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Thesis (M.S.)--University of Michigan, 1982.

Thesis (M.S.)--University of Michigan, 1982.

Thesis (M.S.)--University of Michigan, 1979.

Made available in DSpace on 2014-06-11T19:33:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-10-10Bitstream added on 2014-06-13T20:24:31Z : No. of bitstreams: 1 pretel_h_dr_arafo.pdf: 3205750 bytes, checksum: ce5e74583f1240f03a35e00b3edb32bb (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O estudo investigou os efeitos da radiação eletromagnética não ionizante emitidos pelos diodos LASER com comprimento de onda no espectro 688 ηm e 785 ηm, e diodo LED 635 ± 10 ηm, associados ao capeamento direto com hidróxido de cálcio em exposições pulpares mecânicas. Avaliou-se assim em dentes de macacos-prego a resposta pulpar baseado na morfologia das células pulpares, no processo inflamatório local, na formação da barreira mineralizada, e na organização do tecido pulpar nos diferentes grupos estudados. Discutiu-se também as diferentes fontes de emissão de radiação eletromagnética comparando os resultados obtidos de estimulação pulpar com os diodos LASER e LED, os quais apresentam energia coerente e não-coerente, respectivamente. Os resultado mostraram uma estimulação em todos os grupos irradiados com melhores resultados para o estímulo com LASER, quando comparado ao grupo tratado isoladamente com hidróxido de cálcio. Concluímos assim que a estimulação de energia eletromagnética LASER e LED associado ao capeamento pulpar direto com hidróxido de cálcio apresentou aceleração no processo de reparação tecidual. Porém, há necessidade de novos estudos com diferentes parâmetros de irradiação a fim de se obter protocolos cada vez mais eficientes para o estudo dos efeitos da luz sobre o processo de reparação pulpar. / The aim of this study was to compare the effects of non-ionizing electromagnetic radiation emitted by LASER diodes 688 ηm and 785 ηm, and LED diode 635 ± 10 ηm associated to direct pulp capping with calcium hydroxide in traumatic pulp exposures were investigated. Based on pulp cells morphology, on the local inflammatory process, on mineralized barrier formation and on pulp tissue organization, the pulp response in capuchin monkey teeth was evaluated in different groups. It was also discussed the different electromagnetic radiation emission sources effects comparing the obtained results of pulp stimulation with diodes LASER and LED, which present coherent and non-coherent energy respectively. Stimulation was observed in all irradiated groups, being the best results achieved with LASER stimulation, when compared to the group treated only with calcium hydroxide. Thus, it is concluded that the electromagnetic LASER and LED energy stimulation associated with calcium hydroxide direct pulp capping accelerated the tissue repair process. However, further studies with different stimulation parameters in order to obtain increasingly efficient protocols to study light effects on pulp repair are necessary.

Made available in DSpace on 2014-06-11T19:24:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-03-12Bitstream added on 2014-06-13T19:52:11Z : No. of bitstreams: 1 crisci_fs_me_arafo.pdf: 2027540 bytes, checksum: 4b3628dd1cdd46049844ef97ba6d858a (MD5) / O presente estudo avaliou a reação histológica do efeito do laser de baixa intensidade diodo semicondutor de arseneto de gálio e alumínio (GaA1As, com comprimento de onda de 785 nm, infravermelho, com potência de emissão de 50 mW, densidade de energia de 3 J/cm2, em emissão contínua, por meio de ponta especial de fibra óptica, por um período de 2 segundos) em exposições pulpares induzidas em dentes de ratos. Foram utilizados 60 ratos, dos quais cada animal ofereceu dois dentes (totalizando 120), que foram distribuídos em 5 grupos experimentais: grupo I (controle), exposição capeada com hidróxido de cálcio; grupo II, laser imediato + hidróxido de cálcio; grupo III, laser imediato + hidróxido de cálcio + laser após 24 horas; grupo IV, laser imediato + hidróxido de cálcio + laser após 24 e 48 horas; e grupo V, somente a aplicação do laser. Decorridos os períodos experimentais de sete e 30 dias, os animais foram mortos, as peças removidas e preparadas para análise histológica. De acordo com a proposta e as condições específicas deste trabalho, os resultados nos permitem concluir que as associações laser imediato + hidróxido de cálcio e laser imediato + hidróxido de cálcio + laser 24 horas, foram os grupos que apresentaram os melhores resultados tanto aos sete dias (efeito antiinflamatório), quanto aos trinta dias (efeito no reparo tecidual). / The present study evaluated the histological reaction of the low poweer laser effect, diode laser semiconductor of gallium aluminum arsenide (GaA1As, with wavelenght of 785 nm, infra-red, potency of emission of 50 mW, energy density of 3 J/cm2, with continuous emission, through special tip of optic fiber, for a period of two seconds) in exposed pulp induced in teeth of mice. Sixty mice were used, of which each animal offered two teeth (totaling 120), that were distributed in 5 experimental groups: group I(control group) exposed capping with calcium hydroxide; group II, immediate laser + calcium hydroxide; group III, immediate laser + calcium hydroxide + laser after 24 hours; group IV, immediate laser + calcium hydroxide + laser after 24 and 48 hours; and group V, only laser application. After the experimental periods of seven and thirty days, the animals were killed, the pieces were removed and prepared for histological analysis. In agreement with the proposal and the specific conditions of this study, the results allow us conclude that the associations of immediate laser + calcium hydroxide and immediate laser + calcium hydroxide + laser after 24 hours, were the groups that presented the best results in the periods of seven days (anti-inflammatory effect), and thirty days (effect in the tissue repair).

