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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.
111

Influ?ncia das caracter?sticas oclusais na ocorr?ncia de traumatismo dent?rio em pr?-escolares: um estudo de caso-controle

Miranda, Ednele Fabyene Primo 15 July 2016 (has links)
?rea de concentra??o: Odontopediatria. / Linha de pesquisa: Epidemiologia e controle das doen?as bucais. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-07-20T20:17:01Z No. of bitstreams: 2 ednele_fabyene_primo_miranda.pdf: 2236077 bytes, checksum: 899a017f3e19d61a71fc17d64a10d45b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-07-28T17:13:01Z (GMT) No. of bitstreams: 2 ednele_fabyene_primo_miranda.pdf: 2236077 bytes, checksum: 899a017f3e19d61a71fc17d64a10d45b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-07-28T17:13:01Z (GMT). No. of bitstreams: 2 ednele_fabyene_primo_miranda.pdf: 2236077 bytes, checksum: 899a017f3e19d61a71fc17d64a10d45b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / Caracter?sticas oclusais est?o associadas ? ocorr?ncia de traumatismo dent?rio em pr?-escolares. Sobressali?ncia acentuada tem sido frequentemente apontada como poss?vel fator de risco para ocorr?ncia de traumatismo dent?rio. No entanto, a mordida aberta anterior, as mordidas cruzadas anterior e posterior e o apinhamento dental t?m sido pouco investigados e apresentam resultados n?o conclusivos na denti??o dec?dua. Assim, o presente estudo buscou investigar a influ?ncia das caracter?sticas oclusais na ocorr?ncia de traumatismo dent?rio em pr?-escolares. Trata-se de um estudo caso-controle de base populacional (1:1), realizado na cidade de Diamantina - Brasil. Ap?s a realiza??o de um estudo transversal as crian?as de 3 a 5 anos de idade com traumatismo dent?rio foram sorteadas para compor o grupo caso (n=200). O grupo controle foi composto por crian?as sem hist?ria de traumatismo dent?rio e pareadas com as crian?as do grupo caso empregando os seguintes crit?rios (1.escola, 2.sexo, 3.idade). As vari?veis independentes foram coletadas por serem de interesse para o estudo (caracter?sticas oclusais) ou por atuarem como potenciais confundidoras (vari?veis sociodemogr?ficas, h?bitos de suc??o e cobertura labial). Os valores de kappa intraexaminador e inter-examinador foram superiores a 0,80 para todas as condi??es bucais avaliadas. Para a an?lise dos dados utilizou-se o programa SPSS 22.0. Foram realizadas as an?lises descritiva, univariada e de regress?o log?stica simples e m?ltipla. Para cada vari?vel de interesse (caracter?stica oclusal), foram criados 5 modelos de ajuste para as vari?veis confundidoras. Na an?lise univariada, observou-se associa??o estatisticamente significativa para as vari?veis, apinhamento anterior superior (p=0,024), mordida aberta (p=<0,001), sobressali?ncia (p=<0,001) e cobertura labial (p=<0,001). Ap?s a regress?o log?stica, a mordida aberta anterior manteve a signific?ncia estat?stica nos cinco modelos de ajuste (OR= 3,80; IC 95%=1,42 ? 10,16). As vari?veis apinhamento anterior superior (OR=2,14; IC 95%=1,00 ? 4,63) e sobressali?ncia (OR= 1,12; IC 95%=0,58 ? 2,17) permaneceram associadas ao grupo caso, independentemente das vari?veis de confundimento (vari?veis sociodemogr?ficas, h?bitos de suc??o e cobertura labial), mas perderam a signific?ncia no modelo 5, quando foram ajustadas por outros tipos de m? oclus?o. Conclui-se que a mordida aberta anterior permaneceu fortemente associada ao traumatismo dent?rio, independentemente das vari?veis de confus?o e de outros tipos de m? oclus?o. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Odontologia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / Occlusal characteristics are associated with the occurrence of dental trauma in preschool children. Accentuated overjet has been frequently pointed as a possible risk factor for dental trauma. However, anterior open bite, anterior and posterior crossbite and dental crowding have been little investigated and show non-conclusive results in the deciduous teeth. Therefore, the present study sought to investigate the influence of occlusal characteristics in the occurrence of dental trauma in preschool children. This is a population based case-control study (1:1), held in the city of Diamantina-Brazil. After conducting a cross-sectional study, children between the ages of 3 to 5 years old with dental trauma were randomly chosen to the case group (n=200). The control group was made of children without dental trauma history and paired with the case group children using the following criteria (1. school, 2. gender, 3. age). The independent variables were collected because of the studies? interest (occlusal characteristics) or because of its potential as a confounding factor (sociodemographic variables, suction habits and lip coverage). The intra and inter-examiner kappa values were greater than 0,80 for all of the oral conditions assessed. The SPSS 22.0 program was used for data analysis. The descriptive, univariate, simple and multiple logistics regression analysis were performed. For each variable of interest (occlusal characteristic), five adjustment models for the confounding variables were created. In the univariate analysis, statistically significant association was observed for the variables: superior anterior crowding (p=0,024), open bite (p=<0,001), overjet (p=<0,001) and lip coverage (p=<0,001). After logistic regression, anterior open bite kept the statistic significance in all five adjustment models (OR= 3,80; IC 95%=1,42 ? 10,16). The anterior superior crowding variable (OR=2,14; IC 95%=1,00 ? 4,63) and the overjet variable (OR= 1,12; IC 95%=0,58 ? 2,17) remained associated with the case group, regardless of the confounding variables (sociodemographic variables, suction habits and lip coverage), but lost significance in model 5, when adjusted for other types of malocclusion. In conclusion, anterior open bite remained strongly associated with dental trauma, regardless of the confounding variables and of other types of malocclusion.
112

