inhibitory concentrations (MICs) for biofilm formation by Candida albicans. Methods: Acrylic intraoral devices (IODs) were individually made for 60 Wistar rats. The rats were divided into the following 6 groups (n=5): 3 control groups (Negative: without IOD; General: IOD without relining; Positive: IOD relined with Trusoft without drugs) and 3 experimental groups (IOD relined with Trusoft modified by drugs at MICs: 0.032 g for nystatin, 0.064 g for chlorhexidine diacetate, and 0.128 g for ketoconazole). The rats with or without the IODs were sacrificed after 7 or 14 days of evaluation. Histopathological qualitative analysis was performed by comparing photomicrographs of histological sections, which were obtained using an optical microscope that transversely covered the inter-molar region. Morphological changes in the epithelium and keratin were quantitatively analyzed by performing computerized planimetry. Quantitative data were analyzed using 2-way ANOVA and Tukey\'s test (=0.05). Quantitative analysis showed that only the group with IOD containing ketoconazole significantly decreased the thickness and area of the stratum corneum compared with the other groups (p<0.05), which showed no significant differences between each other (p>0.05). These results were in accordance with those obtained for qualitative analysis. Incorporation of MICs of nystatin and chlorhexidine diacetate in Trusoft did not induce histopathological changes in the palatal mucosa of rats, suggesting the in vivo biocompatibility of this protocol for treating denture stomatitis.

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龍英奇 and Ying-kei Christie Lung. "Residual monomer in denture base acrylic." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B42577743.

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Lung, Ying-kei Christie. "Residual monomer in denture base acrylic." Click to view the E-thesis via HKUTO, 2003. http://sunzi.lib.hku.hk/hkuto/record/B42577743.

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Tieng, Chhnoeum Nitipun Jeeraphaet. "Effect of denture cleanser on the surface roughness and hardness of denture base materials /." Abstract Full Text (Mahidol member only), 2008. http://10.24.101.3/e-thesis/2551/cd424/4937437.pdf.

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Latief, Abduraghman. "Sorption and solubility of a denture base acrylic." Thesis, Cape Peninsula University of Technology, 2012. http://hdl.handle.net/20.500.11838/1533.

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Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Dental Technology in the Faculty of Health and Wellness Sciences at the Cape Peninsula University of Technology, 2012 Statement of problem It is well documented that water sorption and water solubility by auto-polymerizing resins have a negative impact on their physical properties and may lead to harmful tissue reactions. The presence of residual monomer is often identified as the main cause for adverse tissue reactions. To optimize the polymerization reaction, the use of the proper powder/liquid ratio is recommended in the fabrication of a dental appliance. It is also recommended that a dental appliance should be soaked in water for at least 24 hours before delivery to a patient, in order to reduce the possible adverse effect. For auto-polymerizing resins, associated with higher residual monomer levels than heat-cured resins, soaking the appliance at elevated temperatures (65ºC for 60 minutes), would reduce the residual monomer content more efficiently than at room temperature. This requires additional processing conditions from the technician or dentist. Changing the powder/liquid ratios, deliberately or not, may modify the residual monomer content of the final product. A relationship exists between the levels of residual monomer and water sorption. Also, residual monomer leaching into the oral fluids may lead to adverse effects such as, oral tissue irritation or a delayed hypersensitivity reaction. Aim of the study The aim of this study was to evaluate the effect of different powder/liquid ratios and different water temperatures on the levels of sorption and solubility of an auto-polymerizing resin material used for denture bases. The null-hypothesis tested was that there is no difference in sorption and solubility among groups of specimens made from an auto-polymerizing resin material soaked in water at different temperatures and/or fabricated with different powder/liquid ratios. Material and methods Specimens were made from cold-cure pour-type denture base resin (Type 2, Class 2) using different powder/liquid ratios and soaked at different soaking temperatures. One group of specimens fabricated with the manufacturer’s recommended powder/liquid ratio and soaked in water at 37ºC, served as the control group for both experiments. Custom-made stainless steel moulds were used to fabricate resin disks, with a diameter of 50mm and a thickness of 0.5mm. For the temperature-controlled experiment, identical specimens were prepared and stored in distilled water at 37ºC; 45ºC; 55ºC and 67ºC. For the ratio-controlled experiment, the ratios were increased incrementally for each group, starting with a 10% increase, followed by a 15%; 20% and 25% increase in monomer. Water sorption and solubility were tested in accordance with ISO Standard 1567 (1999). Specimens were weighed before and after water immersion, and desiccation. Water sorption and solubility were calculated using the difference in wet and dry mass and the volume of the specimens. The water sorption and solubility results were analyzed by means of analysis of variance. For multiple comparisons, Bonferroni simultaneous confidence intervals (α=0.05) were applied. Results For the ratio-controlled experiment, water sorption mean values varied from 24.148 μg/mm3 to 25.1333 μg/mm3. Statistically significant differences in mean values were found between the following groups: 0%-10%; 0%-15%; 0%-25%; 10%-20%; 15%-20% and 20%-25% ratio groups (P<.0001). Water solubility mean values varied from 0.616μg/mm3 to 0.932μg/mm3. Statistically significant differences in mean values were found between the following groups: 0%-15%; 0%-20%; 0%-25% and 10%-25% and 20%-25% ratio groups (P<.0001). For the temperature-controlled experiment, water sorption mean values varied from 24.185μg/mm3 to 26.434μg/mm3. Statistically significant differences in mean values were found between the following groups: 37ºC-45ºC; 37ºC-55ºC; 37ºC-67ºC; 45ºC-67ºC and 55ºC-67ºC temperature-controlled experiments (P<.0001). Water solubility mean values, for the same experimental groups, varied from 0.616μg/mm3 to 2.752μg/mm3. Statistically significant differences in mean values were found among all the 6 pairs of groups (P<.0001). Despite statistical differences, the water sorption and water solubility values of the tested resin for both experiments and all groups were within the ISO Standard 1567 (1999) specification limits. Conclusion For the ratio-controlled experiment, there was an inverse relationship between the mean sorption and solubility values with an increase in liquid in the mixture: low water sorption levels are associated with high solubility levels. The lower water sorption and higher solubility results for more fluid mixtures could be related to initial and residual high monomer content characteristic of auto-polymerizing materials. These higher levels of free monomer are consequently released upon immersion in water; hence the higher water solubility levels. For the temperature-controlled experiment, a higher soaking temperature resulted in an increase in water solubility levels. The higher solubility levels could be attributed to the higher soaking temperatures causing higher or faster monomer diffusion from the resin material. Except for the 67ºC group, sorption is also lower with higher temperatures. It may be assumed that an additional polymerization process takes place and a subsequent more inaccessible polymer matrix is produced. For the 67ºC group, thermal expansion may explain the higher sorption level. Clinical Implications In terms of the sorption and solubility results, this auto-polymerizing pour-type resin may be used as a denture base resin. Even though statistical differences were demonstrated, the material satisfies the ISO 1567 (1999) requirements not only for auto-polymerizing but also for heat-polymerizing resins. Therefore, within limits, the mixture may be prepared more fluidly in order to improve flow of the material, without negatively affecting its sorption and solubility properties. Because solubility is higher at higher soaking temperatures, this property can be used to minimize monomer content of the appliance. Therefore, it is recommended that the dental appliance be soaked in warm water, below 67ºC, prior to delivery to the patient.

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Tarigan, Slamat. "The assessment of bonding between synthetic tooth materials and denture base resins." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329067.

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Van, Der Poel Nadine Olive. "Mechanical retention of acrylic teeth onto a pure nylon base." Thesis, Cape Peninsula University of Technology, 2014. http://hdl.handle.net/20.500.11838/1536.

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Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Dental Technology in the Faculty of Health and Wellness Sciences at the Cape Peninsula University of Technology 2014 A pure nylon denture base does not bond chemically to the acrylic teeth processed into the denture. A mechanical bond is created by boring retention holes (diatorics) into the tooth structure. Concerns are that this form of retention might be insufficient. The purpose of this study is, firstly, to compare the retention of acrylic denture teeth in pure nylon dentures with that of teeth in conventional acrylic denture bases (the acrylic test pieces serving as the control standard), and secondly, to explore whether the technique prescribed for creating diatorics in acrylic teeth for use with pure nylon denture bases potentially has a weakening effect on the acrylic tooth structure. Two sets of 26 identical anterior one-tooth test pieces were created. The first set, labelled N, comprises two different pure nylon denture base materials labelled N1 and N2 – all have diatorics in the acrylic teeth. The second set, labelled A, comprised the same acrylic denture base. The set labelled A1 is the control standard without diatorics in the acrylic teeth and the set labelled A2 has diatorics within the acrylic teeth. A compressive load was applied to these test pieces at an angle of 45 degrees on the palatal surface of the tooth until fracture occurred or maximum load was reached. Resulting data from the first part of the research was analysed by One-Way ANOVA analysis. Resulting data for the second part of the research was analysed via the Chi-square cross- tabulation method. The One-Way ANOVA test revealed that there is no statistical difference in the mean fracture or maximum load in Newton values between the two A (acrylic denture base) groups. There is also no statistical difference in the mean fracture or maximum load in Newton values between the two N (pure nylon denture base) groups. There is, however, a statistically significant difference in the mean fracture or maximum load in Newton values of Group A in comparison to Group N. The Chi-square cross-tabulation indicated that the A groups have very similar breakage patterns, and the N groups have similar breakage patterns respectively. It is concluded that the mechanical retention of acrylic denture teeth in pure nylon denture bases is weaker than the mechanical and chemical retention of acrylic denture teeth in acrylic denture bases. It is also concluded that when diatorics are created as prescribed within the tooth, these do not weaken the tooth structure.

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Ironside, James G. "An in vitro analysis of the behaviour of an alumina based dental all-ceramic restorative system subjected to occlusal loads." University of Sydney, 2001. http://hdl.handle.net/2123/4254.

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Doctor of Philosophy The commercial introduction of glass infiltrated slip cast ceramic technology as a core dental ceramic for crowns and bridges began in 1990. The system known as Inceram® provided a metal free ceramic core with a flexural strength that was reported to be between 400 and 600 MPa. The first aim of this study was to investigate in vitro fractures for this type of crown that occurred from high localized occlusal loading. The second aim was to propose suitable guidelines for the construction of crowns that are more crack resistant when loaded by a spherical object such as an opposinc cusp. The review of the literature identified Young’s modulus (E) as an important aspect for the behaviour of a brittle solid when it is exposed to load. Young’s modulus is involved in the total energy of the solid, its free surface energy, its toughness, parameters involved in contact areas, stresses from indenters on those contact areas and at the interface between two materials with different moduli. This mismatch was to become more important when Finite Element Analysis was applied to the test results. A second physical property that has importance in bilaminar minerals is Poisson’s ratio. Less important than Young’s modulus, Poisson’s ratio still provides some of the answers to crack propagation at an interface, highlighted by the description of Dundurs parameters (Mencik 1996). The use of Weibull statistics provided information concerning reliability for different core to veneer thickness ratios in the experimental models and crown designs. The first experimental part was to establish a crown model suitable for investigation. The porcelain jacked crown restoration for an upper incisor was chosen because it provided the best opportunity to vary the construction parameters of the crown without sacrificing the aesthetics. The results from this initial in vitro study established thickness ranges for the standard design of these crowns, the loads that could be expected and the two types of fracture patterns that might occur when the bilaminar system is loaded via a hard steel ball indenter in the middle of the palatal surface. The data from chapter three were then compared with two basic bilaminar and monolithic disc designs to establish the relevance of the dimensions of the ISO standard test specimen design for flexural strength. The results of this chapter confirmed that the loads were in the same range for the bilaminate discs, and that the flexural strengths for the two component parts were in agreement with other known results. The use of Finite Element Analysis (FEA) was employed to provide an additional method for testing the model to establish areas when principal stresses might lie and how they were distributed. It was found that the ISO flexural strength test was not ideal for testing bilaminates because it did not account for the large mismatch in Young’s modulus between the two component materials. The FEA revealed an unexpected increase in tensile stress on the bottom surface of the In-Ceram when it was the bottom layer in the bilaminate. The FEA did confirm the difference between a flat punch and a ball indenter for stress intensities around the contact area with the ball indenter producing higher stresses for a given load…

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Lima, Jozely Francisca Mello. "Efeito da incorporação de agentes antimicrobianos sobre propriedades físicas de materiais resilientes temporários para base de prótese." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/25/25146/tde-23042014-104629/.

