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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Numerical Prediction of Panel Dent Resistance Incorporating Panel Forming Strains

Thomas, Dylan January 2001 (has links)
This thesis presents a numerical method of predicting both static and dynamic denting phenomena in automotive body panels. The finite element method is used as a predictive tool to assess panel performance prior to production of tooling. A custom software package has been developed to transform existing finite element forming models into ready-to-run finite element denting models, minimising the effort required to perform dent simulations. Over 50 multi-step finite element models were performed. Each of these models simulated the forming, springback and subsequent denting of either 1. 05mm thick AA5754, or0. 81mm, 0. 93mm or 1. 00mm thick AA6111 aluminum sheet. Experimental validation of dent predictions using this method has shown that the trends in both static and dynamic dent resistance have been captured quite well. These validation studies demonstrated the sensitivity of the results to various parameters such as panel thickness, pre-strain, curvature and thickness, as well as numerical formulation parameters. It has been determined that it is particularly important to use forming data within the denting models for accurate results to be obtained.
82

The Numerical Prediction of the Dent Resistance of Aluminum Structural Panel Assemblies

Hodgins, Blake January 2001 (has links)
An examination of static and dynamic dent resistance of structural panel assemblies representing automotive hoods is described in this thesis. Fabricated panel assemblies incorporating typical components of real automotive parts were tested. The panel assemblies included an AA5754 inner panel using an array of teacup supports and an AA6111 closure panel joined with automotive mastic. The assemblies allowed for parametric assessment of numerous factors affecting dent resistance including: panel thickness, panel curvature, panel support configuration and dent site location. An extensive experimental program evaluated various panel combinations under both static and dynamic denting conditions. The measured results illustrate various trends of the different factors affecting dent resistance. The experimental database allows a qualitative assessment of dent resistance for full-scale automotive parts. The importance of support conditions is highlighted. The influence of mastic thickness is found to be a critical consideration. Numerical simulations of the dent test were undertaken using finite element techniques. The numerical predictions offer varying degrees of accuracy. The quantitative results are limited, due to numerical concerns, but the qualitative trends are generally well captured. As well, the relative importance of the various parametric factors is well represented in the numerical results. The interaction of the components at the teacup supports proved to critical to the predictive ability of the models. The method developed to model the interaction was somewhat limited by the available material models within the numerical code used, but offers promise for improved results in future simulations. The modelling method is readily transferred to full-scale automotive panels for assessment of dent resistance early in the design cycle.
83

Indentation and Wear Behavior of Superelastic TiNi Shape Memory Alloy

Neupane, Rabin 28 March 2014 (has links)
TiNi shape memory alloy is characterized by shape memory and superelastic effects which occur due to reversible martensite transformation. It has been recently found that TiNi alloy has superior dent and wear resistance compared to other conventional materials. The stress-induced martensite transformation exhibited by this alloy contributes to its dent and wear resistance. Much work is required to establish the fundamental principals governing the superelastic behavior of TiNi under wear and indentation conditions. Understanding the superelastic behavior helps to employ superelastic TiNi in applications where high impact loading is expected as in gears and bearings. In this study the superelastic behavior of shape memory alloys under reciprocating sliding wear and indentation loading conditions was investigated. The deformation behavior of superelastic Ti-Ni alloys was studied and compared to AISI 304 stainless steel. Dominant wear and deformation mechanisms were identified.
84

A??o antimicrobiana dos extratos de Turnera ulmifolia linn e Passiflora edulis flavicarpa degener frente a bact?rias bucais do g?nero Streptococcus e microrganismos superinfectantes