Avalia??o de les?es brancas de c?ries: um estudo de progn?stico

Mendes, Neusa Sales 14 March 2011 (has links)
Made available in DSpace on 2014-12-17T15:30:57Z (GMT). No. of bitstreams: 1 NeuzaSM_DISSERT.pdf: 1096884 bytes, checksum: 64158d211b184c940877d132acbd6173 (MD5) Previous issue date: 2011-03-14 / Objective: The aim of the present study is to assess the current situation of white enamel lesions on vestibular surfaces of permanent upper incisors, diagnosed 6 years ago, without clinical intervention. Methods: A prospective study reassessed 53 students of both sexes, aged between 13 and 18 years old, all attending the public school system in Natal, Brazil. Data collection was performed by duly calibrated examiners, and a clinical chart consisting of demographic data on dental caries, oral hygiene, and gingival condition was prepared. A tactile-visual examination was conducted using a clinical mirror and periodontal probe. Data compilation and analysis were carried out using a SPSS software. In this analysis the chi-squared test was used for qualitative independent variables. To identify the net effect of treatment, multiple logistic analysis with forward stepwise model selection was performed. Results: The final sample was composed of 106 lesions in the 53 individuals, with mean age of 15.02 years, visible plaque index (VPI) of 23.34%, and gingival blood indices (GBI) of 25.92%. A statistically significant relationship (p = 0.003) was found between initial DMFS and prognosis of white enamel lesion. Conclusions: We observed that past caries experience and dental plaque were the main predictive factors for negative lesion outcomes, demonstrating the need for oral hygiene control through continuing preventive measures / Objetivo: O presente estudo tem como objetivo avaliar a situa??o atual de les?es brancas de c?rie, bem como a influencia dos fatores preditores no progn?stico dessas les?es, diagnosticadas h? 6 anos, sem interven??o cl?nica. M?todos: Um estudo do tipo prospectivo avaliou 53 estudantes da rede p?blica da cidade de Natal/Brasil, entre 13 e 18 anos, de ambos os sexos. A coleta de dados foi realizada por um examinador devidamente calibrado, com o aux?lio de uma ficha cl?nica composta por dados demogr?ficos, como tamb?m de c?rie dent?ria e higiene oral. O exame executado foi do tipo t?til-visual, com a utiliza??o de espelho cl?nico e sonda periodontal, sendo registrado para a c?rie dent?ria ( CPO-S,Nc?rie e CPOCEO) e para a higiene oral (IPV e ISG). A tabula??o e a an?lise dos dados foram realizadas no software SPSS. Nesta an?lise foi utilizado o teste de associa??o Qui-Quadrado para as vari?veis independentes qualitativas. Para a identifica??o do efeito l?quido, foi realizada a an?lise de regress?o log?stica m?ltipla com uma modelagem do tipo stepwise forward. Resultados: A amostra final foi composta por 106 les?es de 53 indiv?duos, com m?dia de idade 15,02 anos, com ?ndices elevados de placa vis?vel (IPV 23,34%) e de sangramento gengival (ISG 25,92%). Foi verificada uma rela??o estatisticamente significativa (p = 0,003) entre as vari?veis CPO-S2 inicial e o progn?stico das les?es brancas. Conclus?o: Foi observado que uma maior experi?ncia passada de c?rie somada a presen?a de biofilme dent?rio s?o os principais fatores preditores para o desfecho negativo das les?es, demonstrando a necessidade de um controle cont?nuo da higiene oral e da aplica??o constante de medidas preventivas para o sucesso cl?nico, que seria a inativa??o das les?es brancas de c?rie
113

Effet de l’hypoxie sur les cellules souches mésenchymateuses de la pulpe dentaire dans un objectif d’ingénierie tissulaire / Effect of hypoxia on dental pulp mesenchymal stem cells for pulp tissue engineering