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O objetivo do presente estudo foi avaliar o efeito da adição de mínimas concentrações inibitórias (MCIs) de agentes antimicrobianos para biofilme de Candida albicans na sorção de água e solubilidade de materiais resilientes temporários (Softone e Trusoft) para reembasamento de próteses removíveis. Os grupos de estudo (n=10) foram formados por corpos de prova circulares (50 mm x 0,5 mm) dos materiais sem (controle) ou com a incorporação das MCIs de três fármacos utilizados para tratamento de estomatite protética: nistatina (Ni)-0,032g/mL; diacetato de clorexidina (Cl)- 0,064g/mL; cetoconazol (Ce)- 0,128g/mL. Para determinar a sorção de água e solubilidade, as amostras foram dessecadas, imersas em água por 24 h, 7 ou 14 dias, pesadas, dessecadas e pesadas novamente. Os dados obtidos (μg/mm3) foram analisados por ANOVA 3 fatores e teste de Tukey (α=0,05). Comparado aos respectivos controles, a sorção de água dos dois materiais avaliados aumentou com a adição de nistatina e clorexidina após 24 h e 7 dias de imersão em água (P<0,0001). Após 14 dias de avaliação, exceto pela clorexidina (P<0,0001) no Softone (483,00 ± 61,00 μg/mm3), a sorção dos materiais não foi afetada (P>0,05) pela adição dos fármacos (Softone: Ni- 310,72 ± 55,00 μg/mm3; Ce- 202,13 ± 52,28 μg/mm3/ Trusoft: Ni- 320,26 ± 22,89 μg/mm3; Ce: 300,45 ± 69,49 μg/mm3; Cl: 331,01 ± 48,18 μg/mm3) em comparação aos respectivos controles (Softone: 244,00 ± 42,00 μg/mm3; Trusoft: 274,85 ± 83,12 μg/mm3). Para todos os grupos, o tempo de imersão aumentou (P<0,0001) a solubilidade do Softone (24h: 18,82 ± 9,80 μg/mm3; 7d: 32,16 ± 4,48 μg/mm3; 14d: 58,81 ± 8,79 μg/mm3), mas não do Trusoft (24h: 12,46 ± 4,51 μg/mm3; 7d: 14,34 ± 5,20 μg/mm3; 14d: 15,48 ± 5,68 μg/mm3) (P>0,05). Em relação aos controles e para todos os períodos, a solubilidade dos dois materiais foi alterada com clorexidina e cetoconazol (P<0,0001), mas não sofreu influência da nistatina (P>0,05). Foi possível concluir após 14 dias de imersão em água, a adição das MCIs de nistatina e cetoconazol nos dois materiais resilientes e de clorexidina no Trusoft não interferiu com a sorção de água. A solubilidade dos dois materiais temporários testados não foi alterada pela nistatina em até 14 dias de avaliação. The objective of the present study was to evaluate the addition of minimum inhibitory concentrations (MICs) of antimicrobial agents for C. albicans biofilm on the water sorption and solubility of temporary resilient materials (Softone e Trusoft) for denture base relining. Test groups (n=10) were formed by disc specimens (50 mm x 0.5 mm) of the materials without (control) or with incorporation of the MICs of three drugs for denture stomatitis\' treatment: nystatin (Nt)- 0.032g/mL; chlorhexidine diacetate (Cl)- 0.064g/mL; ketoconazole (Kt)- 0.128g/mL. To determine the water sorption and solubility, samples were dried, immersed in water for 24 h, 7 or 14 days, weighed, dried and weighed again. Data (μg/mm3) were analyzed by 3-way ANOVA and Tukeys test (α=.05). Compared to the respective controls, the water sorption of the two materials evaluated increased with the addition of nystatin and ketoconazole after 24 h and 7 days of water immersion (P<.0001). After 14 days of evaluation, except by chlorhexidine (P<.0001) in Softone (483.00 ± 61.00 μg/mm3), the sorption of the materials was not affected (P>.05) by the addition of the drugs (Softone: Nt- 310.72 ± 55.00 μg/mm3; Kt- 202.13 ± 52.28 μg/mm3 / Trusoft: Nt- 320.26 ± 22.89 μg/mm3; Kt: 300.45 ± 69.49 μg/mm3; Cl: 300.45 ± 69.49 μg/mm3) compared to the respective controls (Softone: 244.00 ± 42.00 μg/mm3; Trusoft: 274.85 ± 83.12 μg/mm3). For all groups, the immersion time increased (P<.0001) the solubility of Softone (24h: 18.82 ± 9.80 μg/mm3; 7d: 32.16 ± 4.48 μg/mm3; 14d: 58.81 ± 8.79 μg/mm3), but not of Trusoft (24h: 12.46 ± 4.51 μg/mm3; 7d: 14.34 ± 5.20 μg/mm3; 14d: 15.48 ± 5.68 μg/mm3) (P>.05). In comparison to the controls, and for all periods the solubility of the both materials was affected with chlorhexidine and ketoconazole (P<.0001), but not was influenced by nystatin (P>.05). It can be concluded that after 14 days of water immersion the addition of MICs of nystatin and ketoconazole in the both resilient materials and chlorhexidine in the Trusoft did not affect the water sorption. The solubility of the two temporary materials tested was not altered by nystatin up to 14 days.

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Maciel, Janaina Gomes. "Padronização da metodologia para análise de sorção de água e solubilidade de materiais resilientes temporários para base de prótese." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/25/25146/tde-07112016-085937/.

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Não existem normas internacionais que determinem limites aceitáveis de sorção de água e solubilidade para os materiais resilientes temporários para base de prótese, além de haver divergências metodológicas nos estudos. Objetivou-se avaliar de forma padronizada essas propriedades físicas para materiais macios de curta duração ao longo de sua vida útil. Corpos de prova (50mm x 0,5mm/ ISO-10139-2) de 7 condicionadores teciduais (Coe-Comfort-CC, Softone-ST, Rite-Line-RL, Dura Conditioner-DC, Hydro-Cast-HC, DentusoftDS e Visco-gel-VG) e 2 reembasadores resilientes temporários (Trusoft-TS e Coe-Soft-CS) foram individualmente confeccionados e submetidos à dessorção até estabilização das massas. Então, foram imersos em água destilada a 37oC por 3, 5, 7 ou 14 dias (n=10) para depois serem pesados, dessecados e pesados novamente. Os dados foram obtidos em porcentagens de sorção/solubilidade e analisados estatisticamente por ANOVA 2 fatores e teste de Tukey HSD (α=0,05). Em todos os períodos, VG (12,06±0,93 a 16,62±0,87%) apresentou a maior sorção de água dentre os materiais testados, sendo as menores porcentagens observadas para CC (2,23±0,53 a 2,99±0,49%) (P<0,05). CC, CS e TS não apresentaram alteração significativa da sorção de água ao longo de 14 dias (P>0,05). Já os demais materiais exibiram um aumento significativo da sorção de água entre os períodos de 7 e 14 dias (P<0,05). Para a solubilidade, valores médios inferiores e estatisticamente semelhantes foram apresentados pelos materiais DC, HC, DS, TS, RT e CS (0,28±0,30 a 2,13±0,23%) (P>0,05). ST (4,09±1,60 a 8,80±1,15%) demonstrou maior solubilidade que CC (1,89±0,30 a 3,35±0,70%), mas os mais altos valores percentuais dentre os materiais testados foram observados para VG (20,30±4,26 a 23,59±20,24%) (P<0,05). CC, DC, DS, HC, RT, TS e CS não apresentaram alterações na solubilidade percentual média ao longo dos 14 dias de avaliação. Já os condicionadores teciduais VG e ST exibiram aumento dos valores médios apenas aos 14 dias de imersão em água. Conclui-se que, ao longo da vida útil média de um condicionador tecidual (7 dias), os materiais CC, DC, HC, DS, RL, CS e TS apresentaram comportamento in vitro satisfatório em relação à sorção de água e solubilidade. De acordo com os resultados obtidos, os materiais CC, TS e CS foram considerados os mais indicados dentre os testados para reembasamento de próteses em até 14 dias. There are no international standards that determine acceptable limits of water sorption and solubility for the temporary resilient liners, besides the differences in the methodology of the studies. It was aimed to evaluate in a standardized manner these physical properties of short-term soft materials throughout their lifespan. Specimens (50mm x 0.5mm/ ISO-10139-2) of 7 tissue conditioners (Coe-Comfort-CC, Softone- ST, Rite-Line-RL, Dura Conditioner-DC, Hydrocast-HC, Dentusoft-DS and Visco-gel- VG) and 2 temporary resilient liner (Trusoft-TS e Coe-Soft-CS) were individually prepared and submitted to desorption until mass stabilization. Afterwards, they were immersed in distilled water at 37oC for 3, 5, 7, or 14 days (n=10) to then be weighed, dried and reweighed. The data were obtained in percentages of sorption/solubility and statistically analyzed by 2-way ANOVA and Tukeys test (α=0.05). In all periods, VG (12.06±0.93 to 16.62±0.87%) showed the highest water sorption among the tested materials, with the lowest percentages observed for CC (2.23±0.53 to 2.99±0.49%) (P<0.05). CC, CS and TS showed no significant changes in water sorption over 14 days (P>0.05). The other materials exhibited a significant increase in water sorption between the periods of 7 and 14 days (P<0.05). For the solubility, lower (and statistically similar to each other) values were presented by DC, HC, DS, TS, RT, and CS materials (0.28±0.30 to 2.13±0.23%) (P>0.05). ST (4.09±1.60 to 8.80±1.15%) showed higher solubility than CC (1.89±0.30 to 3.35± 0,70%), but the highest percentages among tested materials were observed for VG (20.30±4.26 to 23.59±20.24%) (P<0.05). CC, DC, DS, HC, RT, TS, and CS showed no changes in the mean percentage solubility throughout the 14-day trial. The tissue conditioners VG and ST exhibited increased average values only at 14 days of water immersion. It was concluded that, over the lifespan of a tissue conditioner (7 days), the materials CC, DC, HC, DS, RL, CS, and TS presented suitable in vitro performance with respect to water sorption and solubility. According to the results, the materials CC, TS, and CS were considered best suited among the tested materials for denture relining of up to 14 days.

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Lima, Jozely Francisca Mello. "Efeito da incorporação de agentes antifúngicos na resistência à tração e porosidade de materiais resilientes temporários para base de próteses." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/25/25146/tde-30052017-212223/.