Mendon?a, Ang?lica Kercya Pereira de 25 July 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-01-16T19:16:33Z No. of bitstreams: 1 AngelicaKercyaPereiraDeMendonca_DISSERT.pdf: 1253602 bytes, checksum: 20cdc99a948ce77b5113a3d59ba2e556 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-01-22T13:06:34Z (GMT) No. of bitstreams: 1 AngelicaKercyaPereiraDeMendonca_DISSERT.pdf: 1253602 bytes, checksum: 20cdc99a948ce77b5113a3d59ba2e556 (MD5) / Made available in DSpace on 2018-01-22T13:06:34Z (GMT). No. of bitstreams: 1 AngelicaKercyaPereiraDeMendonca_DISSERT.pdf: 1253602 bytes, checksum: 20cdc99a948ce77b5113a3d59ba2e556 (MD5) Previous issue date: 2017-07-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O controle qu?mico do biofilme dent?rio e da microbiota planct?nica atua como coadjuvante do controle mec?nico para fins de manuten??o e/ou restabelecimento da sa?de bucal. Nesse contexto, emergem os fitoter?picos com a finalidade de atuar como agentes antimicrobianos na cavidade oral. Diante disso, o presente estudo buscou avaliar a a??o antimicrobiana dos extratos da folha e da raiz da Turnera ulmifolia Linn. (chanana) e da folha da Passiflora edulis Flavicarpa Degener (maracuj?-amarelo) frente a bact?rias do g?nero streptococcus (Streptococcus mutans, Streptococcus oralis e Streptococcus sanguinis) e microrganismos superinfectantes (Pseudomonas aeruginosa e Enterococcus faecalis) do ambiente bucal. Para isso foram investigadas a Concentra??o Inibit?ria M?nima (CIM), a Concentra??o Inibit?ria M?nima de Ader?ncia (CIMA) e a Cin?tica Bactericida dos extratos mencionados, utilizando como controle o digluconato de clorexidina a 0,12%. No que diz respeito ? atividade inibidora de crescimento bacteriano dos extratos investigados, verificou-se que frente ao Streptococcus mutans, o extrato da folha da Turnera ulmifolia Linn se apresentou estatisticamente superior aos demais (p<0,05); com rela??o aos Streptococcus oralis e Streptococcus sanguinis, foi o extrato da folha da Passiflora edulis Flavicarpa Degener que exibiu resultados com signific?ncia estat?stica (p<0,05) e diante dos microrganismos superinfectantes, foi o extrato da raiz da Turnera ulmifolia Linn que apresentou os melhores resultados (p<0,05). Esses extratos vegetais mostraram halos de inibi??o variados, apresentando at? 22mm de di?metro. No tocante ao efeito antiaderente, todos os extratos testados apresentaram resultados positivos em diferentes dilui??es, para todos os microrganismos estudados, merecendo destaque apenas o efeito antiaderente do extrato da folha da Passiflora edulis Flavicarpa Degener frente aos Streptococcus oralis e Streptococcus sanguinis. Quanto ? Cin?tica Bactericida, os extratos bruto e dilu?dos testados n?o demonstraram atividade inibidora de crescimento bacteriano a partir de 4h de contato com nenhum dos microrganismos do estudo. Por?m, o digluconato de clorexidina a 0,12% se mostrou mais eficaz do que todos os referidos extratos para todos os testes realizados, exceto para o efeito antiaderente do extrato da folha da Passiflora edulis Flavicarpa Degener frente aos Streptococcus oralis e Streptococcus sanguinis, sendo esses ?ltimos superiores ao digluconato de clorexidina a 0,12%. Portanto, conclui-se que os extratos vegetais apresentam atividade inibidora de