Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2000. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2001. / Härtill 4 uppsatser.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 139-150). Also available via the Internet.

Thesis (Ph.D.)--University of Delaware, 2009. / Principal faculty advisors: Babatunde Ogunnaike, Dept. of Chemical Engineering, and Ulhas P. Naik, Dept. of Biological Sciences. Includes bibliographical references.

Orientador: Mario Fernando de Goes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-17T19:30:23Z (GMT). No. of bitstreams: 1 Caiado_AnaCarolinaRochaLima_D.pdf: 1063756 bytes, checksum: a22bf4dcecddb8c72dec6a8cc41089d1 (MD5) Previous issue date: 2010 / Resumo: O objetivo deste estudo foi avaliar: (1) a integridade marginal (IM) de pinos de fibra de vidro anatomicamente reembasados (PA) e pinos de fibra de vidro (PC) cimentados com diferentes materiais; (2) a dureza Knoop de cimentos resinosos duais usando a técnica PA e PC na presença e ausência de luz; e (3) a IM entre cimento resinoso autoadesivo e as paredes do canal radicular após a fixação de PC e PA reembasados com resina à base de metacrilato ou silorano. Os estudos 1 e 2 empregaram raízes de incisivos bovinos distribuídos aleatoriamente em 8 grupos de acordo com a técnica usada (PC ou PA), o cimento empregado (Rely X ARC (R) e Unicem (U), 3M ESPE), e o modo de ativação do cimento (químico (Q) ou dual (D)). No estudo 3, raízes bovinas foram distribuídas em 6 grupos de acordo com a técnica usada (PC ou PA), o material usado para reembasar o PA (resina composta à base de metacrilato ou silorano), e o modo de ativação (Q ou D). Após 48 horas, as raízes foram seccionadas longitudinalmente, polidas e demarcadas de acordo com seus terços (cervical (C), médio (M), Apical (A)). A IM entre o cimento resinoso e a dentina do canal radicular após a cimentação de pinos de fibra de vidro foi avaliada nos estudos 1 e 3. Para isso, réplicas foram confeccionadas a partir das amostras e essas foram então imersas em solvente para a confecção de novas réplicas. As amostras foram analisadas usando microscopia eletrônica de varredura (MEV) e a percentagem de margens contínuas (%) foram determinadas como uma medida de IM. No estudo 2, após o polimento as amostras, foram levadas a um microdurômetro (50g por 5 min) para obter os valores de dureza Knoop. Os estudos 1 e 3 revelaram que a IM foi estatisticamente maior para PA do que para PC antes e após imersão em solvente para todos os terços do canal radicular. No artigo 1, quando o PA foi empregado, a IM de U(73% ±36) foi maior do que para R(42% ±46). Nenhuma diferença entre cimentos foi observada quando PC foi usado (U= 8% ±15; R= 9% ±18). A IM foi maior para a ativação Q(43% ±44) do que D (22.9% ±35.5), independente da técnica ou do cimento usado. O estudo 2 revelou que a interação dos fatores (técnica, cimento e modo de ativação) foram estatisticamente significativos no terço C e M do canal (C: p= 0.0393, M: p= 0,0177), mas não no A, que foi apenas afetado pelo modo de ativação (p=0.0015). O estudo 3 mostrou que a IM não foi afetada pelo material usado para reembasar o PA nos 3 terços (C: p<.0001; M: p<.0001; A: p=0.0062) e o modo de ativação do cimento (C: p=0.9306; M: p=0.0756; A: p=0.3447). Conclusão: A integridade marginal foi significativamente aumentada por: (1) emprego do PA (2) ativação Q do cimento ;(3) o uso associado do pino anatômico e de um cimento auto-adesivo. O reembasamento do PA afetou a dureza knoop do cimento subjacente nos terços C e M, mas não no A; (5) O material usado para reembasar o pino anatômico não afetou significativamente a IM / Abstract: Preformed fiber-reinforced root canal posts have increased in popularity as an alternative to metal posts. This is partly due to a modulus of elasticity that is closer to that of dentin when compared to metal posts. The employment of materials with similar mechanical properties creates a homogenous biomechanical unit which favors uniform stress distribution and reduces the incidence of root fracture and micro-leakage. In spite of positive outcomes in terms of laboratory and clinical results documented in retrospective and prospective studies, major concerns around bonding procedures still remain. The dislodging of fiber posts from the root canal continues to be the main cause of failure of fiber post-retained restorations. A chair side clinical procedure that involves the confectioning of an anatomically shaped relined post was developed to compensate the mismatch between fiber post and post space, offering a more conservative preparation for the remaining root structure. This technique has been described to compensate light limitations because the composite resin used to anatomically shape the fiber-post is light-cured immediately after relining, outside of the root canal, before cementation. Among the possible advantages of light curing the relined fiber post outside of the root canal and reducing the cement layer thickness are the increase of monomer conversion, the reduction of polymerization shrinkage, and the presence of bubbles in the cement layer. Therefore, the aim of the present study was to: (1) Compare marginal integrity of conventional and anatomically relined fiberposts to root canal dentin using scanning electron microscopy; (2) Evaluate and compare Knoop's Hardness of two dual-cure cements with for conventional and anatomically relined fiberposts in the presence and absence of light; and (3) Compare the marginal integrity between a self adhesive cement and root canal dentin after cementation of anatomic fiber posts relined with either methacrylate or silorane based composite resin. It was possible to conclude that: (1) Marginal integrity of relined fiber posts to root dentin is superior compared to conventional fiber posts; (2) The technique, activation mode and cement type were factors that affected Knoop hardness for cervical and middle root thirds. The apical third was exclusively influenced by activation mode; and (3) The material used for anatomically relining fiber posts did not significantly affect marginal integrity to root canal walls / Doutorado / Endodontia / Doutor em Cíinica Odontológica