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Este estudo investigou a resistência à tração (ou limite de resistência à tração- LRT) e a porosidade de reembasadores resilientes temporários modificados por concentrações inibitórias mínimas (CIMs) de agentes antifúngicos para o biofilme Candida albicans (SC5314). Para os testes de LRT, corpos de prova em forma de halteres (n=7) com uma área transversal de 33 mm x 6 mm x 3 mm foram produzidos para os materiais resilientes (Trusoft e Softone) sem (controle) ou com incorporação de cinco fármacos em suas CIMs: nistatina- 0,032 g; diacetato de clorexidina- 0,064; cetoconazol- 0,128 g; miconazol- 0,256 g; itraconazol-0,256 g (grama de fármaco por grama de pó de material resiliente). Após a plastificação, as amostras foram imersas em água destilada a 37°C durante 24 h, 7 e 14 dias e, então, testadas em tensão em uma máquina universal de ensaios (EMIC DL-500 MF) a 40 mm/min. A porosidade foi mensurada por absorção de água, com base na exclusão do efeito plastificante. Inicialmente, determinou-se por isotermas de sorção, que a solução de armazenagem adequada para os corpos de prova (65 mm x 10 mm x 3,3 mm) de ambos os materiais foi o cloreto de cálcio anidro a 50% (S50). Assim, o fator de porosidade (FP) foi calculado para os grupos de estudo (n=10) formados por espécimes sem (controle) ou com incorporação de fármaco em suas CIMs (nistatina, clorexidina ou cetoconazol) após a armazenagem em água destilada ou S50 por 24 h, 7 e 14 dias. Os dados de resistência à tração (MPa) e percentagem de alongamento (%) foram submetidos à ANOVA de 3 fatores seguida pelo teste de Tukey (=0,05). Os dados de porosidade foram analisados estatisticamente por ANOVA de medidas repetidas para 4 fatores e teste de Tukey (=0,05). Ao final de 14 dias, a resistência à tração para ambos os materiais foi significativamente menor nos grupos modificados pelo miconazol e itraconazol em relação aos outros grupos (P<0,0001), que não mostraram diferenças significativas entre si (P>0,05). Após 7 e 14 dias em água, o miconazol e itraconazol adicionados a ambos os materiais resultaram em percentagens significativamente menores de alongamento em comparação com os outros fármacos e ao controle (P<0,0001), que foram semelhantes entre si (P>0,05). O cetoconazol não resultou em alterações significativas no FP para ambos os materiais resilientes em água ao longo de 14 dias (P>0,05). Em comparação aos controles, houve aumento dos FPs do Softone e Trusoft aos 14 dias de imersão em água somente após a adição de nistatina e clorexidina e de clorexidina, respectivamente (P<0,05). Ambos os materiais não apresentaram alterações significativas no FP em até 14 dias de imersão na S50, em comparação aos controles (P>0,05). Em todas as condições experimentais, os FPs do Softone e Trusoft foram significativamente menores quando imersos em S50 em comparação com a água destilada (P<0,05). Concluiu-se que a adição de nistatina, clorexidina e cetoconazol nas CIMs para o biofilme de C. albicans não resultou em efeitos deletérios na resistência à tração e na percentagem de alongamento dos materiais resilientes temporários para base de prótese até o período de 14 dias. A adição de antifúngicos nas CIMs não resultou em efeitos adversos à porosidade de ambos os materiais resilientes temporários em diferentes períodos de imersão em água, com exceção da clorexidina e nistatina no Softone e clorexidina no Trusoft aos 14 dias. Não foram observados efeitos deletérios para a porosidade de ambos os materiais resilientes modificados com as CIMs dos fármacos durante os 14 dias de imersão na S50. This study investigated the tensile strength (ultimate tensile strength- UTS) and porosity of temporary soft denture liners modified by minimum inhibitory concentrations (MICs) of antifungal agents for Candida albicans biofilm (SC5314). For UTS tests, dumbbell-shaped specimens (n=7) with a central cross-sectional area of 33 mm x 6 mm x 3 mm were produced by resilient materials (Trusoft and Softone) without (control) or with incorporation of five drugs at MICs: nystatin- 0.032 g; chlorhexidine diacetate-0.064 g; ketoconazole- 0.128 g; miconazole- 0.256 g; itraconazole- 0.256 g (each per gram of soft liner powder). After plasticization, specimens were immersed in distilled water at 37°C for 24 h, 7 and 14 days, and then tested in tension in a universal testing machine (EMIC DL-500 MF) at 40 mm/min. The porosity was measured by water absorption, based on exclusion of the plasticizer effect. Initially, it was determined by sorption isotherms that the adequate storage solution for specimens (65 mm x 10 mm x 3.3 mm) of both materials was 50% anhydrous calcium chloride (S50). Then, the porosity factor (PF) was calculated for the study groups (n=10) formed by specimens without (control) or with drug incorporation at MICs (nystatin, chlorhexidine or ketoconazole) after storage in distilled water or S50 for 24 h, 7 and 14 days. Data of tensile strength (MPa) and elongation percentage (%) were submitted to 3-way ANOVA followed by Tukey\'s test (=0.05). Data of porosity were statistically analyzed by 4-way repeated measures ANOVA and Tukeys test (=0.05). At the end of 14 days, the tensile strength for both materials was significantly lower in the groups modified by miconazole and itraconazole compared to the other groups (P<0.0001), which showed no significant difference between them (P>0.05). After 7 and 14 days in water, miconazole and itraconazole added into both materials result in significant lower elongation percentages compared to the other drugs and control (P<.0001), which were similar to each other (P>0.05). Ketoconazole resulted in no significant changes in PF for both liners in water over 14 days (P>0.05). Compared to the controls, Softone and Trusoft PFs were increased at 14-day water immersion only after addition of nystatin and chlorhexidine, and chlorhexidine, respectively (P<0.05). Both materials showed no significant changes in PF in up to 14 days of S50 immersion, compared to the controls (P>0.05). In all experimental conditions, Softone and Trusoft PFs were significantly lower when immersed in S50 compared to distilled water (P<0.05). It was concluded that the addition of the nystatin, chlorhexidine and ketoconazole at MICs for C. albicans biofilm resulted in no harmful effects on the ultimate tensile strength and elongation percentage of the temporary soft denture liners up to 14-day period. The addition of antifungals at MICs resulted in no detrimental effects for the porosity of both temporary soft liners in different periods of water immersion, except for chlorhexidine and nystatin in Softone and chlorhexidine in Trusoft at 14 days. No deleterious effect was observed for the porosity of both soft liners modified by the drugs at MICs over 14 days of S50 immersion.

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Radford, David Robert. "Adherence of #Candida albicans' to denture base materials : the effects of surface finish and dimorphic expression of phenotypically switched organisms." Thesis, King's College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307457.

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Atmeh, Amre. "Optical characterisation of the interaction between calcium-silicate based dental restorative materials and dentine." Thesis, King's College London (University of London), 2013. https://kclpure.kcl.ac.uk/portal/en/theses/optical-characterisation-of-the-interaction-between-calciumsilicate-based-dental-restorative-materials-and-dentine(8949ef19-09fc-4303-87be-c6a3835d21ea).html.

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Since their introduction to dentistry, calcium silicate based cements have been mainly used for endodontic applications, principally due to their long setting time. Recently, a new formulation of this cement was produced as a coronal restorative material. The aim of this project was to study the nature and dynamics of the interface between this calcium silicate based dental restorative material (BiodentineTM) with human dentine in comparison with glass ionomer cement, and to investigate its capability to induce dentine remineralisation. Different optical, microscopic, and fluorescent labelling techniques have been applied; such as tandem scanning and laser scanning confocal microscopy, which were both used with cement labelling and micropermeability tests to evaluate the interfacial morphology and microscopic appearance along with scanning electron microscopy. Additionally, two-photon fluorescence microscopy was applied in conjugation with Tetracycline labelling to study dentine remineralisation induced by the Biodentine cement; this novel combination provided a useful technique for the observation of mineral formation inside the organic matrix of demineralised dentine when aged in an in-vitro model. Fluorescence lifetime imaging and second harmonic generation imaging were also used for the characterisation of re-mineralisaion and collagen denaturation respectively. For the chemical analysis, Raman spectroscopy was applied to analyse the chemical composition of the cement and the changes associated with its hydration and ageing in different conditions. Micro-Raman imaging was also applied to quantify and model the infiltration of the cement’s hydration products into the dentine. Results indicated an interactive interface between the Biodentine and sound dentine, mediated by the alkaline caustic effect of the cement on the dentine’s organic component, which was associated with mineral transfer, and led to the formation of what we described as a “Mineral Infiltration zone” (MIZ). This later explained the ability of Biodentine to induce remineralisation of dentine and the formation of apatite structures, which indicated the bioactivity of the cement.

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Perez, Luciano Elias da Cruz [UNESP]. "Efeito de tratamentos da superfície de união e materiais reembasadores na resistência ao impacto de resina para base de prótese." Universidade Estadual Paulista (UNESP), 2005. http://hdl.handle.net/11449/97294.

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Made available in DSpace on 2014-06-11T19:28:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-03-04Bitstream added on 2014-06-13T19:58:17Z : No. of bitstreams: 1 perez_lec_me_arafo.pdf: 742869 bytes, checksum: 6a15f2294a9963313f8b26b36009e31b (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Este estudo avaliou o efeito de tratamentos da superfície de união e de materiais reembasadores na resistência ao impacto de uma resina para base de prótese. Corpos-de-prova foram confeccionados com a resina Lucitone 550 (60x6x2 mm) e reembasados (2 mm) com o mesmo material (L) ou com as resinas para reembasamento imediato Tokuso Rebase (TR) e Ufi Gel Hard (UH). Para o material L, as superfícies de união permaneceram sem tratamento (L/L/ST) ou foram tratadas com o monômero da resina L (metil metacrilato) for 180 segundos (L/L/M). Quando o reembasamento foi realizado com os reembasadores imediatos, os tratamentos de superfície consistiram de aplicação dos agentes adesivos fornecidos pelos fabricantes (L/TR/A - diclorometano e L/UH/A - diclorometano e 2-hidroxietil metacrilato) ou tratamento com o monômero da resina L seguido pelos adesivos (L/TR/MA e L/UH/MA). Corpos-de-prova do material L intacto (60x6x4 mm) também foram confeccionados para se determinar a resistência ao impacto dessa resina. Um total de 140 corpos-de-prova foi confeccionado, sendo 20 para cada condição experimental. Para metade dos corpos-de-prova, os entalhes foram realizados na largura, na superfície correspondente ao material reembasador, com profundidade de 0,8 mm, permanecendo 3,2 mm de material intacto (E1). Para os corpos-de-prova restantes, o entalhe foi realizado na espessura, envolvendo tanto o material reembasador como a resina de base, com profundidade de 1,2 mm (E2), permanecendo 4,8 mm de material intacto. Todos os entalhes, em forma de V, foram realizados na área central do comprimento dos corpos-de-prova. O teste utilizado foi do tipo Charpy, com pêndulo de 0,5 J e distância de 50 mm entre os suportes. Os resultados (kJ/ m2) de cada entalhe foram analisados, separadamente, utilizando-se ANOVA e teste de... This study evaluated the effect of surface treatments and reline materials on the impact strength of a denture base acrylic resin. Specimens were made using Lucitone 550 resin (60x6x2 mm) and relined (2 mm) with the same material (L) or with the hard chair-side reline resins Tokuso Rebase (TR) and Ufi Gel Hard (UH). For material L, the bond surfaces remained untreated (L/L/ST) or were wetted with resin L monomer (methyl methacrylate) for 180 seconds (L/L/M). When the relining was made with the hard reline materials, the surface treatments consisted of coating with the bonding agents supplied by the manufacturers (L/TR/A - dichloromethane and L/UH/A - dichloromethane and 2-hydroxyethyl methacrylate) or wetting with the resin L monomer followed by bonding agents application (L/TR/MA and L/UH/MA). Material L intact specimens (60x6x4 mm) were also made to determine the impact strength of the bulk resin. A total of 140 specimens were made, 20 for each experimental condition. Half of the specimens were notched across the width to a depth of 0.8 mm, leaving an effective depth under notch of 3.2 mm (E1). For the remaining specimens, the notch was cut across the thickness to a depth of 1.2 mm (E2) leaving an effective depth under notch of 4.8 mm. All the V-notches were machined at the midpoint of the length of the specimens. Impact tests were carried out on a Charpy type pendulum impact tester (0.5 J pendulum; distance between supporting points - 50 mm). Results (kJ/ m2) from each notch depth were analyzed separately using one-way ANOVA and Tukey's HSD tests (a = .05). No significant differences were noted among the mean impact values of L (1.39 kJ/ m2), L/L/ST (1.28 kJ/ m2) and L/L/M (1.20 kJ/ m2) specimens with the E1 notch (P>.05). Similar results were observed (P>.05) for the specimens with the E2 notch (L - 1.00 kJ/ m2; L/L/ST - 0.93 kJ/ m2; ...(Complete abstract, click electronic access below)

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Ozturk, Hale Bahar. "Mechanical And Thermal Properties Of Thermotropic Liquid Crystalline Copolyester (tlcp) And Its Mixtures With Poly(ethyleneterephthalate) And Denture Base Poly(methyl Methacrylate)." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605205/index.pdf.