crescimento bacteriano, efeito antiaderente e potencial bactericida inferiores ao digluconato de clorexidina a 0,12% frente a todos os microrganismos estudados, exce??o feita somente ao efeito antiaderente do extrato da Passiflora edulis Flavicarpa Degener com rela??o aos Streptococcus oralis e Streptococcus sanguinis que parece ser superior ?quele do digluconato de clorexidina a 0,12% para os extratos investigados. / The chemical control of the dental biofilm and the planktonic microbiota acts as a coadjuvant of the mechanical control for maintenance and / or restoration of oral health. In this context, phytotherapics emerge with the purpose of acting as antimicrobial agents in the oral cavity. Therefore, the present study aimed to evaluate the antimicrobial action of leaf and root extracts of Turnera ulmifolia Linn (Chanana) and the leaf of the Passiflora edulis Flavicarpa Degener (yellow passion fruit) against bacteria of the genus Streptococcus mutans, Streptococcus oralis and Streptococcus sanguinis and superinfecting microorganisms (Pseudomonas aeruginosa and Enterococcus faecalis) from the oral environment. For this purpose, the Minimal Inhibitory Concentration (MIC), Minimum Inhibitory Adhesion Concentration (MIAC) and Bactericidal Kinetics of the mentioned extracts were investigated using 0,12% chlorhexidine digluconate as the control. As regards the bacterial growth inhibitory activity of the extracts investigated, it was verified that, in relation to Streptococcus mutans, Turnera ulmifolia Linn leaf extract was statistically superior to the others (p<0,05), in relation to Streptococcus oralis and Streptococcus sanguinis, was the extract of the leaf of the Passiflora edulis Flavicarpa Degener that showed results with statistical significance (p<0,05) and in front of the superinfecting microorganisms, was the root extract of Turnera ulmifolia Linn that presented the best results (p<0,05). These plant extracts showed varied inhibition halos, presenting up to 22mm in diameter. Regarding the anti-adherence effect, all the extracts tested showed positive results at different dilutions for all the microorganisms studied, with emphasis only on the non-stick effect of Passiflora edulis Flavicarpa Degener leaf extract against Streptococcus oralis and Streptococcus sanguinis. Regarding Bactericidal Kinetics, the crude and diluted extracts tested did not demonstrate bacterial growth inhibitory activity after 4 hours of contact with any of the microorganisms in the study. However, the chlorhexidine digluconate 0,12% was more effective than all the extracts for all tests, except for the non-stick effect of Passiflora edulis Flavicarpa Degener leaf extract front of Streptococcus oralis and Streptococcus sanguinis, and those higher than the 0,12% chlorhexidine digluconate. Therefore, it is concluded that plant extracts presents inhibitory activity of bacterial growth, non-stick effect and bactericidal potential lower than the 0,12% compared chlorhexidine gluconate to all microorganisms studied, except only to the non-stick effect of the extract of Passiflora edulis Flavicarpa Degener with respect to Streptococcus oralis and Streptococcus sanguinis which appears to be superior to that of the 0,12% chlorhexidine digluconate for the investigated extracts.
85