A very important aspect for the functioning of an organism is that cells adapt their behaviour to external stimuli. They continuously interact with their environment, and biochemical and physical cues can activate cellular signalling, which leads to changes in cell behaviour such as proliferation and shape. Understanding cells' interactions with their environment is also important for understanding diseases. For example mechanosensing, which is the sensing of the cell's mechanical environment, has been associated with cancer development. In order for a cell to be able to sense its mechanical environment, it needs to form attachments to the environment. In my thesis, I have worked on three different tasks: the development of a new measurement technique and the study of initial cell adhesion and of cell spreading. When a cell from suspension first comes into contact with a substrate, it forms initial attachment bonds with proteins on the substrate surface. These bonds are mediated through integrins, which are transmembrane heterodimers, binding to the cell's environment on one side and to the cell's cytoskeleton on the other side. I study this initial cell attachment by measuring the force needed to detach cells, called cell adhesion strength. For these experiments I built a detachment device, which allows the detachment of cells from a substrate by vibrating the substrate in liquid. The device combines cell incubation, detachment and imaging. I measured the dependence of initial integrin bond formation on external factors such as incubation temperature and substrate stiffness. Once initial integrin bonds are formed, many different proteins are recruited to the adhesion site in order to form stronger adhesions. Amongst these proteins are signalling proteins, which direct the behaviour of the cell as a whole. One of the first cellular reactions to a substrate after initial integrin binding is cell spreading. This can be seen by the cell changing its shape from spherical to dome-like on the substrate. Because cell spreading is a very early response of a cell to a substrate, the onset time of spreading can be used as a quantitative measure for the time it takes the cell to sense a substrate and signal shape change. In my work, I look at the distribution of the time of initial cell spreading in a population of cells. I measure this distribution under different growth conditions such as pH, change of incubation medium from DMEM to PBS, substrate stiffness and incubation temperature. In my detachment experiments, I observe that vibration accelerates cell spreading in those cells which remain on the substrate. This is a connection between the detachment experiments and the cell spreading experiments and it shows how cells react to external forces. By changing the medium temperature in the cell detachment and cell spreading experiments, I am able to analyse the kinetics of these two processes. I use a signalling network model to analyse the internal cellular signalling path that leads from a spherical to a spread cell.