Gorin, Caroline 15 June 2015 (has links)
La dent est un tissu vivant, confronté tout au long de la vie à de multiples agressions (caries, traumatismes...) qui peuvent entraîner la nécrose de la pulpe. La mise au point d’une «pulpe équivalente» pourrait constituer une approche thérapeutique innovante comme alternative aux traitements actuels d’endodontie. La pulpe des dents temporaires constitue un réservoir de cellules souches mésenchymateuses (SHED Stem cells from Human Exfoliated Deciduous teeth) aux potentiels de prolifération et de différenciation élevés. L’objectif global de ce travail est de reconstituer un tissu pulpaire fonctionnel en développant une pulpe équivalente (cellules pulpaires mésenchymateuses ensemencées dans une matrice 3D de collagène) pour être greffée à l’intérieur de la chambre pulpaire préalablement évidée afin de conserver la vitalité de la dent. Les objectifs spécifiques ont été : In vitro : 1) d'étudier le potentiel angiogénique des SHED comparés à des fibroblastes dermiques en conditions normoxiques et hypoxiques, 2) de déterminer la durée de pré-conditionnement hypoxique optimale pour stimuler le potentiel angiogénique des SHED, 3) de sélectionner une potentielle cytokine activant la formation de capillaires, 4) d’analyser l’effet de l’hypoxie sur l’expression des marqueurs de surfaces des SHED, et 5) de vérifier que l’hypoxie n’altérait pas le potentiel de minéralisation de ces cellules. In vivo : 1) d’évaluer, dans un modèle pré-clinique d’implantation de pulpes équivalentes en site ectopique chez la souris, l’effet du pré-conditionnement hypoxique sur le potentiel angiogénique des SHED. Ces expériences ont d’abord été conduites avec des cellules pulpaires de souris puis confirmées avec des SHED implantées dans des souris immunodéficientes, et 2) de développer des techniques d’imagerie dynamique pour suivre la néoangiogenèse dans les pulpes équivalentes implantées. Enfin, dans un objectif de transfert vers la clinique dentaire humaine, nous avons étudié l’effet d’un nouveau biomatériau à base de calcium tricalcique sur la réparation tissulaire dans un modèle de blessure pulpaire chez le rat, en comparaison aux matériaux de référence. / The tooth is a living organ, faced throughout life to multiple attacks (caries, trauma ...) which can cause necrosis of the pulp. The development of a" pulp equivalent " could be an innovative therapeutic approach as an alternative to current endodontic treatments. The pulp of deciduous teeth is a reservoir of mesenchymal stem cells (Stem cells SHED from Human Exfoliated Deciduous teeth) with a high potential of proliferation and differentiation. The overall objective of this work was to reconstitute a functional pulp tissue by developing a pulp equivalent (pulp mesenchymal cells seeded in a 3D collagen matrix) to be grafted within the previously hollowed pulp chamber to maintain tooth vitality. The specific objectives were: In vitro: 1) to study the angiogenic potential of SHED compared with dermal fibroblasts in normoxic and hypoxic conditions. 2) to determine the optimal hypoxic preconditioning period to stimulate the angiogenic potential of SHED, 3) to identify a potential cytokine activating the capillary formation, 4) to analyze the effect of hypoxia on the expression of markers surfaces SHED, and 5) to check that hypoxia did not alter the mineralization potential of these cells. In vivo: 1) to evaluate, in a pre-clinical model of pulp equivalent implantation in ectopic site in mice, the effect of either hypoxic or FGF preconditioning on the angiogenic potential of SHED. These experiments were first conducted with mouse pulp cells and further confirmed with SHED implanted in immunodeficient mice, and 2) to develop dynamic imaging techniques to monitor neoangiogenesis within pulp equivalent. Finally, in an objective of transfer to the human dental clinic, we studied the effect of a new biomaterial based on tricalcium on tissue repair in a pulp injury model in rats, compared to gold standard materials.
114

Effet de l’hypoxie sur les cellules souches mésenchymateuses de la pulpe dentaire dans un objectif d’ingénierie tissulaire / Effect of hypoxia on dental pulp mesenchymal stem cells for pulp tissue engineering

Gorin, Caroline 15 June 2015 (has links)
La dent est un tissu vivant, confronté tout au long de la vie à de multiples agressions (caries, traumatismes...) qui peuvent entraîner la nécrose de la pulpe. La mise au point d’une «pulpe équivalente» pourrait constituer une approche thérapeutique innovante comme alternative aux traitements actuels d’endodontie. La pulpe des dents temporaires constitue un réservoir de cellules souches mésenchymateuses (SHED Stem cells from Human Exfoliated Deciduous teeth) aux potentiels de prolifération et de différenciation élevés. L’objectif global de ce travail est de reconstituer un tissu pulpaire fonctionnel en développant une pulpe équivalente (cellules pulpaires mésenchymateuses ensemencées dans une matrice 3D de collagène) pour être greffée à l’intérieur de la chambre pulpaire préalablement évidée afin de conserver la vitalité de la dent. Les objectifs spécifiques ont été : In vitro : 1) d'étudier le potentiel angiogénique des SHED comparés à des fibroblastes dermiques en conditions normoxiques et hypoxiques, 2) de déterminer la durée de pré-conditionnement hypoxique optimale pour stimuler le potentiel angiogénique des SHED, 3) de sélectionner une potentielle cytokine activant la formation de capillaires, 4) d’analyser l’effet de l’hypoxie sur l’expression des marqueurs de surfaces des SHED, et 5) de vérifier que l’hypoxie n’altérait pas le potentiel de minéralisation de ces cellules. In vivo : 1) d’évaluer, dans un modèle pré-clinique d’implantation de pulpes équivalentes en site ectopique chez la souris, l’effet du pré-conditionnement hypoxique sur le potentiel angiogénique des SHED. Ces expériences ont d’abord été conduites avec des cellules pulpaires de souris puis confirmées avec des SHED implantées dans des souris immunodéficientes, et 2) de développer des techniques d’imagerie dynamique pour suivre la néoangiogenèse dans les pulpes équivalentes implantées. Enfin, dans un objectif de transfert vers la clinique dentaire humaine, nous avons étudié l’effet d’un nouveau biomatériau à base de calcium tricalcique sur la réparation tissulaire dans un modèle de blessure pulpaire chez le rat, en comparaison aux matériaux de référence. / The tooth is a living organ, faced throughout life to multiple attacks (caries, trauma ...) which can cause necrosis of the pulp. The development of a" pulp equivalent " could be an innovative therapeutic approach as an alternative to current endodontic treatments. The pulp of deciduous teeth is a reservoir of mesenchymal stem cells (Stem cells SHED from Human Exfoliated Deciduous teeth) with a high potential of proliferation and differentiation. The overall objective of this work was to reconstitute a functional pulp tissue by developing a pulp equivalent (pulp mesenchymal cells seeded in a 3D collagen matrix) to be grafted within the previously hollowed pulp chamber to maintain tooth vitality. The specific objectives were: In vitro: 1) to study the angiogenic potential of SHED compared with dermal fibroblasts in normoxic and hypoxic conditions. 2) to determine the optimal hypoxic preconditioning period to stimulate the angiogenic potential of SHED, 3) to identify a potential cytokine activating the capillary formation, 4) to analyze the effect of hypoxia on the expression of markers surfaces SHED, and 5) to check that hypoxia did not alter the mineralization potential of these cells. In vivo: 1) to evaluate, in a pre-clinical model of pulp equivalent implantation in ectopic site in mice, the effect of either hypoxic or FGF preconditioning on the angiogenic potential of SHED. These experiments were first conducted with mouse pulp cells and further confirmed with SHED implanted in immunodeficient mice, and 2) to develop dynamic imaging techniques to monitor neoangiogenesis within pulp equivalent. Finally, in an objective of transfer to the human dental clinic, we studied the effect of a new biomaterial based on tricalcium on tissue repair in a pulp injury model in rats, compared to gold standard materials.
115