Influ?ncia da coes?o/adaptabilidade familiar, de fatores sociodemogr?ficos e comportamentais na preval?ncia de c?rie dent?ria em pr?-escolares / Influence of family cohesion/adaptability, sociodemografics and behavioral factors in the prevalence of dental caries in preschool children

Alencar, Bruna Mota de 09 July 2015 (has links)
Submitted by Nivaldo Melo (nivaldo.melo@ufvjm.edu.br) on 2015-11-27T22:07:18Z No. of bitstreams: 2 bruna_mota_alencar.pdf: 1299407 bytes, checksum: 68d1fc673481812ec5ce638730779149 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-12-02T11:25:15Z (GMT) No. of bitstreams: 2 bruna_mota_alencar.pdf: 1299407 bytes, checksum: 68d1fc673481812ec5ce638730779149 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Made available in DSpace on 2015-12-02T11:25:16Z (GMT). No. of bitstreams: 2 bruna_mota_alencar.pdf: 1299407 bytes, checksum: 68d1fc673481812ec5ce638730779149 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Previous issue date: 2015 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A qualidade emocional das rela??es familiares pode afetar os comportamentos de sa?de bucal. Os estudos que investigaram fatores familiares associados ? sa?de bucal n?o aprofundaram em quest?es psicossociais. A compreens?o dessa associa??o pode indicar os caminhos para promo??o de sa?de, enfatizando a necessidade de a??es multidisciplinares, melhorando, assim, a sa?de bucal da popula??o. Particularmente em crian?as pr?-escolares, que dependem do cuidado de sua fam?lia, a investiga??o da influ?ncia de fatores psicossociais familiares sobre a preval?ncia de doen?a bucal ? importante. Assim, o objetivo desse estudo foi avaliar a influ?ncia da coes?o/adaptabilidade familiar, de fatores sociodemogr?ficos e de comportamentos relacionados ? sa?de bucal sobre a preval?ncia de c?rie dent?ria n?o tratada em crian?as pr?-escolares. Para isso, uma amostra representativa de 461 crian?as foi recrutada em creches e pr?-escolas na cidade de Diamantina, Brasil. A presen?a de c?rie n?o tratada foi detectada pelos crit?rios do Sistema Internacional de Avalia??o e Detec??o de C?rie (International Caries Detection and Assessment System- ICDAS II). Informa??es sociodemogr?ficas, tais como caracter?sticas da crian?a, escolaridade materna, renda e n?mero de pessoas que vivem da renda, bem como informa??es relacionadas a comportamentos de sa?de bucal tamb?m foram investigadas. A coes?o/adaptabilidade familiar foi investigada por meio do Family Adaptability and Cohesion Evaluation Scale (FACES III) que classifica as fam?lias, de acordo com o seu funcionamento, em balanceadas, moderadamente balanceadas e n?o balanceadas. An?lise descritiva e modelo de regress?o de Poisson foram utilizados para an?lise dos dados. A preval?ncia de c?rie n?o tratada foi de 30,6%. A An?lise multivariada mostrou que crian?as que pertenciam a fam?lias n?o balanceadas, classificadas de acordo com o FACES III, tinham maior preval?ncia de les?es n?o tratadas de c?rie dent?ria (RP: 1,49; IC95%: 1,01-2,20; p= 0.045). Al?m disso, rendas familiares de dois a menos de cinco sal?rios m?nimos ( RP: 2,80; IC95%: 1,16-6,75; p=0 .021), de um a menos de dois sal?rios m?nimos (RP: 4,15; IC95%: 1,73-9,85; p= 0.001) e menor do que um sal?rio m?nimo (RP: 4,07; IC95%: 1,65-10,00; p= 0.002) tamb?m foram associadas com a presen?a de les?es n?o tratadas de c?rie dent?ria em crian?as pr?-escolares. Concluiu-se que crian?as pr?-escolares de fam?lias n?o balanceadas tinham maior preval?ncia de c?rie dent?ria n?o tratada. Al?m disso, menores rendas familiares foram fatores de risco para a presen?a de c?rie n?o tratada em crian?as pr?-escolares. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Odontologia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2015. / ABSTRACT The emotional quality of family relationships can affect the behaviors related to oral health. Studies investigating family factors associated with oral health have not deepened in the psychosocial issues. The understanding of this association can indicate the pathways to health promotion, emphasizing the necessity of multidisciplinary actions to improve oral health in the population. Especially in preschool children, which depend on the care of their family, the investigation of family-related psychosocial factors and the occurrence of oral disease is important. Thus, the objective of this study is to evaluate the influence of familiar cohesion/adaptability, sociodemographic factors and of behaviors related to oral heath on the prevalence of untreated dental caries in preschool children. For this, a representative sample of 461 children were recruited in day care centre/preschools in the city of Diamantina, Brazil. The presence of untreated caries were detected by the International Caries Detection and Assessment System (ICDAS II) criteria. Sociodemografic information, such as children characteristics, maternal level of education, income and number of people living of the same income, as well as information related to oral health behavior were also investigated. The family cohesion/adaptability was investigated by the Family Adaptability and Cohesion Evaluation Scale (FACES III) which classifies the families according to their functioning, in balanced, moderately balanced, and not balanced. Descriptive analyses and Poisson regression models were used to analyze the data. The prevalence of untreated dental caries was of 30,6%. The multivariate analyses showed that children belonged to unbalanced families, classified according to FACES, had a greater frequency of untreated dental caries (1,01-2,20; p=0.045). Furthermore, family income from 2 to less than 5 minimum salaries (RP:2,80; IC 95%:1,16-6,75; p=0.021), from one to two minimum salaries (RP: 4,15; IC95%: 1,73-9,85; p= 0.001) and less than one minimum salary (RP: 4,07; IC95%: 1,65-10,00; p= 0.002) were also associated with the presence of untreated caries lesions in preschool children. In conclusion, preschool children of unbalanced families had greater untreated dental caries prevalence. Futhermore, smaller family incomes were pointed as risk factors for presence of untreated caries in preschool children. Keywords: dental caries, preschools children, family functioning.
86