O objetivo do presente estudo foi avaliar por meio de observações clínicas e radiográficas a resposta in vivo do complexo dentino-pulpar de dentes decíduos humanos após a realização da remoção parcial e total do tecido cariado. Quarenta e nove molares decíduos de crianças com idades entre 5 a 9 anos foram criteriosamente selecionados. Os dentes foram divididos em dois grupos: Grupo I remoção parcial do tecido cariado; Grupo II remoção total do tecido cariado. As avaliações clínicas e radiográficas foram realizadas nos períodos de 4 a 6 meses do pós-operatório. A reprodutibilidade intra-examinador foi determinada pelo teste Kappa. O teste exato de Fisher foi utilizado para determinar a diferença estatística entre os grupos. Todos os dentes apresentaram sucesso clínico no período de avaliação de 4 a 6 meses. A avaliação radiográfica mostrou 94,2% e 89,6% de sucesso no Grupo I e no Grupo II, respectivamente. Os resultados radiográficos não mostraram diferença estatisticamente significativa nos grupos estudados em nenhum dos critérios avaliados (p>0,05). Com base nos resultados obtidos para amostra estudada, e de acordo com a metodologia aplicada, a remoção parcial do tecido cariado exibiu resultados clínicos e radiográficos satisfatórios, sugerindo que a abordagem minimamente invasiva para remoção de cárie dentária pode substituir a remoção total do tecido cariado quando indicada corretamente. / The aim of this study was to evaluate through clinical and radiographic observation the in vivo response of the dentin pulp complex of human deciduous teeth after the partial and total removal of the caries. Forty-nine deciduous molars in children with the age between 5 and 9 years old were carefully selected. The teeth were divided in two groups: Group I partial removal of caries; Group II total removal of caries. Clinical and radiographic evaluations were performed during the period of 4 to 6 months after procedure. The intra-examiner reproducibility was determined by the Kappa test. The exact fisher test was used to determine the statistical difference between the groups. All teeth showed clinical success in the evaluation period of 4 to 6 months. The radiographic evaluation showed 94,2% and 89,6% of success rate in Group I and in Group II, respectively. Radiographic results did not show statistically significant differences between the studied groups (p>0,05). Based on the obtained results to this sample, and according to the applied methodology, the partial removal of the caries showed satisfactory clinical and radiographic results, suggesting that the minimally invasive approach to the removal of dental caries might substitute the total removal of the caries when correctly indicated.

L’objectif de ce travail était de mettre au point un modèle de culture cellulaire, afin d’étudier in vitro l’incidence sur la physiologie des cellules pulpaires et en particulier de l’odontoblaste, de biomatériaux utilisés pour traiter les effractions de pulpes dentaires. Ce modèle repose sur l’utilisation de culture sphéroïdes dont la conformation spatiale reproduit plus fidèlement l’environnement in vivo que les cultures bidimensionnelles. Après avoir élaboré le modèle sphéroïde à partir de lignées murines, des expérimentations visant à déterminer la cytotoxicité des matériaux ont été effectuées. Leurs capacités à induire la biominéralisation ont également été évaluées. La dernière partie de ce travail avait pour objectif d’immortaliser des primocultures de cellules pulpaires humaines en transfectant les gènes SV40 et hTERT, afin d’établir une lignée cellulaire / The aim of this study was to develop a cell culture model to assess in vitro the effects on the physiology of pulp cells, in particular the odontoblasts, of biomaterials used to treat dental pulp exposures. This model is based on the use of spheroid culture whose spatial configuration reproduces the in vivo environment more faithfully than do two-dimensional cultures. After developing the spheroid model from mouse lines, experiments to determine the cytotoxicity of the materials were conducted. Their ability to induce bio-mineralisation was also assessed. The last part of this work aimed to immortalise primo-cultures of human pulp cells by transfecting hTERT and SV40 genes, in order to establish a new cell line