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In this study, the thermal and mechanical properties of poly(ethylenetheraphthalate) (PET)-thermotropic liquid crystal polyester (TLCP), mixtures and poly(methyl methacrylate) (PMMA)-TLCP mixtures were studied. The curing of PMMA-TLCP mixtures was done by heat, gamma radiation and microwave. The amount of TLCP in mixtures was % 0.5, 2 and 5 TLCP by weight. TLCP was synthesized by melt-acidolysis system, and PET-TLCP mixtures were prepared by using lab scale batch mixer. PMMA samples were prepared according to denture manufacturer&rsquo s procedure. The characterization of polymer samples and mixtures were carried by FT-IR, NMR, DSC, DMA, tensile, impact, three point bending tests and light microscopy. The mixing of TLCP with PMMA yielded heterogeneous dispersions. This was observed from light micrographs. The mechanical and rheological properties of all polymers were not positively affected by inclusion of TLCP. It is also worthwhile to note that weakening of PET-TLCP mixtures were due to the thermal degradation as the thermal age of the mixtures is much higher.

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Perez, Luciano Elias da Cruz. "Efeito de tratamentos da superfície de união e materiais reembasadores na resistência ao impacto de resina para base de prótese /." Araraquara : [s.n.], 2005. http://hdl.handle.net/11449/97294.

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Orientador: Ana Lucia Machado Banca: Ana Cláudia Pavarina Banca: Luiz Antonio Pessan Resumo: Este estudo avaliou o efeito de tratamentos da superfície de união e de materiais reembasadores na resistência ao impacto de uma resina para base de prótese. Corpos-de-prova foram confeccionados com a resina Lucitone 550 (60x6x2 mm) e reembasados (2 mm) com o mesmo material (L) ou com as resinas para reembasamento imediato Tokuso Rebase (TR) e Ufi Gel Hard (UH). Para o material L, as superfícies de união permaneceram sem tratamento (L/L/ST) ou foram tratadas com o monômero da resina L (metil metacrilato) for 180 segundos (L/L/M). Quando o reembasamento foi realizado com os reembasadores imediatos, os tratamentos de superfície consistiram de aplicação dos agentes adesivos fornecidos pelos fabricantes (L/TR/A - diclorometano e L/UH/A - diclorometano e 2-hidroxietil metacrilato) ou tratamento com o monômero da resina L seguido pelos adesivos (L/TR/MA e L/UH/MA). Corpos-de-prova do material L intacto (60x6x4 mm) também foram confeccionados para se determinar a resistência ao impacto dessa resina. Um total de 140 corpos-de-prova foi confeccionado, sendo 20 para cada condição experimental. Para metade dos corpos-de-prova, os entalhes foram realizados na largura, na superfície correspondente ao material reembasador, com profundidade de 0,8 mm, permanecendo 3,2 mm de material intacto (E1). Para os corpos-de-prova restantes, o entalhe foi realizado na espessura, envolvendo tanto o material reembasador como a resina de base, com profundidade de 1,2 mm (E2), permanecendo 4,8 mm de material intacto. Todos os entalhes, em forma de V, foram realizados na área central do comprimento dos corpos-de-prova. O teste utilizado foi do tipo Charpy, com pêndulo de 0,5 J e distância de 50 mm entre os suportes. Os resultados (kJ/ m2) de cada entalhe foram analisados, separadamente, utilizando-se ANOVA e teste de ...(Resumo completo, clicar acesso eletrônico abaixo) Abstract: This study evaluated the effect of surface treatments and reline materials on the impact strength of a denture base acrylic resin. Specimens were made using Lucitone 550 resin (60x6x2 mm) and relined (2 mm) with the same material (L) or with the hard chair-side reline resins Tokuso Rebase (TR) and Ufi Gel Hard (UH). For material L, the bond surfaces remained untreated (L/L/ST) or were wetted with resin L monomer (methyl methacrylate) for 180 seconds (L/L/M). When the relining was made with the hard reline materials, the surface treatments consisted of coating with the bonding agents supplied by the manufacturers (L/TR/A - dichloromethane and L/UH/A - dichloromethane and 2-hydroxyethyl methacrylate) or wetting with the resin L monomer followed by bonding agents application (L/TR/MA and L/UH/MA). Material L intact specimens (60x6x4 mm) were also made to determine the impact strength of the bulk resin. A total of 140 specimens were made, 20 for each experimental condition. Half of the specimens were notched across the width to a depth of 0.8 mm, leaving an effective depth under notch of 3.2 mm (E1). For the remaining specimens, the notch was cut across the thickness to a depth of 1.2 mm (E2) leaving an effective depth under notch of 4.8 mm. All the V-notches were machined at the midpoint of the length of the specimens. Impact tests were carried out on a Charpy type pendulum impact tester (0.5 J pendulum; distance between supporting points - 50 mm). Results (kJ/ m2) from each notch depth were analyzed separately using one-way ANOVA and Tukey's HSD tests (a = .05). No significant differences were noted among the mean impact values of L (1.39 kJ/ m2), L/L/ST (1.28 kJ/ m2) and L/L/M (1.20 kJ/ m2) specimens with the E1 notch (P>.05). Similar results were observed (P>.05) for the specimens with the E2 notch (L - 1.00 kJ/ m2; L/L/ST - 0.93 kJ/ m2; ...(Complete abstract, click electronic access below) Mestre

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20

Costa, Cristiane Campos [UNESP]. "Avaliação in vitro da citotoxicidade de resinas acrílicas para reembasamento baseadas em uma nova formulação." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/97299.

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Made available in DSpace on 2014-06-11T19:28:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-03-19Bitstream added on 2014-06-13T20:58:45Z : No. of bitstreams: 1 costa_cc_me_arafo.pdf: 3083928 bytes, checksum: 2605dd91339dbf0d4e3c26e02afc6696 (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) O objetivo deste estudo foi determinar a citotoxicidade in vitro de duas resinas reembasadoras experimentais autopolimerizáveis contendo alta concentração de agentes de ligação cruzada, etilenoglicol dimetacrilato (EGDMA) e 1,4-butanodiol dimetacrilato (BDMA) comparadas com uma resina reembasadora comercial (Tokuyama Rebase Fast II). Foram confeccionados corpos-de-prova em forma de discos das três resinas acrílicas reembasadoras rígidas sob condições assépticas. Os fibroblastos (L929) foram cultivados em placas com 96 compartimentos e incubadas por 24 h em meio de cultura Eagle. Os extratos foram preparados, colocando-se três amostras de cada resina em frascos de vidro estéreis com 9 mL de meio de Eagle e incubadas a 37º C por 24 h. O efeito citotóxico dos extratos foram avaliados utilizando os testes de incorporação do 3H-timidina e MTT, que refletem os níveis de síntese de DNA e metabolismo celular, respectivamente. Os dados foram analisados estatisticamente, utilizando análise de variância (P<0.05). Para o teste de incorporação do 3H-timidina, não foram observadas diferenças significativas (P>0.05) entre os materiais. A média da quantidade do isótopo incorporado no DNA celular para todas as resinas acrílicas foi estatisticamente menor do que para o controle. Todas as resinas acrílicas foram classificadas pelo teste de incorporação do 3Htimidina como moderadamente citotóxicas. Da mesma forma, para o teste do MTT, não foi encontrada diferença significativa para a citotoxicidade entre os materiais (P>0.05). Quando a citotoxidade foi comparado com o grupo controle, todas as resinas foram classificadas entre não citotóxicas e discretamente citotóxicas pelo teste do MTT. Assim, conclui-se que a incorporação dos agentes de ligação cruzada, EGDMA e BDMA não influenciaram significativamente sobre a citotoxicidade observada. Não houve diferença... The aim of this study was to determine the cytotoxicity in vitro of two trials autopolymerizing reline systems made with higher concentration of cross-linking agents, EGDMA and BDMA compared to a commercial reline resin. Sample disks of the three hard reline acrylic resins were fabricated under aseptic conditions. The Fibroblast L929 cells were cultured in 96-well plates and incubated for 24 h in Eagle's medium. Eluates were prepared by placing three samples into a sterile glass vial with 9 mL of Eagle's medium and incubating at 37ºC for 24 h. The cytotoxic effect from the eluates was evaluated using the 3H-thymidine incorporation and MTT assays, which reflect DNA synthesis levels and cell metabolism, respectively. The data were statistically analyzed by using the one-way analysis of variance (P<.05). With the 3H-thymidine incorporation assay, no significant differences (P > .05) were found between the materials. The mean quantity of isotope incorporated into cellular DNA for all acrylic resins was statistically smaller than for the control. All acrylic resins were graded by the 3Hthymidine incorporation assay as moderate cytotoxic. Similarly, with the MTT assay, no significant difference in cytotoxicity was found between the materials (P > .05). When the cytotoxicity was compared with control group, all resins assay were between non cytotoxic and slight cytotoxic by the MTT. The incorporation of cross-linking agents, EGDMA and BDMA had no significant influence on the cytotoxicity observed. There was no cell viability difference between all materials in both assays.

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21

Costa, Cristiane Campos. "Avaliação in vitro da citotoxicidade de resinas acrílicas para reembasamento baseadas em uma nova formulação /." Araraquara : [s.n.], 2009. http://hdl.handle.net/11449/97299.