The Incorporation of Vinyl Modified Regenerated Starch Nanoparticles in Emulsion Polymerizations

Cummings, Shidan January 2017 (has links)
The replacement of synthetic polymers with renewable content in emulsion polymerization latexes has been a focus of research over the past several decades. Emulsion polymerization is a more sustainable way to produce polymers for films and resins. Starch is a sustainably sourced material that has proven to be extremely useful as a filler, comonomer, and property modifier for polymer latexes. In this thesis, we attempt to incorporate high levels of starch materials into emulsion latex using waxy and dent sourced (cheaper) vinyl-functionalized regenerated starch nanoparticles (RSNPs). When fed as a batch charge, incorporation (by reaction as opposed to blending) of a grade of waxy RSNPs with 3 wt.% polymerizable sugar-based monomer (PSBM) and medium hydrophobicity (S-3-M) into the polymer matrix was 0-10 wt.% for a 15 wt.% RSNP loaded, 40 wt.% solids latex. Semi-batch feeding of the S-3-M RSNPs resulted in stable latex with the highest loadings of 40 and 50 wt.% (40 wt.% solids) with 0-10 wt.% RSNP incorporation into the synthetic particles, while 40 wt.% loading (20 wt.% incorporation) was achieved with a grade of waxy RSNPs with 6 wt.% PSBM and medium hydrophobicity (S-6-M). Strategies were developed to prepare synthetic latexes with high RSNP loadings and moderate incorporation. Dent sourced RSNPs proved difficult to use in emulsion formulations due in part to the higher percentage of water-soluble linear amylose in the nanoparticles. To reduce the chances of coagulation and minimize the viscosity of the final latex it was important to ensure monomer starved conditions, that the only initiator feed occurred at the seed stage of the reaction (to degrade the soluble starch and prevent later stage coagulation), and that a hydrophobic tie-layer was used to assist in removal of soluble starch from the water phase. Although a successful procedure was devised for creating a dent sourced RSNP loaded latex with a viscosity of 250 cp, it was significantly longer than the procedures used with waxy RSNPs (6 h polymerization + 1 h RSNP dispersion). An additional treatment of the RSNP dispersion prior to the polymerization can lower the final latex viscosity to 100 cp. Higher incorporation of vinyl-functionalized RSNPs may be achievable if the covalently bonded PSBM functional groups are resistant to hydrolysis, the amylose and other small MW starches are completely removed from the water phase, and monomers with more appropriate reactivity and hydrophobicity are employed. To this end, maleic and methacrylic anhydride modified RSNPs were prepared and tested in emulsion polymerizations. The maleic anhydride modified RSNPs were successfully loaded into an emulsion latex at 15 wt.% (40 wt.% solids content) resulting in 20-30 wt.% incorporation when utilizing 2-ethylhexyl acrylate as the tie-layer monomer with 2-ethylhexyl acrylate or butyl acrylate/methyl methacrylate/acrylic acid as the shell layer. This work presents the only comprehensive attempt to incorporate RSNPs into synthetic latexes at high loadings and solids with persulfate initiation without the need to severely reduce the RSNP molecular weight. The learning generated provides a framework for continuing research into increasing the incorporation of RSNPs into polymer particles.
116

Effet de l’hypoxie sur les cellules souches mésenchymateuses de la pulpe dentaire dans un objectif d’ingénierie tissulaire / Effect of hypoxia on dental pulp mesenchymal stem cells for pulp tissue engineering