Acetylsalicylic acid (ASA), aspirin, is a renowned NSAID that its role in the process of bone metabolism has recently come to light. However, the influence of ASA on the odontogenesis of human dental pulp cells (HDPCs) remains elusive. In search of materials that would synergize the healing potential of the dental pulp, this study aimed to investigate the role of ASA on the odontogenesis of HDPCs in vitro and the influence of ASA on TGF-ß1 liberation from dentin. HDPCs were cultured in a culture medium with different concentrations of ASA: 25, 50, 75, 100, 200 μg/mL and 0 μg/mL as a control. The mitochondria activity of HDPCs was assessed using an MTT assay. Crystal violet staining and triton were used to evaluate cell proliferation rates. ALP activity was measured with the fluorometric assay. Expressions of DSP and RUNX2 were determined with ELISA. DSP and RUNX2 mRNA levels were measured with RT‐qPCR. Alizarin red staining was conducted to evaluate the mineralized nodule formation. Dentin slices were submerged in PBS (negative control), 17% EDTA (positive control), and ASA before collecting the solution for TGF-ß1quantification by ELISA. The data were analyzed by t tests and ANOVA followed by the Tukey post hoc tests. P values < 0.05 were considered statistically significant. The results showed that 25-50 μg/mL ASA promoted mitochondria activity of HDPCs at 72h (P<0.05) and yielded significantly higher proliferation rates of HDPCs than the control at 14d and 21d (P<0.001). All concentrations of ASA promoted odontogenic differentiation of HDPCs by enhancing the mineralization and the levels of DSP, RUNX2, and their mRNA expression in a dose-dependent manner (P<0.05). Also, ASA yielded significantly higher TGF-ß1 liberation after conditioning dentin for 5min (P<0.001) and 10min (P<0.05). In conclusion, the data suggest that ASA promotes the odontogenic potential of HDPCs and TGF-ß1 liberation from dentin in vitro and might be incorporated into the novel pulp capping materials for dental tissue regeneration.