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Resumo: O objetivo deste estudo foi determinar a citotoxicidade in vitro de duas resinas reembasadoras experimentais autopolimerizáveis contendo alta concentração de agentes de ligação cruzada, etilenoglicol dimetacrilato (EGDMA) e 1,4-butanodiol dimetacrilato (BDMA) comparadas com uma resina reembasadora comercial (Tokuyama Rebase Fast II). Foram confeccionados corpos-de-prova em forma de discos das três resinas acrílicas reembasadoras rígidas sob condições assépticas. Os fibroblastos (L929) foram cultivados em placas com 96 compartimentos e incubadas por 24 h em meio de cultura Eagle. Os extratos foram preparados, colocando-se três amostras de cada resina em frascos de vidro estéreis com 9 mL de meio de Eagle e incubadas a 37º C por 24 h. O efeito citotóxico dos extratos foram avaliados utilizando os testes de incorporação do 3H-timidina e MTT, que refletem os níveis de síntese de DNA e metabolismo celular, respectivamente. Os dados foram analisados estatisticamente, utilizando análise de variância (P<0.05). Para o teste de incorporação do 3H-timidina, não foram observadas diferenças significativas (P>0.05) entre os materiais. A média da quantidade do isótopo incorporado no DNA celular para todas as resinas acrílicas foi estatisticamente menor do que para o controle. Todas as resinas acrílicas foram classificadas pelo teste de incorporação do 3Htimidina como moderadamente citotóxicas. Da mesma forma, para o teste do MTT, não foi encontrada diferença significativa para a citotoxicidade entre os materiais (P>0.05). Quando a citotoxidade foi comparado com o grupo controle, todas as resinas foram classificadas entre não citotóxicas e discretamente citotóxicas pelo teste do MTT. Assim, conclui-se que a incorporação dos agentes de ligação cruzada, EGDMA e BDMA não influenciaram significativamente sobre a citotoxicidade observada. Não houve diferença... (Resumo completo, clicar acesso eletrônico abaixo) Abstract: The aim of this study was to determine the cytotoxicity in vitro of two trials autopolymerizing reline systems made with higher concentration of cross-linking agents, EGDMA and BDMA compared to a commercial reline resin. Sample disks of the three hard reline acrylic resins were fabricated under aseptic conditions. The Fibroblast L929 cells were cultured in 96-well plates and incubated for 24 h in Eagle's medium. Eluates were prepared by placing three samples into a sterile glass vial with 9 mL of Eagle's medium and incubating at 37ºC for 24 h. The cytotoxic effect from the eluates was evaluated using the 3H-thymidine incorporation and MTT assays, which reflect DNA synthesis levels and cell metabolism, respectively. The data were statistically analyzed by using the one-way analysis of variance (P<.05). With the 3H-thymidine incorporation assay, no significant differences (P > .05) were found between the materials. The mean quantity of isotope incorporated into cellular DNA for all acrylic resins was statistically smaller than for the control. All acrylic resins were graded by the 3Hthymidine incorporation assay as moderate cytotoxic. Similarly, with the MTT assay, no significant difference in cytotoxicity was found between the materials (P > .05). When the cytotoxicity was compared with control group, all resins assay were between non cytotoxic and slight cytotoxic by the MTT. The incorporation of cross-linking agents, EGDMA and BDMA had no significant influence on the cytotoxicity observed. There was no cell viability difference between all materials in both assays. Orientador: Eunice Teresinha Giampaolo Coorientador: Iracilda Zeppone Carlos Banca: Renata Cristina Silveira Rodrigues Ferracioli Banca: Iracilda Zeppone Carlos Mestre

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22

Aliaga, Adelaida Sánchez. "EFEITO DA INCORPORAÇÃO DE FÁRMACOS ANTIFÚNGICOS SOBRE A MORFOLOGIA DE SUPERFÍCIE E A LIBERAÇÃO IN VITRO DE MATERIAIS MACIOS TEMPORÁRIOS PARA BASE DE PRÓTESE." UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2014. http://tede2.uepg.br/jspui/handle/prefix/1839.

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Made available in DSpace on 2017-07-24T19:22:34Z (GMT). No. of bitstreams: 1 Adelaida S Aliaga.pdf: 5670394 bytes, checksum: 9cdda52bc2a6b833409747ce8d7cf507 (MD5) Previous issue date: 2014-02-21 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Purpose: The purpose of this study was to evaluate the surface morphology and roughness and the in vitro leachability of temporary soft liners modified by the incorporation of antifungals, generally used for the denture stomatitis treatment, in their minimum inhibitory concentrations (MIC) for the biofilm of Candida albicans. Material and methods: The surface analyses of the tissue conditioner Softone (S) and the resilient liner Trusoft (T) modified or not by the addition of nystatin (Ny), miconazole (Mc), ketoconazole (Ke), chlorhexidine diacetate (Chx), and itraconazole (It) were made by using scanning electron microscopy and confocal laser microscopy. In vitro leachability of Ny and Chx was measured using Ultraviolet visible spectroscopy. Additional analyses of the modified materials containing Ny and Chx were made using differential scanning calorimetry (DSC). The antifungals were incorporated at their previously determined MIC for the biofilm of C. albicans (Ny = 0.032 g; Mc = 0.256 g; Ke = 0.128 g; Chx = 0.064 g; and It = 0.256 g/g of material). The specimens were stored in distilled water at 37ºC for up to 14 days previously to the analyses. Results: Softone had more irregular surface morphology than Trusoft did. Morphological changes were noted in both materials with increasing immersion time, particularly in those containing drugs. Ny and Ke showed the smallest particle sizes, while Chx and It showed the largest ones. Groups containing Chx and It presented extremely porous and irregular surface. Modified specimens had superior roughness (Ra) values in comparison with the control specimens. There was a trend towards an increase in Ra parameter after 7 days, followed by a decrease to values lower than the initial ones after 14 days, in the control and specimens with Ny, Mc, and Ke. Both materials had biexponential kinetics of release: a rapid initial release followed by a slower leaching. Softone leached more concentration of the antifungals than Trusoft and chlorhexidine was released at higher concentration than nystatin. DSC analysis revealed low Tg for Softone and that the fusion temperature of the drugs changed little after they had been added to the materials. Conclusion: The addition of Chx or It changed more significantly the surface of the materials. Softone was able to release more drug concentration and it was noted a weak chemical bond between the drugs and the evaluated materials. Objetivo: A proposta deste estudo foi avaliar a morfologia e a rugosidade de superfície e a liberação in vitro de materiais macios temporários com incorporação de fármacos antifúngicos, comumente utilizados para o tratamento da estomatite protética, em suas concentrações mínimas inibitórias (CMI) ao biofilme de Candida albicans. Material e métodos: As análises de superfície do condicionador de tecido Softone (S) e do reembasador resiliente Trusoft (T) tanto controles como modificados pela incorporação de nistatina (Ni), miconazol (Mc), cetoconazol (Ce), diacetato de clorexidina (Clx) e itraconazol (It) foram feitas por meio de microscopia eletrônica de varredura e microscopia confocal laser. A liberação in vitro dos fármacos Ni e Clx foi quantificada utilizando espectrofotometria na região do Ultravioleta visível. Análises adicionais dos materiais contendo Ni e Clx foram feitas utilizando calorimetria exploratória diferencial (DSC). Os antifúngicos foram incorporados em suas CMI ao biofilme de C. albicans determinadas em estudo prévio (Ni = 0,032 g; Mc = 0,256 g; Ce = 0,128 g; Clx = 0,064 g e It = 0,256 g/g do material). Os corpos de prova foram armazenados em água destilada a 37ºC por até 14 dias previamente às análises. Resultados: O Softone apresentou morfologia mais irregular que o Trusoft. Foi notada alteração de superfície em ambos os materiais, principalmente naqueles contendo fármacos, com o aumento do tempo de imersão. Os maiores e os menores tamanhos de partículas foram dos fármacos Clx e It e Ni e Ce, respectivamente. Os grupos contendo Clx e It demonstraram superfícies extremamente porosas e irregulares. Os espécimes modificados apresentaram valores superiores de rugosidade média (Ra) em relação aos controles. Houve uma tendência de aumento de Ra após 7 dias, seguida por uma diminuição a valores inferiores aos iniciais após 14 dias para o grupo controle e aqueles contendo Ni, Mc e Ce. Ambos os materiais apresentaram cinética de liberação biexponencial: rápida liberação inicial seguida por uma liberação mais lenta. O Softone liberou maior concentração dos fármacos que o Trusoft e a clorexidina foi liberada em maior quantidade que a nistatina. As análises em DSC revelaram Tg mais baixa para o Softone e que a temperatura de fusão dos fármacos pouco alterou após terem sido incorporados aos materiais. Conclusão: A incorporação de Clx ou It alterou mais significativamente a superfície dos materiais. O Softone foi capaz de liberar maior concentração dos fármacos Clx e Ni e foi detectada uma fraca ligação química entre estes fármacos e os materiais avaliados.

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Zanetti, Glauco Rangel. "Influencia do material de inclusão e apoio da grade metalica na estabilidade de proteses parciais removiveis de extremidade livre durante o processamento das bases polimerizadas por energia de microondas." [s.n.], 2000. http://repositorio.unicamp.br/jspui/handle/REPOSIP/290537.

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Orientador: Celia Marisa Rizzatti Barbosa Tese (doutorado) - Universidade Estadual de Campinas. Faculdade de Odontologia de Piracicaba Made available in DSpace on 2018-07-28T03:15:46Z (GMT). No. of bitstreams: 1 Zanetti_GlaucoRangel_D.pdf: 4522575 bytes, checksum: 4717fe0797e79a21a39c9cbeebb8ac1d (MD5) Previous issue date: 2000 Resumo: Este estudo avaliou a influência do material de inclusão (gesso tipo 11 Herodent@ "G", silicone por condensação laboratorial Zetalabor@ "Z"), e da configuração da porção distal da grade metálica (com apoio "C" e sem apoio "s" sobre o modelo), nas alterações horizontais (esquerda "HE" e direita "HD") e verticais (esquerda "VE" e direita "VD") , entre as porções distais de estruturas metálicas de prõteses parciais removíveis (PPR's) e seus respectivos modelos durante o processamento das bases em resina acrílica. Foram utilizados modelos simulando uma arcada inferior parcialmente desdentada classe I de Kennedy. Quarenta amostras padronizadas foram divididas em quatro grupos. As bases foram processadas com uma resina polimerizada por energia de microondas (Onda-Cryl@). Os dados foram submetidos à análise de variância e as médias, ao teste de Tukey (p<O,O5). Os resultados das médias das alterações em milímetros, nos grupos GC (HE=0,2043; HD=0,1610; VE=0,0599; VD=0,0599), GS (HE=O,1888; HD=0,1156; VE=0,2063; VD=O,2420), ZC (HE=0,1796; HD=0,2025; VE=O,0717; VD=0,1396), ZS (HE=0,2043; HD=0,O746; VE=O,2143; VD=0,2880) indicaram que: na VE e VD, G não diferiu de Z, mas C apresentou alterações significativamente menores que S; na HE os grupos não diferiram estatisticamente entre si; na HD não houve diferença significativa entre (ZC e GC), (GC e GS), (GS e ZS) e as alterações foram progressivamente maiores em ZS, GS, GC e ZC Abstract: This study evaluated the effect of two types of investment material ("G", type 11 dental stone, Herodent@; "Z", condensation silicone, Zetalabor@) and two types of design of the distal portion of the metallic framework ("S", with support in the model; "N", without support in the model) in the horizontal ("H L", left; "HR", right) and vertical ('VL", left; 'VR", right) distance changes between the distal portion of the metallic framework and their respective models during processing of the acrylic bases. A lower Kennedy Class I model was used. Forty standardized RPD's were prepared and equally divided into 4 groups. The RPD's bases were processed using a microwave-cured acrylic resin (OndaCryl@). Data was submitted to a "Tukey's Studentized" test (p<O.O5). The results of the means alterations in millimeters, in the groups GS (HL=O.2043; HR=O.1610; VL=O.O599; VR=O.O599), GN (HL=O.1888; HR=O.1156; VL=O.2063; VR=O.2420), ZS (HL=O.1796; HR=O.2025; VL=O.O717; VR=O.1396), ZN (HL=O.2043; HR=O.O746; VL=O.2143; VR=O.2880) showed that for VL and VR measurements, G and Z were not different, and S showed statistical lower changes than N. There was not difference of HL among groups. Considering HR, there was no statistical difference between groups for each following pair: ZS-GS, GS-GN and GN-ZN. Changes were crescent in the order ZN, GN, GS and ZS Doutorado Protese Dental Doutor em Clínica Odontológica

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Cornejo, Seminario Gissela. "Mejora en el proceso de relación con proveedores dentro de la cadena de abastecimiento de una empresa productora de tolvas en base al método de solución de problemas." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2013. http://hdl.handle.net/10757/273427.