Gorin, Caroline 15 June 2015 (has links)
La dent est un tissu vivant, confronté tout au long de la vie à de multiples agressions (caries, traumatismes...) qui peuvent entraîner la nécrose de la pulpe. La mise au point d’une «pulpe équivalente» pourrait constituer une approche thérapeutique innovante comme alternative aux traitements actuels d’endodontie. La pulpe des dents temporaires constitue un réservoir de cellules souches mésenchymateuses (SHED Stem cells from Human Exfoliated Deciduous teeth) aux potentiels de prolifération et de différenciation élevés. L’objectif global de ce travail est de reconstituer un tissu pulpaire fonctionnel en développant une pulpe équivalente (cellules pulpaires mésenchymateuses ensemencées dans une matrice 3D de collagène) pour être greffée à l’intérieur de la chambre pulpaire préalablement évidée afin de conserver la vitalité de la dent. Les objectifs spécifiques ont été : In vitro : 1) d'étudier le potentiel angiogénique des SHED comparés à des fibroblastes dermiques en conditions normoxiques et hypoxiques, 2) de déterminer la durée de pré-conditionnement hypoxique optimale pour stimuler le potentiel angiogénique des SHED, 3) de sélectionner une potentielle cytokine activant la formation de capillaires, 4) d’analyser l’effet de l’hypoxie sur l’expression des marqueurs de surfaces des SHED, et 5) de vérifier que l’hypoxie n’altérait pas le potentiel de minéralisation de ces cellules. In vivo : 1) d’évaluer, dans un modèle pré-clinique d’implantation de pulpes équivalentes en site ectopique chez la souris, l’effet du pré-conditionnement hypoxique sur le potentiel angiogénique des SHED. Ces expériences ont d’abord été conduites avec des cellules pulpaires de souris puis confirmées avec des SHED implantées dans des souris immunodéficientes, et 2) de développer des techniques d’imagerie dynamique pour suivre la néoangiogenèse dans les pulpes équivalentes implantées. Enfin, dans un objectif de transfert vers la clinique dentaire humaine, nous avons étudié l’effet d’un nouveau biomatériau à base de calcium tricalcique sur la réparation tissulaire dans un modèle de blessure pulpaire chez le rat, en comparaison aux matériaux de référence. / The tooth is a living organ, faced throughout life to multiple attacks (caries, trauma ...) which can cause necrosis of the pulp. The development of a" pulp equivalent " could be an innovative therapeutic approach as an alternative to current endodontic treatments. The pulp of deciduous teeth is a reservoir of mesenchymal stem cells (Stem cells SHED from Human Exfoliated Deciduous teeth) with a high potential of proliferation and differentiation. The overall objective of this work was to reconstitute a functional pulp tissue by developing a pulp equivalent (pulp mesenchymal cells seeded in a 3D collagen matrix) to be grafted within the previously hollowed pulp chamber to maintain tooth vitality. The specific objectives were: In vitro: 1) to study the angiogenic potential of SHED compared with dermal fibroblasts in normoxic and hypoxic conditions. 2) to determine the optimal hypoxic preconditioning period to stimulate the angiogenic potential of SHED, 3) to identify a potential cytokine activating the capillary formation, 4) to analyze the effect of hypoxia on the expression of markers surfaces SHED, and 5) to check that hypoxia did not alter the mineralization potential of these cells. In vivo: 1) to evaluate, in a pre-clinical model of pulp equivalent implantation in ectopic site in mice, the effect of either hypoxic or FGF preconditioning on the angiogenic potential of SHED. These experiments were first conducted with mouse pulp cells and further confirmed with SHED implanted in immunodeficient mice, and 2) to develop dynamic imaging techniques to monitor neoangiogenesis within pulp equivalent. Finally, in an objective of transfer to the human dental clinic, we studied the effect of a new biomaterial based on tricalcium on tissue repair in a pulp injury model in rats, compared to gold standard materials.
117

Sources alternatives de cellules souches pour la bio-ingénierie de la dent / Alternative sources of stem cells for tooth bioengineering