Impacto da c?rie dent?ria na qualidade de vida de crian?as de 1 a 3 anos de idade e de suas fam?lias / Impact of dental caries on quality of life of babies between 1 and 3 years old and their families

Fernandes, Izabella Barbosa January 2014 (has links)
?rea de concentra??o: Odontopediatria. / Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-12-22T13:35:04Z No. of bitstreams: 2 izabella_barbosa_fernandes.pdf: 2088859 bytes, checksum: 015e8cf831539e0c08c0656e3ff8e95e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-12-22T13:35:37Z (GMT) No. of bitstreams: 2 izabella_barbosa_fernandes.pdf: 2088859 bytes, checksum: 015e8cf831539e0c08c0656e3ff8e95e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2015-12-22T13:35:37Z (GMT). No. of bitstreams: 2 izabella_barbosa_fernandes.pdf: 2088859 bytes, checksum: 015e8cf831539e0c08c0656e3ff8e95e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014 / A c?rie dent?ria n?o tratada ? a condi??o bucal mais frequentemente associada com um impacto negativo na qualidade de vida de crian?as por estar associada ? dor, desconforto, dificuldades na mastiga??o, problemas de fala, dist?rbios no sono, problemas psicol?gicos, dificuldades na escola e dificuldades na intera??o social da crian?a. Essa associa??o tem sido frequentemente verificada em adultos, adolescentes, crian?as escolares e pr?-escolares. A associa??o de impacto da c?rie dent?ria em beb?s sobre a qualidade de vida ? ainda desconhecida. O objetivo deste estudo foi avaliar o impacto de diferentes est?gios de progress?o da c?rie dent?ria na qualidade de vida de beb?s e de suas fam?lias na cidade de Diamantina, Minas Gerais. Uma amostra de 308 beb?s de 1 a 3 anos de idade foi submetida a um exame cl?nico para avaliar a c?rie dent?ria atrav?s do Sistema Internacional de Avalia??o e Detec??o de C?rie - International Caries Detection and Assessment System (ICDAS). As m?es dos beb?s foram convidadas a responder dois question?rios: um sobre qualidade de vida relacionada ? sa?de bucal (QVRSB) das crian?as e de suas fam?lias, o Brazilian Early Childhood Oral Health Impact Scale (B-ECOHIS) e outro sobre as caracter?sticas e condi??es sociodemogr?ficas dos beb?s e de suas fam?lias. A an?lise estat?stica foi realizada atrav?s do programa SPSS - Statistical Package for Social Sciences (SPSS for Windows, version 20.0, SPSS Inc. Chicago, IL, USA) e envolveu an?lise descritiva, os testes Kappa, Kruskal Wallis, Mann-Whitney e modelos de regress?o de Poisson hierarquicamente ajustados. A preval?ncia de c?rie n?o tratada foi de 64,3%. A maioria dos beb?s com c?rie apresentava c?rie em seu est?gio severo de progress?o (53,5%). Houve uma diferen?a significativa entre o est?gio de progress?o da c?rie e QVRSB no beb? e na fam?lia. O est?gio severo de c?rie dent?ria [RP IC95%= 2.80 (1.90-4.12)] e a menor idade da m?e [RP IC95%= 1.69 (1.27-2.25) foram associados com o maior impacto na qualidade de vida. Concluiu-se que les?es de c?rie em est?gios mais avan?ados de progress?o foram associados a uma pior qualidade de vida em beb?s e em suas fam?lias. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2014. / ABSTRACT Untreated dental caries is the most often oral condition associated with negative impact on quality of life in children by being associated with pain, discomfort, difficulty in chewing, speech problems, sleep disorders, psychological problems, difficulties in school and social interaction of the child. This association has been frequently seen in adults, adolescents, school children and preschoolers. The impact of dental caries in the quality of life of babies still unknown. The aim of this study was to evaluate the impact of different stages of progression of dental caries in the quality of life of babies and their families in Diamantina, Minas Gerais. A sample of 308 babies aged 1-3 years old underwent a clinical examination to assess dental caries through the International Caries Detection and Assessment System (ICDAS). Parents of babies were asked to answer two questionnaires: one about oral health related quality of life (OHRQoL) of children and their families using the Brazilian Early Childhood Oral Health Impact Scale (B-ECOHIS) and another about sociodemographic characteristics and conditions of babies and their families. Statistical analysis was performed using SPSS - Statistical Package for Social Sciences (SPSS for Windows, version 20.0, SPSS Inc. Chicago, IL, USA) and involved descriptive analysis, Kappa, Kruskal-Wallis and Mann-Whitney test and Poisson model regression adjusted hierarchically. The prevalence of untreated dental caries was 64.3%. Most babies with caries had caries in severe progression stage (53.5%). There was a significant difference between the stage of caries progression and OHRQoL on babies and their families. Severe stage of dental caries [OR = 2.80 95% CI (1.90-4.12)] and lower mother's age [OR = 1.69 95% CI (1:27 to 2:25) were associated with the greatest impact on quality of life. It was concluded that dental caries in more advanced stages of progression were associated with worse quality of life in babies and their families.
87

Avalia??o in vitro do comportamento mec?nico de pr?teses totais fixas sobre implantes em mand?bula ed?ntula ? conceito all-on-four