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Liens, Aléthéa. "On the potential of Ti-based Bulk Metallic Glasses and Ce-TZP zirconia composites for the development of innovative dental implants." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI117.

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Récemment, la réduction de taille des dispositifs implantés est devenue une tendance majeure de l’implantologie dentaire moderne. Cependant, elle nécessite le développement de matériaux présentant de fortes résistances mécaniques. Le titane et ses alliages, matériaux dentaires de référence, semblent avoir atteint un plateau en termes de propriétés mécaniques, ce qui peut limiter leur utilisation pour une telle stratégie. Les alliages métalliques amorphes à base de titane constituent une classe unique de matériaux présentant de fortes limites d’élasticité qui en font des candidats potentiels pour la réalisation de pièces implantables de petit diamètre. Nous assistons aussi à un intérêt croissant pour les implants en céramiques. La couleur blanche de la zircone yttriée (Y-TZP), combinée à sa capacité unique de résistance par transformation de phase en ont fait un matériau de choix pour la réalisation d’implant dentaires plus esthétiques. Cependant, la zircone yttriée peut être sensible à un mécanisme de dégradation à basse température en milieu aqueux, qui a pu susciter certaines inquiétudes. De plus, même si elle est plus résistante que la plupart des autres céramiques, elle reste un matériau élastique-fragile, sans plasticité, et donc sensible à la présence de défauts. Différentes céramiques dopées à l’oxyde de cérium (Ce-TZP) ont été développées au cours des dernières années et certains de ces matériaux ont montré une ténacité considérable et une plasticité de transformation significative comparées aux céramiques conventionnelles. Cette combinaison de propriétés en fait des candidats potentiels pour la réalisation d’implants dentaires esthétiques, comme alternatives crédibles à la 3Y-TZP. Durant ce travail de thèse, le potentiel de ces deux matériaux, pour deux applications différentes a été étudié. La première application concerne la réalisation d’implants dentaires mini-invasifs en remplacement du titane. La seconde application est centrée sur la réalisation de nouveaux implants esthétiques en céramique, plus tenaces et plus fiables, en remplacement de la 3Y-TZP. La première partie de ce travail sera axée sur le verre métallique Ti40Zr10Cu36Pd14. Le potentiel de ce verre métallique pour la fabrication de futurs implants mini-invasifs sera démontré et sa plus-value en termes de résistance à la fatigue comparé aux titanes biomédicaux conventionnels sera mise en évidence. Le rôle des éléments d’alliage tels que l’étain et le silicium sur les propriétés globales de l’alliage, telles que la cytocompatibilité et la résistance à la corrosion, sera également analysé. La deuxième partie de ce travail portera sur un nouveau composite à base de Ce-TZP. La résistance mécanique de ce matériau sera évaluée et comparée à la 3Y-TZP. De plus, sa plasticité de transformation unique et ses conséquences sur le comportement mécanique de ce matériau seront approfondies et décrites à l’aide d’expériences originales Recently, dental implant downsizing has become one major trend in modern implantology but it requires the development of materials with improved mechanical resistance. Never- theless, titanium and its alloys, the gold standard dental materials, seem to have reached a plateau in terms of mechanical properties, which may limit their use for such strategy. Amorphous titanium-based metallic alloys are a unique class of materials showing high mechanical and fatigue properties, good corrosion resistance and a relatively low Young’s modulus, which thus make them potential candidates for the realization of such-small diameter implantable pieces in substitution to polycrystalline titanium. There is also a growing trend to use ceramic implants in dentistry. In particular, the white color of Yttria-Tetragonal Zirconia Polycrystal (Y-TZP) materials combined with their unique transformation toughening ability have made them materials of choice for the realization of metal-free, aesthetic dental implants. However, ageing of Y-TZP ceramics in aqueous environments may be a concern and even if strongest than many other ceramics, Y-TZPs still remain elastic-fragile with a sensitivity to the presence of defects. Various Ceria-doped based zirconia ceramics have been developed over the past years, in particular during two recent European projects led by MATEIS and Anthogyr. These materials may be highly resistant to flaws with a considerable toughness and an unusual transformation- induced ductility. This unique combination of properties makes them potential candidates for the realization of ceramic dental implants, as an alternative to 3Y-TZP. Within this PhD work, the potential of the two materials for (i) the realization of less invasive implants to replace titanium alloys on one hand, and (ii) aesthetic and more reliable ceramic implants as alternative to 3Y-TZP on the other hand, will be studied. The first part of this work will be focused on Ti40Zr10Cu36Pd14 metallic glass. The potential of this amorphous alloy for future implantable devices fabrication is assessed in terms of ion release in relevant media, corrosion resistance, biocompatibility and fatigue resistance, with a comparison to the benchmark conventional biomedical grade Ti alloys. The role of Sn and Si alloying elements on the overall properties of the alloy will be also analyzed. The second part of this work will deal with a new Ce-TZP based composite. Mechan- ical characterization and fatigue resistance will be evaluated and compared to 3Y-TZP material. Furthermore, the transformation-induced plasticity of this composite will be better understood, thanks to original experiments, in order to validate its reliability and its absence of potential damage under stress. All the results may open new perspectives in the future of dental applications

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YANG, SHIH-HONG, and 楊士弘. "The Effect of Digital Light Processing on Properties of Denture Base Material." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/a2rfgt.

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碩士 中臺科技大學 牙體技術暨材料系碩士班 107 Polymethyl methacrylate（PMMA）applied to denture base material in clinical still has problems with polymerization shrinkage and monomer volatilized. Recently, digital light processing（DLP）technology is rapidly developing in dental technology, this technology is use three-dimensional print（3D Print）to make denture base materials. A novel denture manufacture method, can improve the work efficiency of denture manufacture. However, the influence mechanism of DLP technology for mechanical properties on the denture base material is still very limited. The study is to comparison of denture base properties between digital light processing technique and conventional thermal polymerization method. Three different build orientation（X- coordinate, Y- coordinate, Z- coordinate）were printed. The corresponding resin specimens were designated as DX, DY and DZ, respectively. The traditional thermal polymerization resin（control group）was designated as TH. The results show that the DZ build orientation show the best surface hydrophilicity, surface hardness and bending strength, which is the close to the mechanical properties of the traditional thermal denture base material.

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Chu, Chang-Chieh, and 初昌傑. "Investigation of peel force of soft-lining material to various denture base treatments." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/93586993166119707681.

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碩士 中山醫學院 口腔醫學研究所 89 英文摘要 Temporary soft-lining materials are frequently used in patients whose thickness of the alveolar bone in the edentulous areas appears thin and the elasticity becomes anomalous. This kind of alveolar ridge cannot bear the general resin denture base. Therefore, temporary soft-lining materials are used to reduce the bearing load of alveolar ridge. The use of temporary soft-lining materials increasingly has come into favor for various applications in prosthetic dentistry, including use with dental implants for promote surgical wound healing and retention. Nevertheless, it is time-consuming when substituting liners; worse, the replacement procedure may even damage the denture base. The purpose of this study was to assess the different surface bond strengths of denture base materials ( acrylic resin denture base- Lucitone 199a and visible light-cured denture base- Triada ) under various surface treatments and thermocycles conditions. The results may offer some insights into the feasibility of replacement of temporary soft-liners cliniclly. Two denture base materials, Lucitone 199 ( Dentsply/York Division, York, Pa. ) and Triad ( Dentsply International Corporation, York, Pa. ), were used in this study. The size of each material is 75 mm×25 mm×2.5 mm . Total samples are 400 and divided into four groups ( 100/each group consisting of 50 Lucitone 199 and 50 Triad ) as follows: Group (A) No treatment; Group (B) Sandblast; Group (C)TC-SEPARATOR and Group(D) Sandblast treatment followed by TC-SEPARATOR. The thickness of specimens consisted of 2.5 mm of Lucitone 199 or Triad and 2.5 mm of Coe-Soft (GC Co ), being bonded over 25 mm of the length of the specimen and separated over the remaining 50 mm. Immediately the specimens were immersed in 37oC normal saline for 24 hours and then ten specimens in each group were dipped for 20 seconds in 4 o C and 55 o C normal saline with a travel time of 5 seconds for 0, 150, 300, 600, 1200 thermocycles. All of the specimens were subjected to a peeling force by separation of the serrated grips at a constant rate of 100 mm/min in an universal testing machine ( AUTOGRAPH AGE-1000E Shtmadzu,Japan ). The peel force and nature of failure for each specimen was recorded. A three-way ANOVA followed by a Tukey's test was used to analyze the data. The peel force of sandblast treated specimens had the highest value ( p<0.01 ). Denture base treated by sandblast + TC-SEPARATOR showed a higher peel force than that of treated by TC-SEPARATOR specimens but lower than that of no treatment and treated alone by sandblast specimens ( p<0.01 ). Statistically, the peel force of cycle 600, 0,300,150 specimens showed is significantly lower than that of cycle 1200 specimens ( p<0.01 ). Taken together, the treatments of sandblast followed by TC-SEPARATOR do not damage the bonding force between either Lucitone 199 with Coe-Soft or Triad with Coe-Soft. The bond strength of the sandblast + TC-SEPARATOR is not too week to cause peeling off of denture base. The peeling force is only marginally below clinical scope. Overall, it is a feasible surface treatment on denture base materials based on the advantages of (1) easy replacement yet not causing peeling off; (2) time-saving and (3) maintaining denture base strength.

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Okeke, Kenneth Nkemdilim. "The efficacy of Hibiscus sabdariffa as a fibre-reinforcement material for denture base acrylic resins." Thesis, 2017. http://hdl.handle.net/10321/2923.

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Submitted in fulfillment of the requirements for the award of the degree of Master of Health Sciences: Dental Technology, Durban University of Technology, Durban, South Africa, 2017. The poor mechanical properties of denture base acrylic resins can cause dentures to fracture either through impact or stress fatigue. Various metal reinforcing materials such as powders, nets, plates and wires together with synthetic fibres are therefore used to improve the strength properties of denture base acrylic resins. Despite their benefits, they are difficult to apply during fabrication, are costly, non-recyclable, and not environmentally friendly. The suitability of Hibiscus sabdariffa (H. sabdariffa) as a fibre reinforcement material for denture base acrylic resins was therefore investigated. A quantitative research paradigm and a two-phased experimental research design was used. The preliminary study used Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA) and field emission scanning electron microscope (FE-SEM) to assess the characteristics of, and the effect of, mercerisation on H. sabdariffa fibres. In determining the suitability of H. sabdariffa fibres, fibre diameter, fibre density, moisture content and absorption were examined. The main study investigated the mechanical and physical properties of two sample groups namely: the unreinforced (control) group and the H. sabdariffa fibre-reinforced (test) group denture base acrylic resins. The flexural strength, impact strength, specific wear rate, hardness and water absorption behaviour were determined in line with ASTM D 790 and D 256, G 99, D 2583 and D 570 methods of testing, respectively. Parametric and non-parametric tests were used to analyse the mean differences (p = 0.05) between the unreinforced and the H. sabdariffa fibre-reinforced denture base acrylic resins. The preliminary study revealed that H. sabdariffa fibres favourably compared to other lignocellulosic fibres in terms of fibre diameter, fibre density, water content and absorption behaviour. In the main study, a t-test revealed that there were significant differences in flexural strength at 0oC (p < 0.0001) and at 65oC (p < 0.0025) between the two sample groups. Similarly, there were significant differences in the impact strength between the two sample groups at 0oC (p < 0.031) and at 65oC (p < 0.0001). In contrast to the 200g load, there were significant differences (p < 0.044) in the specific wear rate of the unreinforced and the H. sabdariffa fibre-reinforced denture base acrylic resins at the 500g load. The hardness values revealed no significant differences (p > 0.707) between the two sample groups. There were however, significant differences (p < 0.041) in the water absorption rate between the two sample groups. Overall, the prominent features of this study showed that H. sabdariffa fibre is a suitable reinforcement fibre material for denture base acrylic resins and is in compliance with ISO 1567: 1999. Although this study found that H. sabdariffa fibres can be used as reinforcement material for denture base acrylic resins, the results cannot be generalised to clinical conditions, therefore in vitro and in vivo investigations are recommended. M

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Tsai, Tung Ying, and 蔡東螢. "Effects of Repair Material, Joint Surface Contour and Weathering Agent on Transverse Strength of Repaired Denture Base." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/33915156730174326134.

