A polpa dentária pode responder a uma agressão pela produção de dentina reacional e reparativa. Osteopontina (OPN), proteína abundante no osso, e proteína da matriz dentinária 1 (DMP1) podem estar presentes nessas dentinas. O objetivo do trabalho foi examinar a ultra-estrutura e a presença da OPN e DMP1 na dentina induzida pela extrusão de incisivos. Os incisivos de ratos foram extruídos e depois reposicionados. Após períodos de tempo determinados, as maxilas foram processadas para MET, MEV e imunocitoquímica. Após extrusão, houve formação de dentina reacional e reparativa, as quais variaram em aspecto, espessura e células secretoras. A OPN foi observada apenas na dentina reparativa num padrão semelhante ao encontrado no osso. A DMP1 foi detectada na matriz em mineralização de todas as dentinas estudadas, mas praticamente não foi observada nas suas pré-dentinas, o que confirmou o seu papel na mineralização. Tais achados mostraram que a dentina reparativa e o osso primário, além de semelhantes morfologicamente, são também similares com relação às suas composições / Reactionary dentine (Rc) and (Rp) reparative dentine are two strategies used by the dentine?pulp complex to respond to injury. Osteopontin (OPN) and dentine matrix protein 1 (DMP1) may be present in the matrix secreted after tissue injury. The aim of the present study was to examine the ultrastructure, as well as the presence of OPN and DMP1 in Rc and Rp by provoking extrusion of the rat incisor. The right upper incisors of rats were extruded and then repositioned. After certain periods of time, the maxillae were processed for scanning and transmission electron microscopy and for immunocytochemistry. After extrusive trauma, there was formation of Rc and Rp, which varied in aspect and thickness. OPN was only detected in the Rp in a pattern similar to bone. DMP1 was immunodetected in all the dentine types, but rare colloidal gold particles were observed in predentin, that confirmed its role in mineralization. The present findings showed that Rp shares some compositional characteristics with primary bone, especially in relation to its OPN content

Made available in DSpace on 2014-06-11T19:31:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-03-23Bitstream added on 2014-06-13T19:20:24Z : No. of bitstreams: 1 mendonca_aam_dr_arafo.pdf: 4133222 bytes, checksum: f9bc8aa3130de1ab931f42b45220c045 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo do presente estudo foi avaliar a citotoxicidade do cimento de ionômero de vidro modificado por resina (CIVMR) sobre células odontoblastóides MDPC- 23 cultivadas sob discos de dentina com ou sem smear layer de diferentes espessuras. Além disto, o estudo também investigou se a permanência ou a remoção da smear layer poderia interferir na resistência de união do material com o substrato dentinário. Para isto, 40 discos de dentina com espessura de 0,4mm foram obtidos de terceiros molares humanos hígidos. Após limpeza das superfícies dos discos com ácido etilenodiamino tetra-acético (EDTA, pH 7.2), medidas de condutância hidráulica foram realizadas como forma de padronização da permeabilidade entre os discos. Lixas d’água de granulação 180 e 600 foram utilizadas para a formação da smear layer espessa e delgada, respectivamente. Desta forma, a distribuição dos discos de dentina resultou nos seguintes grupos controle e experimentais: G1M - grupo controle; G2M – Smear layer Espessa + CIVMR; G3M – Smear layer Delgada + CIVMR; G4M – Smear layer Espessa Removida + CIV; G5M – Smear layer Delgada Removida + CIVMR. Após divisão e posicionamento dos discos em câmaras pulpares artificiais, 50.000 células odontoblástóides MDPC-23 foram cultivadas sobre sua superfície pulpar. Decorridos 48 horas do cultivo, o CIVMR VitrebondTM foi aplicado sobre a superfície oclusal dos mesmos discos de dentina com ou sem smear layer. Após 24 horas, o metabolismo das células foi determinado através da avaliação da atividade da desidrogenase succínica (MTT assay). A morfologia celular foi analisada em microscopia eletrônica de varredura (MEV). Para avaliação da resistência adesiva, outros 40 terceiros molares com dentina oclusal exposta tiveram o VitrebondTM aplicado dentro das mesmas condições já descritas (com ou sem smear layer). Os grupos experimentais... / The objective of present study was to evaluate the cytotoxicity of a resin-modified glass-ionomer cement (RMGIC) on odontoblast-like cells MDPC-23 plated under dentin discs when smear layer with different thickness was removed or not. In addition, it was also investigated whether presence or not of the smear layer could change in the bond strength of material on dentin substrate. Forty dentin discs with 0.4 mm thickness were obtained from caries and restoration free human third molars. The hydraulic conductance of all dentin discs was evaluated. One hundred eighty and 600-grit silicon carbide paper were employed to created thick and thin smear layer, respectively. Thereby, the distribution of dentin disc revealed the following experimental e control groups: G1M – control group; G2M – thick smear layer + RMGIC; G3M – thin smear layer + RMGIC; G4M – Thick smear layer Removed + RMGIC; G5M – Thin smear layer Removed + RMGIC. After adapting the dentin discs in artificial pulp chambers, the odontoblast like cells MDPC-23 (50.000 cells) were plated on the pulpal surface of these discs and incubated for 48 hours. Then the RMGIC VitrebondTM was applied on the oclusal surface of the dentin discs with or without smear layer. After 24h incubation, the cell metabolism was determined through evaluation of succínic desidrogenase enzime (MTT assay). The cell morphology was investigated by scanning electronic microscopy (SEM). To evaluate bond strength, VitrebondTM was applied on the oclusal dentin surface of 40 human third sound molars treated as previously reported (with or not smear layer of different thickness). The experimental and control groups were determined: G1R – Thick smear layer + EDTA + RMGIC; G2R - Thin smear layer + EDTA + RMGIC; G3R - Thick smear layer + RMGIC; G4R - Thin smear layer + RMGIC. Each specimen characterized by the VitrebondTM applied on the exposed and treated... (Complete abstract click electronic access below)