Fonseca, Dimitri Ribas 10 February 2012 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-10-23T11:18:19Z No. of bitstreams: 2 Dimitri_ Ribas_Fonseca.pdf: 1486448 bytes, checksum: 134a8204530bf086edcbf7b26f37a0bf (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-10-23T11:20:39Z (GMT) No. of bitstreams: 2 Dimitri_ Ribas_Fonseca.pdf: 1486448 bytes, checksum: 134a8204530bf086edcbf7b26f37a0bf (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Made available in DSpace on 2015-10-23T11:20:39Z (GMT). No. of bitstreams: 2 Dimitri_ Ribas_Fonseca.pdf: 1486448 bytes, checksum: 134a8204530bf086edcbf7b26f37a0bf (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Previous issue date: 2012 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / O conceito all-on-four apresenta sucesso cl?nico longitudinal. Entretanto, diferentes estudos mencionaram o uso de pr?teses fixas provis?rias totalmente acr?licas para a fase prot?tica inicial, possibilitando a ocorr?ncia de complica??es mec?nicas de 11% a 30%. Alguns achados relatam a aplica??o de alta tecnologia para elabora??o do refor?o da pr?tese provis?ria como o sistema CAD-CAM e soldas intrabucais para minimizar as falhas prot?ticas. Em uma abordagem que utiliza princ?pios j? fundamentados e ainda n?o agregados conjuntamente em uma mesma proposta prot?tica, este estudo avaliou uma pr?tese com infraestrutura met?lica sem soldas apoiada sobre cilindros pr?-fabricados. Dois desenhos de pr?teses acr?licas, representativas para o conceito all-on-four, com configura??es inovadoras foram consideradas para avalia??o. Para refer?ncia, foram produzidos dois grupos controle, G1 (controle negativo, n=10) e G4 (controle positivo, n=10). Os grupos de estudo foram G2 (grupo teste 2, n=10) e G3 (grupo teste 3, n=10). Todos os corpos de prova foram submetidos ? ciclagem t?rmica com 500 ciclos (5?C,?2? por 30s e 55?C,?2? por 30s). Em sequ?ncia, G2 e G4 foram avaliados quanto ? adapta??o sob microscopia eletr?nica de varredura e os quatro grupos foram submetidos ao ensaio flexural sobre o cantilever. Os resultados tiveram an?lise estat?stica descritiva, avalia??o da distribui??o da amostra pelo teste de Shapiro-Wilk, an?lise de vari?ncia de Kruskal-Wallis e compara??o intergrupo pelo teste de Mann-Whitney. O grupo G2 apresentou menor m?dia de desadapta??o (30,02 ?m) em compara??o ao grupo G4 (79,42 ?m), com diferen?a significativa (P<0,05). Tamb?m foram significativas (p<0,01) as avalia??es dos resultados do teste mec?nico. O grupo G4 apresentou maior m?dia de resist?ncia ? fratura em resina (943,97N), seguido pelos grupos G3 (830,50N), G2 (657,50N) e G1 (403,58N). Os significantes resultados da avalia??o flexural e de adapta??o para a infraestrutura met?lica sem soldas sugerem continuidade na avalia??o desta modalidade prot?tica. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Odontologia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2012. / ABSTRACT The all-on-four concept presents high success rates of clinical follow-up studies. However, different studies select fully acrylic provisional bridges for prosthetic initial phase, allowing the incidence of mechanical complications from 11% to 30%. Studies reported the application of high technology to prepare the prosthetic framework such as CAD-CAM systems and intraoral welding, to minimize the failures. In an approach that uses known principles and has not added together in the same way, this study evaluated prosthesis with a metal framework without welding supported by prefabricated cylinders. Two acrylic prosthesis design, representative for the All-on-four, with a new configurations were selected for this study. Two control groups were produced G1 (negative control, n=10) and G4 (positive control, n=10). The study group were the G2 (test group 2, n=10) and G3 (test group 3, n=10). The sample was subjected to thermal cycling at 500 cycles (5?C,?2? at 30s e 55?C,?2? at 30s). In the segment, G2 and G4 were evaluated for misfit under scanning electron microscopy and the four groups were subjected to flexural test on the cantilever. Descriptive statistical analysis was performed and an evaluation of the sample distribution by the Shapiro-Wilk test. The Kruskal-Wallis and Mann-Whitney tests were used to compare groups. The group G2 had lower average misfit (30.02 ?m) compared to G4 (79.42 ?m), with significant difference (p<0.05). Were also significant (p<0.01) the results of the mechanical test. The G4 showed higher mean fracture toughness resin (943.97N), followed by G3 (830.50N), G2 (657.50N) and G1 (403.58N). The significant results of the flexural test and misfit evaluation for metal framework without welding, suggest continuity in the evaluation of this prosthesis.
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Altera????o da cor, rugosidade e massa de tecidos dent??rios promovida por dentifr??cios para hipersensibilidade associados a agentes branqueadores A