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碩士 台北醫學院 牙醫學類 84 Joint surface contour, repair material and weathering agent solution will all effect the transverse strength of the repaired denture base. In this study, Luciton 199 ( Dentsply, USA ) was used as the denture base substrate with diff-erent repair-joint designs (butt, round, and 45 degree bevel ). Specimens of denture base acrylic resins were repaired with autopolymerized ( Repair Materi-al, Dentsply USA ) and visible light-cured ( Triad, Dentsply, USA ) repair mat-erials. Repaired specimens were soaked in 99.5 % ethanol ( as a weathering agentsolution ) at 37'C for different time periods, their transverse strengths were then measured by a three - point bending test with a universal testing machine. ( AGS-1000D, SHIMADZU, JAPAN, cross- head speed : 5mm / min ) Instead of beingsoaked in 99.5 % ethanol, the control group was in distilled water. Scanningelectron microscope ( SEM ) and optical microscope were used to examine the fra-cture patterns and surfaces

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Alsulaimani, Othman Saleh. "Mechanical properties and shear bond strength of denture teeth to different denture base materials." Thesis, 2021. https://hdl.handle.net/2144/42684.

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OBJECTIVES: The aim of this in vitro study is to investigate the mechanical properties and bond strength of denture teeth to recently introduced denture base materials. MATERIALS AND METHODS: From high-impact pourable acrylic HIPA (Dentsply Sirona), DSDM Lucitone 199 puck (Dentsply Sirona), and digitally printed (Dentsply Sirona) denture base materials, bar specimens were fabricated for flexural testing (10 × 3.3 × 64 mm3) and fracture toughness testing (8 × 4 × 39 mm3). Tensile strength specimens were fabricated to form dumbbell-shaped specimens (3 × 6 mm cross-section) with a central bar. Micro-tensile specimens were fabricated into 10 × (1.5 ± 0.2) × (1.5 ± 0.2) mm3 bars. The treated specimens were subjected to thermal cycling. Square plates (3 × 18 mm2) were prepared for bonding to IPN denture teeth rods (3.85 mm) for evaluation of shear bond strength after surface treatment with airborne particle abrasion of 50 m aluminum oxide powder. The means were compared using an ANOVA Tukey HSD test, paired Student’s t-test, and contingency test (α = 0.05). RESULTS: DSDM had statistically higher flexural strength (p < 0.0001) than the other tested materials, as determined by one-way ANOVA. However, all denture base materials’ flexural moduli were not statistically different (p = 0.22). The effect of thermal aging on flexural strength (p = 0.18) and moduli of tested materials (p = 0.83) was not statistically significant. DSDM demonstrated statistically higher fracture toughness values (p = 0.0013) than the other materials. HIPA, however, had statistically higher work of fracture values than the other materials tested (p < 0.0001). The effect of thermal aging on Kmax and fracture work of all tested materials (pooled) was statistically different (p = 0.0002 and p = 0.0132, respectively). DSDP had the statistically highest tensile strength, followed by DSDM, and HIPA had the lowest (p < 0.0001). The effect of thermal aging on tensile strength (pooled) was statistically different (p <0.0001). The HIPA material’s mean micro-tensile strength was significantly lower than the DSDM and DSDP materials (p < 0.0001). Furthermore, the effect of thermal aging on the micro-tensile strength of all tested materials (pooled) was statistically different (p = 0.0005). Each paired Student’s t-test showed that surface abrasion increased the shear bond strength of DSDM, DSDP, and HIPA materials significantly (p < 0.0001, p = 0.0037, and p = 0.0035, respectively). Contingency analysis of the effect of the surface abrasion on each material’s failure mode revealed a 100% adhesive failure mode in DSDM. In DSDP, 5% of the failure mode was mixed. In contrast, the analysis showed 40% cohesive, 50% adhesive, and 10% mixed failure modes in HIPA material, although this finding was not statistically significant (p = 0.32). CONCLUSIONS: DSDM had higher flexural strength than the other tested materials and maximum stress intensity factors. However, HIPA performed better in terms of flexural modulus work of fracture. DSDP material had higher tensile strength values than the other materials. Thermocycling increased flexural strength, modulus values, and fracture toughness values, except for DSDP material which its work of fracture reduced after thermocycling. The tensile strength values of all tested materials was reduced after thermocycling. Air abrasion treatment enhanced the bonding strength between denture teeth and denture base material. Fractographic analysis of fragmented HIPA and DSDM specimens revealed varying degrees of plastic deformation, while DSDP material exhibiting less plastic deformation. 2021-12-13T00:00:00Z

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Basunbul, Anhar Islem. "Analysis of the mechanical and physical properties of printed and milled denture base materials." Thesis, 2021. https://hdl.handle.net/2144/42832.

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OBJECTIVES: Evaluate the mechanical properties of commercial digital denture base materials. Materials: The materials used were Lucitone 199 denture base disc (Dentsply Sirona), AvaDent denture base puck (AvaDent), KeyMill denture base disc (Keystone), Lucitone digital print denture base resin (Dentsply Sirona), Formlabs denture base resin (Formlabs), and Dentca denture base resin II (Dentca). METHODS: For each material, 60 bar-shaped specimens were prepared for flexural testing, which were divided into 5 groups including control, fatigue, thermocycling, and repairing using 2 types of materials. 24 square-shaped specimens were included in the bond testing, bonded to tooth and composite resin. Additionally, 48 square-shaped specimens were fabricated for the color stability testing, against UV light and staining and washing solutions. The flexural strength and modulus were calculated through 3-point bend test. Bond strength was determined using shear bond test. Color coordinates were recorded in the CIE L*a*b* system using an X-Rite Ci7600 spectrophotometer. Color differences relative to the baseline (∆E^*) were obtained. Data were analyzed using one-way ANOVA followed by Tukey’s HSD test (α=0.05). RESULTS: Milled materials showed higher flexural strength than printed materials. Fatigue and thermocycling led to a decrease in the flexural strength of both group materials. Repaired groups showed flexural strength of about 30.67% and 32.80% of its original strength, in milled and printed materials respectively. However, the flexural strength of the printed materials was affected by the type of the repair material, composite resin gave higher values compared with acrylic. Printed materials exhibited superior bond strength to tooth and composite resin than milled materials. The color change under UV light was clinically acceptable. The color change after immersion in staining and washing solutions in milled groups was less noticeable than in the printed group. Thermocycling treatment made the color change more noticeable in both milled and printed groups. CONCLUSION: Milled denture materials exhibited higher flexural properties than printed denture materials. Printed materials exhibited higher shear bond to tooth and composite resin. The color stability of milled materials with staining and washing solutions treatment was better than the printed groups, whereas the color stability of milled and printed materials exposed to UV light was clinically acceptable. 2023-08-03T00:00:00Z

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Chien, Liao Wein, and 廖文堅. "Adhesion characteristics of silicone soft lining materials bonded to denture base resin." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/89110628820196777656.

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Nejatian, T., Farshid Sefat, and T. Johnson. "Impact of packing and processing technique on mechanical properties of acrylic denture base materials." 2015. http://hdl.handle.net/10454/9480.

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Yes The fracture resistance of polymethylmethacrylate (PMMA) as the most popular denture base material is not satisfactory. Different factors can be involved in denture fracture. Among them, flexural fatigue and impact are the most common failure mechanisms of an acrylic denture base. It has been shown that there is a correlation between the static strength and fatigue life of composite resins. Therefore, the transverse strength of the denture base materials can be an important indicator of their service life. In order to improve the fracture resistance of PMMA, extensive studies have been carried out; however, only a few promising results were achieved, which are limited to some mechanical properties of PMMA at the cost of other properties. This study aimed at optimizing the packing and processing condition of heat-cured PMMA as a denture base resin in order to improve its biaxial flexural strength (BFS). The results showed that the plain type of resin with a powder/monomer ratio of 2.5:1 or less, packed conventionally and cured in a water bath for 2 h at 95 °C provides the highest BFS. Also, it was found that the performance of the dry heat processor is inconsistent with the number of flasks being loaded.

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Fan, Chun-chieh, and 范俊哲. "Incorporation of anti-fouling properties on denture base materials by chemical grafting methods." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/7ru976.

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碩士 國立臺灣科技大學 化學工程系 100 The common problems encountered for dentures include: (i) the loss of adhesion between soft linings and denture base, and (ii) the growth of microorganism and formation of biofilm on the denture which usually resulted in bad smelling and hygiene concerns. This study aims to incorporate antifouling molecules onto the denture base materials and to evaluate the variation of the adhesion between soft linings (Molloplast B) and denture bases (Luctione 199). Two chemical grafting methods were proposed in this study to incorporate mPEG (poly(ethylene glycol) methyl ether), a derivative of PEG (polyethylene glycol), on the denture base which is mainly composed of PMMA (polymethyl methacrylate). The first method involved to modify one end of mPEG from –OH group to –COOH by reacting with succinic anhydride (forming mPEG-COOH), and further reacted with thionyl chloride to form mPEG-COCl. PMMA denture base was reacted with LiAlH4 to form PMMA-OH that the highly reactive mPEG-COCl would react with PMMA-OH to specifically graft mPEG on PMMA and form mPEG-PMMA. In this part of studies, different solvents systems and two molecular weight of mPEG were used to study their effects on fouling resistance. The formed products were named as mPEG-2k-COCl-PMMA and mPEG-5k-COCl-PMMA. The second chemical graft method is to modify mPEG and PMMA both in two steps. PMMA was firstly reacted with LiAlH4 and propargyl bromide to form PMMA-OH and PMMA- alkyne, respectively. The –OH end group of mPEG was modified by thionyl chloride and sodium azide (NaN3) to form mPEG-Cl and mPEG-N3, sequentially. The alkyne-azide reaction between PMMA- alkyne and mPEG-N3 was specific and commonly called “click chemistry” reaction. Two different M.W. of mPEG were studied and the formed products were named as mPEG-2k-click-PMMA and mPEG-5k-click-PMMA. The mPEG incorporation is believed to provide the brush-like structure on the surface of PMMA to resist the adhesion of biomolecules. Moreover, the identification of chemical structure and synthesis were performed using FTIR, 1H NMR and ESCA. The surface morphology was visualized by SEM. The results showed that the two proposed methods increased the antifouling efficiency on the dental based materials. Firstly, the “esterification” reaction resulted in 39.8 % and 36.5 % for mPEG-2k-COCl-PMMA and mPEG-5k-COCl-PMMA. Furthermore, the “click chemistry” reaction promoted the antifouling efficiency up to 63.4 % and 81.3 % on mPEG-2k-click-PMMA and mPEG-5k-click-PMMA. The results of mechanical tests showed that the similar mechanical strength was obtained between soft lining and denture base on mPEG-2k-COCl-PMMA.The other three modifications resulted in slightly decreases of mechanical strength between the modified denture base and soft linings.