Acuña Mendoza, Soledad 29 October 2015 (has links)
Les cellules de la crête neurale (CN) sont une population de cellules multipotentes que pendant le développement embryonnaire vont migrer et se différencier vers divers lignages comme mélanocytes, muscle lisse, neurones périphériques et entériques, glie ainsi que tissus mésenchymateux cranio-faciaux y compris ceux de la dent. Dans le contexte de l’étude de modèles pour l’ingénierie tissulaire de la dent, nous avons établi une nouvelle lignée de cellules souches embryonnaires (ES) à partir de blastocystes issus de croisements entre un souris Wnt1-Cre et souris rapportrices fluorescentes, les Rosa26 mT/mT. Dans ce system, les cellules qui acquièrent l’identité CN et expriment le gène Wnt1 vont devenir fluorescentes grâce à l’activation de la protéine Tomato, ce qui permet de suivre 1) leur différenciation in vitro 2) isolement et 3) devenir lorsqu’elles sont utilisées dans de modèles in vivo. En parallèle, nous avons mis au point un nouveau protocole simplifié de différenciation (monocouche et milieu défini), vers un phénotype CN. Finalement nous avons tenté de développer un protocole d’induction d’une compétence odontogénique. Notre étude montre que la lignée Wnt1 Cre/Tomato 1) présentent toutes les caractéristiques d’une lignée ES classique i.e. expression de marqueurs de pluripotence, caryotype normal, capacité à se différencier in vitro et in vivo en tissus dérivés des 3 feuillets embryonnaires 2) acquièrent une identité CN, après induction in vitro avec notre protocole de différenciation. 3) Par l’intermédiaire de réassociations tissulaires in vitro, nous avons montré que ces cellules sont capables d’interagir avec un épithélium oral pour former des tissus squelettiques oro-faciaux. Ce nouvel outil cellulaire devrait aider à la compréhension des signaux impliqués dans le dialogue ectomésenchymateux qui sous-tend la formation des tissus durs de la face mais aussi plus généralement permettre suivir le devenir de cellules CN dans des modèles d’ingénierie tissulaire. / Neural crest cells are multipotent progenitor cells that, during embryogenic development, migrate and differentiate into diverse lineages such as melanocytes, smooth muscle, peripheral and enteric neurons, glial cells as well as craniofacial mesenchymatic components, including teeth. In the context of the development of an odontogenic model for tissue engineering, we have generated a new cell line of embryonic stem cells (ES) obtained from blastocysts from crossing Wnt1-CRE mice with fluorescent reporter Rosa26 mT/mT mice. In this Cre/Lox system the cells that have acquired a CN identity and thus expressing Wnt1, will become and remain fluorescent due to the activation of Tomato expression. We have generated a simplified protocol in a monolayer cell culture in defined serum-free medium in order to differentiate the cells into CN cells, named ES-CN cells. Second, we investigated the signals necessary for the odontogenic specification of these ES-CN cells. Our study provides evidence that the Wnt1-CRE/Tomato cell line 1) is a competent ES cell line with the expression of pluripotent markers, a stable karyotype and the ability to differentiate in vitro and in vivo into all the three embryonic germ layers, 2) acquires in vitro a CN identity after induction with our protocol, 3) expresses odontogenic markers in hypoxic culture conditions and 4) is able to interact with an oral epithelium in order to form orofacial skeletal tissues via the tissue reassociation in vitro. This novel cell model should facilitate the understanding of the mechanisms implicated in the ectomesenchymatic interaction, at the base for formation of orofacial skeletal tissues, and will provide the possibility to follow the fate of ES-CN cells tissue engineering models of wounded orofacial structures in general.
118

Efeitos do envelhecimento na altura ?ssea periimplantar

Pedro, Rejane Eliete Luz 28 May 2013 (has links)
Made available in DSpace on 2015-04-14T13:54:03Z (GMT). No. of bitstreams: 1 451173.pdf: 1812168 bytes, checksum: 8a896e7fcd7b000f80719ab791ec8cbc (MD5) Previous issue date: 2013-05-28 / Tooth loss is very common in the older people causing a need for a rehabilitative treatment by dental implants. The periimplant bone loss is one of the most important factors for the success of dental implants activated. Ageing, however, is associated with decreased bone metabolism; making can be a risk factor for the loss of these implants. It is known that bone loss can also be influenced by other factors such as gender, bruxism, diabetes, osteoporosis, heart disease, hypothyroidism, alcohol and smoking. This study aimed to monitor radiographic and clinically, for four years, the periimplant bone level from the installation of prostheses placed in dental implants. Were followed 18 patients, 57 patients with dental implants with their respective prosthesis installed, observing the periimplant bone height and systemic diseases present. The loss of periimplant bone height was significantly associated with a history of smoking and to be man, age was inversely associated with bone loss. Factors such as the presence of hypothyroidism, diabetes, hypertension, heart disease and osteoporosis were not associated with bone loss. There were no significant differences in nutritional parameters of patients followed. We conclude that age was a factor associated with height gain and bone that elderly male with a previous history of smoking are associated with loss of periimplant bone height. / A perda dent?ria ? muito comum no idoso fazendo com que exista a necessidade de um tratamento reabilitador por meio de implantes osseointegrados. A perda ?ssea periimplantar ? um dos fatores mais importantes para o sucesso dos implantes osseointegrados ativados. O envelhecimento, entretanto, est? associado ? diminui??o do metabolismo ?sseo, fazendo com que possa ser um fator de risco para a perda desses implantes. Sabe-se que a perda ?ssea pode tamb?m ser influenciada por outros fatores como sexo, bruxismo, diabetes, osteoporose, cardiopatias, hipotireoidismo, ?lcool e tabagismo. O presente trabalho teve como objetivo principal acompanhar radiogr?fica e clinicamente, durante quatro anos, o n?vel ?sseo periimplantar a partir da instala??o de pr?teses colocadas nos implantes osseointegrados. Foram acompanhados 18 pacientes, portadores de 57 implantes osseointegrados com suas respectivas pr?teses instalados, observando-se a altura ?ssea periimplantar e as doen?as sist?micas presentes. A perda da altura ?ssea periimplantar foi significativamente associada com hist?ria pr?via de tabagismo e sexo masculino, idade foi inversamente associada ? perda de massa ?ssea. Fatores como presen?a de hipotireoidismo, diabetes, hipertens?o, cardiopatia e osteoporose n?o foram associados ? perda ?ssea. N?o foram observadas diferen?as significativas nos par?metros nutricionais dos pacientes acompanhados. Conclui-se que idade foi um fator associado ao ganho de altura ?ssea e que idosos do sexo masculino e com hist?ria pr?via de tabagismo est?o associados ? perda de altura ?ssea periimplantar.
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Tradu??o e valida??o de um question?rio sobre aspectos emocionais e sociais relacionados ? alimenta??o de usu?rios de pr?teses dent?rias