Lima, Max Jos?? Pimenta 19 June 2018 (has links)
Submitted by Carla Santos (biblioteca.cp2.carla@bahiana.edu.br) on 2018-11-12T19:00:45Z No. of bitstreams: 1 ALTERA????O DA COR, RUGOSIDADE E MASSA DE TECIDOS DENT??RIOS PROMOVIDA POR DENTIFR??CIOS PARA HIPERSENSIBILIDADE ASSOCIADOS A~1.pdf: 2286328 bytes, checksum: 231dfddcff6d3a0e2fd3d391529275a5 (MD5) / Approved for entry into archive by JOELMA MAIA (ebmsp-bibliotecacp2@bahiana.edu.br) on 2018-11-12T19:45:30Z (GMT) No. of bitstreams: 1 ALTERA????O DA COR, RUGOSIDADE E MASSA DE TECIDOS DENT??RIOS PROMOVIDA POR DENTIFR??CIOS PARA HIPERSENSIBILIDADE ASSOCIADOS A~1.pdf: 2286328 bytes, checksum: 231dfddcff6d3a0e2fd3d391529275a5 (MD5) / Made available in DSpace on 2018-11-12T19:45:30Z (GMT). No. of bitstreams: 1 ALTERA????O DA COR, RUGOSIDADE E MASSA DE TECIDOS DENT??RIOS PROMOVIDA POR DENTIFR??CIOS PARA HIPERSENSIBILIDADE ASSOCIADOS A~1.pdf: 2286328 bytes, checksum: 231dfddcff6d3a0e2fd3d391529275a5 (MD5) Previous issue date: 2018-06-19 / Objetivo: Avaliar a altera????o de cor, rugosidade e massa de tecidos dent??rios bovinos submetidos ?? escova????o simulada com dentifr??cios para hipersensibilidade dentin??ria associado ou n??o a agentes branqueadores. M??todos: Foram preparados 120 corpos de prova obtidos de incisivos bovinos, divididos em 2 grupos: Grupo Esmalte (n=60) e Grupo Dentina (n=60). Os grupos foram subdivididos em 6 subgrupos (n=10) de acordo com o tratamento: Grupo Controle Negativo (GCN - ??gua), Grupo Controle Positivo (CGP - Colgate Total 12), Grupo Teste 1 (GT1 - Colgate Sensitive Pr??-al??vio), Grupo Teste 2 (GT2 - Colgate Sensitive Pr??-al??vio Real White), Grupo Teste 3 (GT3 - Sensodyne R??pido Al??vio), Grupo Teste 4 (GT4 - Sensodyne True White). No teste de abras??o, foram realizados 100.000 ciclos equivalentes a 24 meses de escova????o simulada, com intervalos de 6, 12 e 24 meses. A an??lise da altera????o de cor, rugosidade superficial e massa foram realizadas antes da escova????o simulada e nos seus intervalos. A avalia????o da rugosidade superficial foi realizada em quatro diferentes dire????es atrav??s de leitura em rugos??metro, a altera????o de cor foi obtida por espectrofot??metria (CIE L*a*b*) e a varia????o de massa (g) foi obtida em triplicata utilizando-se balan??a de precis??o. Resultados: No Grupo Esmalte, ao final dos 24 meses, houve redu????o na intensidade da pigmenta????o dos esp??cimes, principalmente aos 6 meses. A varia????o da rugosidade foi estatisticamente significativa aos 6 meses em todos os subgrupos esmalte quando comparados com o GCN, e aos 24 meses todos os subgrupos apresentaram superf??cies mais polidas e perda de massa estatisticamente significante. No Grupo Dentina, ao final dos 24 meses, houve um aumento da varia????o da rugosidade e da perda de massa, contudo n??o houve diferen??a estatisticamente significante entre os subgrupos quanto ?? rugosidade, mas a perda de massa foi estatisticamente significante quando comparados ao GCN. A Microscopia Eletr??nica de Varredura demonstrou que os canal??culos dentin??rios foram obliterados parcialmente em todos subgrupos dentina. Conclus??o: Os dentifr??cios para hipersensibilidade, associados ou n??o a agentes branqueadores, foram capazes de remover manchas superficiais no esmalte bovino e promoveram perda de massa tanto no esmalte como na dentina, polimento superficial do esmalte e aumento da rugosidade na dentina, com oblitera????o parcial dos canal??culos dentin??rios.
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Les phosphoprotéines sécrétées liant le calcium (SCPP) impliquées dans la formation de l'émail dentaire : expression chez le lézard Anolis carolinensis et évolution chez les amniotes / Secretory calcium-binding phosphoproteins (SCPP) involved in enamel formation : expression in the lizard Anolis carolinensis and evolution in amniotes