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HSUEH, YA-MING, and 薛亞銘. "Antibacterial Ability Evaluation of adding Precipitates of Hot Springs in to the Acrylic Denture Base Materia." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/2366z8.

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碩士 嘉南藥理大學 觀光事業管理系 107 In this study, the precipitates of hot springs was added to the acrylic denture base materia, and the bacteriostasis test was used to evaluate the feasibility of adding the Precipitates of Hot Springs to the whole mouth denture material. This research selected two kinds of hot spring water to be the models, which are the green sulfonic springs and white sulfonic springs. The purpose of the research is to improve the health and quality of life of human beings through the diversified use of hot springs resources. The first experiment is start from by making the test sample, that are made from the acrylic denture base materia, which are added the different percentage of the precipitates of hot springs. After the coliform group was cultured, it was measured by an ATP luminometer. The second experiment is comparing bacteriostasis ability of different liquid. We choose 4 types of liquid as the test samples, green sulfonic springs, white sulfonic springs, Mouthwash and Denture cleaning ingot. To obtain the result, this experiment is dipped the acrylic denture base materia in the liquid for 24 hours. After cultivating coliform count, it is measured with an ATP luminometer,and the ATP luminometer was used to continuously test the three-day. According to the experiment, the conclusions are as follows: 1. The surface bacteriostasis ability of the test sample with the precipitates of hot springs (green sulfonic springs) is better than that of the test sample the the precipitates of hot springs (white sulfonic springs). 2. The green sulfonic springs and the white sulfonic springs have good bacteriostasis ability; the commercial potential of these two hot spring denture cleaning products can be developed.

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Henning, Martha Carolina. "The effect of glass fiber polysulphone composite reinforcement on flexural strength of two denture-base polymers." Diss., 2003. http://hdl.handle.net/2263/28303.

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Statement of the Problem: Despite its popularity as a denture-base material, poly-methyl methacrylate exhibits inherently low resistance to impact and fatigue failure. This is reflected in the analyses of the prevalence of denture fracture which suggests that prosthesis failure remains an unsolved problem. Consequently, various approaches to improve the physical and mechanical properties of denture-base polymers have been proposed. These include incorporation of solid metal forms and various types of fibers to provide reinforcement to fracture prone areas. In recent years there has been considerable interest in glass fiber reinforcement of polymeric denture resins. Partial fiber reinforcement using glass fiber has been shown to improve the mechanical properties of removable prostheses. However, adequate impregnation of fibers often requires the use of excessive methyl methacrylate monomer which has a deleterious effect on the mechanical properties of the fiber composite material. Purpose: The aim of the present study was to determine the effect of glass fiber polysulphone composite reinforcement on the flexural characteristics of two commonly used denture-base polymers. Materials and methods: Prefabricated E-glass fiber polysulphone composite rods, ± 3mm in diameter, with a continuous, unidirectional, non-silanized fiber concentration of ± 55 vol %, were employed as strengtheners. The reinforcement was incorporated axial to the neutral axis in standardized cylindrical heat polymerizing conventional and high impact resin test specimens 6mm in diameter and 28mm in length. The two reinforced pattern groups (n = 10) were compared with unreinforced resin control groups. A three point loading test was performed in air after storage of the specimens in water at 37°C for a period of 8 weeks. The following values were measured : flexural modulus and flexural strength. The obtained data were subjected to relevant statistical analysis. Results: The flexural modulus of the glass fiber polysulphone reinforcement was 14,106 MPa and the flexural strength 546.6 MPa. The flexural modulus of conventional denture-base resin was 1746 MPa, reinforcement increased it to 2328 MPa, and the flexural strength increased from 164 MPa to 209 MPa. The flexural modulus of high impact polymer was 1684 MPa and reinforcement increased it to 2067 MPa. The flexural strength was increased from 171 MPa to 242 MPa with reinforcement. Statistical analysis using t test showed that reinforcement affected the flexural modulus and flexural strength of polymer brands (p < : 05). Conclusion: Novel glass fiber polysulphone composite reinforcement may considerably enhance the flexural properties of multi phase denture-base polymers. Dissertation (MSc (Prosthetic Dentistry))--University of Pretoria, 2005. Prosthodontics unrestricted

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Thokoane, Meriting Gladys. "The dimensional distortion of acrylic resin denture bases subjected to different dual cure materials and methods." Thesis, 2013. http://hdl.handle.net/10539/15490.

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A research report submitted to the School of Oral Health Science, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Dentistry in the field of Prosthodontics. Johannesburg, 2013 Background: The majority of edentulous patients are unable to afford anything other than mucosa-borne complete dentures, but the conventional methods of complete denture fabrication can be lengthy and expensive. Simplified techniques have been proposed to reduce the number of clinical visits as well as the laboratory time and costs. One such technique has advocated making the final heat-cured acrylic resin denture base after the first visit, which then requires a second processing cure for the artificial teeth. This dual-cure has been reported to cause distortion of the previously cured denture base. Purpose: To measure the amount of linear and three-dimensional distortion of an acrylic resin maxillary denture base following an additional curing cycle using different processing methods. Method and Materials: A standardised method was developed for fabricating a maxillary denture base with measuring pins , as well as a standardised method for waxing an arch of teeth to the base. The pins were used to make three-dimensional measurements using a Reflex Microscope. The resins used were from the same manufacturer. Four dual cure methods of varying temperature and time were used: 1. Place flask in boiling water for 20 minutes, remove and plunge into cold water for 20 minutes; 2. Place into cold water, heat up to 70°C, leave for 1 hour, remove and bench cool; 3. Place into cold water, bring to 72°C for 8 hours and bench cool; and 4. Place in cold water, bring to the boil for 40 minutes, bench cool for 45 minutes, then plunge into cold water for 20 minutes. For each method five models were fabricated, to give a total of 20 models. Results: Although there was an overall distortion of all denture bases following a second cure, the linear and 3D differences were not statistically significant between and within the different dual cure methods tested. The mean percentage changes measured were translated into real changes in distances or angles between the pins, in order to ascertain the clinical relevance of these changes, for if they are too great, the distortion of the denture base will exceed the resilience of the mucosa as well as disrupt the peripheral seal, and the denture base will not be retentive. The largest mean change was seen in the three-dimension distance between the innermost pins in the posterior palate, but this was only 1.3mm. This also showed the worst change of all measurements, but it was still only 2.0mm. Conclusions: With the adaptive nature of the denture-supporting tissues, the changes described are unlikely to have any clinical significance. Although only one brand of denture base resin was used, it is representative of the modern rapid-cure resins, and so rapid cure methods can be advocated when a dual cure is required.

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Kiilu, Paul Muli. "An in vitro investigation of the flexural strength and microstructure of "stick glass fiber" and "wire mesh" reinforced heat cured denture base acrylic." Thesis, 2008. http://hdl.handle.net/10321/446.

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Submitted in fulfillment of the Degree of Master in Technology: Dental Technology in the Department of Dental Services Faculty of Health Sciences, Durban University of Technology, 2008. Globally in the field of Dental Technology, polymethyl methacrylate (PMMA) resin continues to be the popular material for the fabrication of denture bases in removable prosthodontics. However, the mechanical strength of the denture base is a concern due to fractures occurring intra-orally or when accidentally dropped. The objective of this in vitro investigation was therefore to evaluate and compare the flexural strength and microstructure of stick® glass fibre and wire mesh reinforced PMMA resin after thermocycling. The selection of the materials used in this study was based primarily on their popularity and availability in South Africa. These materials were selected to ensure that the results of this study would have further implicational value in the commercial dental industry when published. This investigation was conducted by means of fabricating a total of 90 PMMA resin specimens and divided in three groups consisting of 30 specimens each. Sample groups 1 and 2 were reinforced with stick® glass fibres and wire mesh respectively. The un-reinforced sample group was the control. All 90 specimens were thermocycled in water at temperatures between 5˚C and 55˚C for 2100 cycles. The flexural strength of each specimen was tested using a universal testing machine and the microstructure of the fractured surfaces was then analysed using scanning electron microscopes (SEM). SPSS version 15.0 was used for data analysis. A p-value of <0.05 was considered as statistically significant. Data were analysed using parametric and non-parametric statistical methods. Statistically significant differences in flexural strength existed between the three sample groups (p<0.001) with the stick® glass fibre and wire mesh sample groups being significantly superior to the control. Furthermore there was a significant association between fracture modes and sample groups. Microscopic analysis revealed the presence of voids. Statistically, in terms of microstructure (% of voids present), a significant difference existed between all sample groups. With regards to surface texture of the compression and tension sides of the test specimens, significant differences existed between the three sample groups. Furthermore microscopic analysis revealed partial impregnation and distribution of the fibres to the PMMA resin matrix and un-bonding between the wire mesh and PMMA resin matrix. Statistically, the Mann-Whitney test was conducted to compare flexural strength between sample groups with and without voids. The flexural strength was higher in sample groups with voids than those without. This is an important finding from the clinical perspective because, in some structures of dentures, toughness is a desired property. Nevertheless in order to find the long-term data especially on clinical behaviour of these new fibre reinforcement systems, more studies should be conducted.

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Viegas, Olavo Guerreiro. "Analysis of the Interface between calcium silicate-based endodontic materials and root canal dentine: a pilot study." Master's thesis, 2013. http://hdl.handle.net/10316/36557.

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Trabalho final do 5º ano com vista à atribuição do grau de mestre no âmbito do ciclo de estudos de Mestrado Integrado em Medicina Dentária apresentado à Faculdade de Medicina da Universidade de Coimbra. This study evaluated by scanning electron microscopy the interface between calcium silicate-based endodontic materials (MTA and Biodentine™) and root canal dentine using three different irrigation protocols. Root canals of 66 human teeth were subjected to biomechanical preparation with ProTaper rotary instruments up to a finish file F4. The teeth were assigned into six groups according to the irrigation protocol and obturation material employed: 1A. NaOCl + MTA; 1B. NaOCl + Biodentine ™; 2A. NaOCl/NaCl/EDTA + MTA; 2B. NaOCl/NaCl/EDTA + Biodentine™; 3A. NaOCl/NaCl/CHX + MTA; 3B. NaOCl/NaCl/CHX + Biodentine™. After obturation teeth were stored for 5 days at 37⁰C in a moist environment to allow the set of sealers. One section of 3mm thick was obtained from the apical third. The specimens were immersed in PBS for 5 days. After this period of time, one specimen of each group was sectioned longitudinally into two symmetrical pieces. One of the two halves - the one with the material - was processed for morphological observation, element mapping and chemical analysis along the dentine-material interface using SEM and EDS. Along the material-dentine interface, both materials formed a tag-like structure that was more evident in groups where EDTA was used for final irrigation protocol. Apatite crystal formation was visible along the interface and within the interfacial dentine in all groups. The Ca depth was constantly larger than the Si depth but the uptake of Si was more prominent in all groups for Biodentine™. Both Biodentine™ and MTA caused the uptake of Ca and Si in the adjacent root canal dentine in the presence of PBS. The dentine element uptake for Si was more prominent in Biodentine™ than in MTA.

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Dissertations / Theses on the topic 'Denture Base Material'

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