Valdez, Eduardo Jos? 02 March 2015 (has links)
Made available in DSpace on 2015-04-14T13:54:17Z (GMT). No. of bitstreams: 1 466320.pdf: 1945321 bytes, checksum: a912d2ef37daa2e76c0ca2c193b5362e (MD5) Previous issue date: 2015-03-02 / Introduction: To assess the impact of prosthetic rehabilitation and formulate a suitable dietary advice is necessary to obtain detailed information about the experience of eating in patients who use dentures. The objective of this study was to translate to Brazilian Portuguese, culturally adapt and validate a questionnaire that reflects the concerns of denture wearers on aspects of their wellbeing related to food. Methods: The instrument was translated, back-translated, evaluated by a committee of experts, and then went through a process of cultural adaptation, following the World Health Organization standards for test translation. To test the Reliability of the instrument Cronbach's alpha coefficient was applied to assess the internal consistency. The Intraclass correlation test (ICC) and the difference between the means of the VAS scores for each domain were applied to evaluate the concordance of responses in two different moments. Results: The instrument was applied to 24 dental wearers, twice with 2 to 15 days of interval. The internal consistency was considered acceptable (0.77) only in the domain 'enjoyment of food/eating' and good for the other domains, ranging between 77 and 95%. The instrument showed good reproducibility, with ICC values between 0.77 and 0.95. Conclusion: A Brazilian Portuguese version of the ESIRE questionnaire was adapted culturally. Internal consistency and reliability of the data allow the instrument to be used to obtain additional information related to the denture users experiences with eating in further research or in dental offices. / Introdu??o: Para avaliar o impacto da reabilita??o prot?tica e formular um aconselhamento diet?tico adequado ? necess?rio obter informa??es detalhadas sobre as experi?ncias relacionadas ? alimenta??o de pacientes que usam pr?teses dent?rias. O objetivo deste estudo foi traduzir para o portugu?s brasileiro, adaptar culturalmente e validar um question?rio que reflete as preocupa??es dos usu?rios de pr?teses dent?rias relacionadas ao bem estar com a alimenta??o. M?todos: o instrumento foi traduzido, retrotraduzido e avaliado por um comit? de especialistas. Posteriormente passou por processo de adapta??o cultural, conforme o protocolo de tradu??o de instrumentos da Organiza??o Mundial de Sa?de, e validado. Para testar a confiabilidade, o coeficiente Alpha de Cronbach foi aplicado, avaliando a consist?ncia interna do instrumento. O Coeficiente da Correla??o Intraclasse (CCI) e a diferen?a entre escores nos diferentes dom?nios foram aplicados para avaliar a reprodutibilidade do question?rio em dois momentos distintos. Resultados: O instrumento foi aplicado em 24 indiv?duos portadores de pr?tese dent?ria em dois momentos com intervalo de 2 a 15 dias. A consist?ncia interna foi considerada aceit?vel (0,77) somente no dom?nio satisfa??o com a alimenta??o e boa para os demais dom?nios, variando entre 77 e 95%. O instrumento mostrou-se de boa reprodutibilidade, com valores do CCI, entre 0,77 e 0,95. Conclus?o: Uma vers?o em portugu?s do question?rio ESIRE foi adaptada. Os dados de consist?ncia interna, reprodutibilidade e valida??o permitem que o instrumento seja utilizado para obten??o de informa??es adicionais relacionadas a alimenta??o de usu?rios de pr?teses dent?rias em novas pesquisas ou em consult?rios odontol?gicos.
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Altera??es centrais e perif?ricas em diferentes modelos de dor pulpar em ratos