O hidróxido de cálcio (HCa), o agregado de trióxido mineral (MTA) e o óleo-resina de copaíba (COP) isoladamente apresentam características biológicas do material de capeamento pulpar direto mais apropriado. Com o pressuposto que associados poderiam originar materiais mais apropriados para serem aplicados em capeamento pulpar direto, este estudo objetivou analisar in vitro proliferação, diferenciação e migração de células-tronco de polpa de dente decíduo humano esfoliado (SHEDs) em resposta a substâncias liberadas pelo COP isolado ou associado ao HCa ou ao MTA. Proliferação, diferenciação e migração de SHEDs (Linhagem PDH3) foram analisadas através do ensaio de redução do MTT; da atividade de fosfatase alcalina (ALP), formação de nódulos mineralizados pelo ensaio de Vermelho de Alizarina e expressão dos genes (BGLAP, DSPP, DMP1 e HSP-27) pelo qRT-PCR; e, do ensaio do Scratch, respectivamente. As células foram submetidas à ação de meios condicionados pelos biomateriais, de acordo com os seguintes grupos experimentais: COP isolado (COP); HCa isolado (HCa); HCa associado ao COP (HCa+COP); MTA isolado (MTA) e MTA associado ao COP (MTA+COP). Células crescidas em meio de cultura fresco serviram de controle. Os dados foram comparados utilizando ANOVA complementado pelo teste de Tukey (p 0,05). O grupo HCa apresentou número de células viáveis significativamente menor que o dos demais grupos, inclusive o do grupo HCa+COP (p<0,01) em todos os tempos experimentais. A atividade de ALP em 14 dias foi similar em todos os grupos experimentais. Em 21 dias, o grupo COP apresentou quantidade maior de mineralização que os demais grupos (p<0,01) e o grupo HCa+COP maior que o grupo HCa (p<0,01). O gene DMP1 não foi expresso pelas células em nenhum grupo experimental. O grupo COP apresentou as menores expressões dos genes BGLAP, DSPP e HSP-27. As SHEDs do grupo MTA+COP apresentaram superexpressão dos genes BGLAP, DSPP e HSP-27, e as do grupo HCa+COP superexpressão dos genes BGLAP e HSP-27. O grupo HCa foi o único que não apresentou células em migração em todos os tempos experimentais. Os demais grupos apresentaram migração similar à do grupo Controle, exceto o grupo MTA em 12 e 24 horas. As SHEDs dos grupos HCa+COP e MTA+COP migraram significativamente mais que as dos grupos HCa e MTA, respectivamente. O COP, isolado ou em associação aos demais biomateriais, não interfere na proliferação de SHEDs e quando associado ao HCa é capaz de anular a citotoxicidade deste biomaterial isolado. O COP, isoladamente ou em associação, não interfere na atividade de fosfatase alcalina. Isoladamente, o COP induz a maior diferenciação funcional e quando associado ao HCa melhora substancialmente a diferenciação induzida por este biomaterial isolado. Os biomateriais isolados ou associados não são capazes de induzir expressão de DMP1. O COP associado aos biomateriais induz superexpressão de genes relacionados à formação de matriz extracelular e de diferenciação odontoblástica. O COP isoladamente não interfere na migração celular e, quando associado ao HCa, anula por completo a inibição de migração causada por esse biomaterial isolado. Quando associado ao MTA, o COP aumenta a velocidade de migração das células em relação ao MTA isolado. Óleo-resina de copaíba (COP) promove proliferação, diferenciação e migração de células-tronco de polpa dental sendo uma proposta de um biomaterial para capeamento pulpar. / The calcium hydroxide (CaH), the mineral trioxide aggregate (MTA) and the oil-resin copaiba (COP) by themselves have biological characteristics of the ideal direct pulp capping material. With the assumption that when associated they could originate materials more appropriated for direct pulp capping, this study aimed to analyze the in vitro proliferation, differentiation and migration of stem cells from human exfoliated deciduous teeth (SHEDs) in response to substances leached from COP alone or associated with CaH or MTA. Proliferation, differentiation and migration of SHEDs (PDH3 lineage) were analyzed through the MTT reduction assay; alkaline phosphatase (ALP) activity, mineralized nodules formation using the Alizarin Red assay and gene expression (BGLAP, DSPP, DMP1 e HSP-27) using qRT-PCR; and the Scratch assay, respectively. The cells were submitted to the culture medium conditioned by the biomaterials according to the following experimental groups: COP alone (COP); CaH alone (CaH); CaH associated to COP (CaH+COP); MTA alone (MTA) and MTA associated to COP (MTA+COP). Cells grown in fresh culture medium served as control. Data were compared by ANOVA complemented by the Tukey´s test (p 0.05). The CaH group presented number of viable cells significantly smaller (p<0.01) than those of all other experimental groups, including the CaH+COP, during whole experimental time. The ALP activity in 14 days was similar in all experimental groups. In 21 days, the COP group presented the amount of mineralization higher (p<0.01) than those of all other groups. The gene DMP1 was not expressed by the cells in all experimental groups. The COP group presented the smallest expression (p<0.01) of BGLAP, DSPP and HSP-27 genes. The SHEDs of the MTA+COP group presented superexpression of the BGLAP, DSPP and HSP-27 genes, and in the CaH+COP group the cells superexpressed the BGLAP and HSP-27 genes. The CaH group was the only one where there was no cell migration during whole experiment. Migration of all other groups was similar to that of the control group, except by the MTA group in 12 and 24 hours. The CaH+COP and MTA+COP migrated significantly more than the CaH and MTA groups, respectively. COP, alone or in association to the other biomaterials, does not interfere with the proliferation of the SHEDs, and when associated to CaH is able to annul the cytotoxicity of the CaH alone. The COP, alone or in association to the other biomaterials, does not interfere with the ALP activity. The COP alone induces the highest functional differentiation of the SHEDs and when associated to the CaH substantively improves this differentiation. The biomaterials, alone or in association, are not able to induce the expression of the DMP1 gene. The COP associated to the biomaterials induces superexpression of the genes related to the extracellular matrix formation and odontoblastic differentiation. The COP alone does not interfere with the cell migration and, when associate to CaH, completely annuls the inhibition of migration caused by this material alone. When associated to MTA the COP increases the cell migration speed compared to the effect of the MTA alone. Oil-resin copaiba (COP) promotes proliferation, differentiation and migration of stem cells from dental pulp with a proposal for a biomaterial for pulp capping.