Gasse, Barbara 14 April 2015 (has links)
La formation de l'émail dentaire met en jeu des phosphoprotéines sécrétées liant le calcium. Parmi celles-ci figurent amélogénine (AMEL), améloblastine (AMBN) et énaméline (ENAM), qui ont fait l'objet de nombreuses études chez les mammifères. Plus récemment, une quatrième protéine de la même famille a été découverte, l'amélotine (AMTN). Elle n'a été étudiée que chez les rongeurs et son rôle au cours de l'amélogenèse reste mal défini. L'objectif de cette thèse est d'élargir les connaissances sur AMTN en étudiant son évolution chez les amniotes et son expression au cours de l'amélogenèse chez le lézard Anolis carolinensis. Les séquences d'AMTN d'un grand nombre d'amniotes ont été extraites des bases de données ou obtenues par PCR, et analysées. Ces analyses ont mis en évidence différentes structures géniques et des acides aminés très conservés au cours de l'évolution. Cette conservation indique qu'ils sont essentiels à la structure ou à la fonction de la protéine. L'expression d'AMTN ainsi que celle d'AMEL, AMBN et ENAM ont été étudiées par hybridation in situ sur des coupes de mâchoires de lézard. La comparaison des patrons d'expression chez le lézard avec ceux décrits chez la souris a révélé des différences dans l'expression spatio-temporelle d'AMTN. De ce fait, afin de mieux comprendre l'évolution de ce gène, son expression a été étudiée chez un amphibien (Pleurodeles waltl) et un marsupial (Monodelphis domestica).Ces travaux suggère un lien entre l'évolution de la structure génique d'AMTN (perte d'exons et de domaines fonctionnels) et de son expression (précoce versus tardive) avec l'émergence de la structure prismatique de l'émail chez les mammifères. / Enamel formation requires the involvement of secretory calcium-binding phosphoproteins. Three of them, amelogenin (AMEL), ameloblastin (AMBN) and enamelin (ENAM), have been extensively studied in mammals. More recently, a fourth protein belonging to the same family has been identified: amelotin (AMTN). AMTN has only been studied in rodents and its role during amelogenesis remains unclear.The aim of this thesis is to extend the knowledge on AMTN by studying its evolution in amniotes and its expression in the lizard Anolis carolinensis.AMTN sequences from many amniote species have been extracted from databases or obtained by PCR, and analyzed. Those analyses allowed us to reveal differences in the gene structure and to highlight residues that were conserved during mammalian or amniote evolution. These conserved amino acids are essential to the structure and/or function of the protein.The expression of AMTN and of AMEL, AMBN and ENAM has been studied by in situ hybridization on lizard jaw sections. Comparison of the expression pattern of these genes during amelogenesis in the lizard with that described in rodents points to similarities (AMEL, AMBN and ENAM) but also to important differences, especially in the spatio-temporal expression of AMTN. In order to better understand AMTN evolution in tetrapods, I studied its expression in an amphibian (Pleurodeles waltl) and a marsupial (Monodelphis domestica).Taken together, these results suggest a link between the evolution of AMTN gene structure (loss of exons and of functional domains in mammals) and its expression (early in non-mammals versus late in mammals) with the emergence of prismatic structure of enamel in early mammals.
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Avalia??o da osseointegra??o de implantes de tit?nio submetidos a diferentes tratamentos de superf?cies

Renz, Renata Pedrolli 14 December 2008 (has links)
Made available in DSpace on 2015-04-14T13:58:27Z (GMT). No. of bitstreams: 1 402797.pdf: 6535759 bytes, checksum: d71c96f436ffa7b29f0ee38a5038a7f7 (MD5) Previous issue date: 2008-12-14 / O processo de osseointegra??o est? fortemente ligado com as propriedades f?sicoqu?micas superficiais dos materiais utilizados em implantes. Pesquisas recentes indicam que o desenvolvimento de superf?cies texturizadas aumenta a efici?ncia deste processo, influenciando diretamente na resposta inicial das c?lulas na interface osso/implante, na taxa e na qualidade da forma??o do tecido ?sseo formado. Por?m, n?o foi verificada a melhor rela??o entre os diversos tipos de tratamentos de superf?cies e a ades?o ?ssea ao implante. O objetivo deste trabalho foi avaliar a osseointegra??o in vivo de implantes de tit?nio cil?ndricos, submetidos a diferentes tratamentos de superf?cie, atrav?s de ensaio mec?nico do tipo pull out, de acordo com a norma ASTM C 633. A morfologia superficial dos implantes foi caracterizada pelas t?cnicas de MEV e rugosimetria. A composi??o qu?mica foi avaliada pelas t?cnicas de EDS e XRF, de acordo com a norma NBR ISO 5832-2, enquanto que, para avaliar a resist?ncia ? corros?o, foi utilizada a t?cnica de Polariza??o Linear, segundo as recomenda??es da ASTM F 746. Os resultados indicaram que a composi??o qu?mica dos grupos de amostras, com exce??o do escovado, atende aos limites estipulados quanto ao teor de contaminantes presentes. Os valores de densidade de corrente indicam comportamento de passiva??o, significativamente abaixo do valor m?ximo permitido pela norma. Os testes de pull out mostraram que 30 dias de cicatriza??o foram insuficientes para se obter crescimento ?sseo satisfat?rio. De modo geral, pode-se dizer que os resultados obtidos para o grupo de 60 dias indicaram que os valores de rugosidade superficial influenciaram os valores de tens?o m?xima.

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