Filippini, Helena Fetter 13 January 2017 (has links)
Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-03-23T15:01:59Z No. of bitstreams: 1 TES_HELENA_FETTER_FILIPPINI_PARCIAL.pdf: 1312432 bytes, checksum: dda78ca2fa347004234d72add7b38398 (MD5) / Made available in DSpace on 2017-03-23T15:01:59Z (GMT). No. of bitstreams: 1 TES_HELENA_FETTER_FILIPPINI_PARCIAL.pdf: 1312432 bytes, checksum: dda78ca2fa347004234d72add7b38398 (MD5) Previous issue date: 2017-01-13 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq / The central and peripheral mechanisms involved in pulpal pain are still unclear. This study compared, initially, the chronic pulpitis model evoked by the application of complete Freund's adjuvant (CFA) into the pulps of rats, with other models of pulpitis. For this purpose, the pulps of the left upper first molars of Wistar rats were accessed. There were four experimental groups according to the surgical procedure: open, closed, CFA and na?ve. Behavioral changes, as well as, body weight gain and food and water consumption, were evaluated at different experimental times (1, 2, 3 and 8 days). After euthanasia, blood, brain and trigeminal ganglion (TG) samples were collected for further analysis. All experimental groups with pulp acess had a decrease in body weight gain (for up to 3 days). A reduction in food consumption was observed in all the groups with pulp exposure, on the first day. The CFA group showed a significant reduction of locomotor activity (at 1 and 3 days), which was associated with increased satellite glial cells activation in the ipsilateral TG. Activation of astrocytes in the amygdala was not affected in the studied groups. The second part of this study investigated the relevance of Toll-like receptor 4 (TLR4) activation in the acute pulpitis caused by the application of the transient receptor potential ankyrin-1 (TRPA1) mustard oil (MO), into the rat pulps. Preliminary studies were performed to compare the sensorimotor activity of the masticatory muscles with the application of lipopolysaccharide (LPS) or MO in the dental pulp. The model using MO application into the pulp of rats was selected, because of the marked increase of the electromyographic activities evoked by this agent, when compared to LPS. The animals received a intrathecal (i.t.) pre-treatment with the TLR4 LPS-RS antagonist (25 ?g / 10 ?l) or saline solution (10 ?l) (vehicle group), 10 min before pulp application of MO. For this purpose, a stereotaxic surgery was performed to access the trigeminal subnucleus caudalis. Changes in electromyography activity (EMG) of masticatory muscles were recorded for 15 min after the MO application into the pulp. The trigeminal caudalis subnucleus was removed after euthanasia, for evaluation of TLR4 expression by western blotting analysis. Changes in EMG activity in anterior digastric muscles were significantly reduced by the intrathecal administration of LPS-RS in the trigeminal subnucleus caudalis (p ?0.05). The data obtained suggest the participation of satellite glial cells in the chronic pulpitis model induced by CFA, as well as, TLR4 receptors in the acute pulpitis model caused by MO application into the rat pulps. Altogether, the present results shed new light on the mechanisms underlying acute and chronic tooth pulp inflammatory pain. / Os mecanismos centrais e perif?ricos envolvidos na dor pulpar ainda n?o est?o totalmente claros. O presente estudo comparou, inicialmente, o modelo de inflama??o pulpar cr?nica induzido pela aplica??o de adjuvante completo de Freund (CFA), em polpas de ratos, com outros modelos de pulpite. Para tanto, as polpas dos primeiros molares superiores esquerdos de ratos Wistar foram acessadas. Foram criados 4 grupos experimentais conforme a abordagem pulpar: aberto, fechado, CFA e na?ve. As altera??es comportamentais, bem como, o ganho de peso corporal e o consumo de ?gua e ra??o, foram avaliados em diferentes tempos experimentais (1, 2, 3 e 8 dias). Ap?s a eutan?sia, amostras de sangue, c?rebro e g?nglio trigeminal (GT) foram coletadas para an?lises posteriores. Todos os grupos experimentais com exposi??o da polpa apresentaram diminui??o do ganho de peso corporal (at? o 3 ? dia). A redu??o do consumo de ra??o foi observada em todos os grupos no primeiro dia. O grupo CFA mostrou redu??o significativa na atividade locomotora (em 1 e 3 dias), que foi associada ao aumento da ativa??o das c?lulas sat?lites da glia no GT ipsilateral. A ativa??o de astr?citos na am?gdala n?o foi afetada nos grupos estudados. A segunda parte deste estudo investigou a participa??o do receptor Toll-like 4 (TLR4), na media??o da pulpite aguda causada pela aplica??o de ?leo de mostarda (OM), um agonista de receptores de potencial transit?rio anquirina-1 (TRPA1), em polpas de ratos. Estudos preliminares foram realizados comparando a atividade sensoriomotora dos m?sculos mastigat?rios diante da aplica??o de lipopolissacar?deo (LPS) ou OM na polpa dent?ria. O modelo utilizando OM na polpa de ratos foi escolhido, devido ao aumento marcante das atividades eletromiogr?ficas (EMG), quando comparado ao LPS. Os animais foram pr?-tratados por via intratecal (i.t.) com o antagonista seletivo dos receptores TLR4, o LPS-RS (25 ?g/10 ?l, 10 min antes da aplica??o pulpar de OM. O grupo controle recebeu solu??o salina (10 ?l) (grupo ve?culo), pela mesma via, no mesmo tempo de administra??o. Para tal, foi realizada uma cirurgia esterot?xica para permitir o acesso ao subn?cleo caudal trigeminal. As altera??es das atividades de EMG dos m?sculos mastigat?rios foram registradas durante 15 min ap?s a aplica??o de OM na polpa. O subn?cleo caudal trigeminal foi removido ap?s a eutan?sia, para avalia??o da express?o de TLR4, atrav?s da an?lise de western-blotting. As altera??es da atividade de EMG nos m?sculos dig?stricos anteriores foram significativamente reduzidas pela administra??o intratecal de LPS-RS no subn?cleo caudal do trig?meo (p?0,05), indicando um papel relevante para esses receptores nos mecanismos de sensibiliza??o central, ap?s a aplica??o de OM. O conjunto de dados obtidos sugerem a participa??o das c?lulas sat?lites da glia no modelo de pulpite cr?nica induzida por CFA, bem como, dos receptores TLR4 no modelo de pulpite aguda provocada pela aplica??o de OM em polpas de ratos. Essas evid?ncias contribuem para o melhor entendimento dos mecanismos relacionados com a transmiss?o da dor pulpar aguda e cr?nica.

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