A polpa dentária pode responder a uma agressão pela produção de dentina reacional e reparativa. Osteopontina (OPN), proteína abundante no osso, e proteína da matriz dentinária 1 (DMP1) podem estar presentes nessas dentinas. O objetivo do trabalho foi examinar a ultra-estrutura e a presença da OPN e DMP1 na dentina induzida pela extrusão de incisivos. Os incisivos de ratos foram extruídos e depois reposicionados. Após períodos de tempo determinados, as maxilas foram processadas para MET, MEV e imunocitoquímica. Após extrusão, houve formação de dentina reacional e reparativa, as quais variaram em aspecto, espessura e células secretoras. A OPN foi observada apenas na dentina reparativa num padrão semelhante ao encontrado no osso. A DMP1 foi detectada na matriz em mineralização de todas as dentinas estudadas, mas praticamente não foi observada nas suas pré-dentinas, o que confirmou o seu papel na mineralização. Tais achados mostraram que a dentina reparativa e o osso primário, além de semelhantes morfologicamente, são também similares com relação às suas composições / Reactionary dentine (Rc) and (Rp) reparative dentine are two strategies used by the dentine?pulp complex to respond to injury. Osteopontin (OPN) and dentine matrix protein 1 (DMP1) may be present in the matrix secreted after tissue injury. The aim of the present study was to examine the ultrastructure, as well as the presence of OPN and DMP1 in Rc and Rp by provoking extrusion of the rat incisor. The right upper incisors of rats were extruded and then repositioned. After certain periods of time, the maxillae were processed for scanning and transmission electron microscopy and for immunocytochemistry. After extrusive trauma, there was formation of Rc and Rp, which varied in aspect and thickness. OPN was only detected in the Rp in a pattern similar to bone. DMP1 was immunodetected in all the dentine types, but rare colloidal gold particles were observed in predentin, that confirmed its role in mineralization. The present findings showed that Rp shares some compositional characteristics with primary bone, especially in relation to its OPN content

Made available in DSpace on 2014-08-20T14:30:15Z (GMT). No. of bitstreams: 1 Dissertacao_ Marcus_Cristian_Muniz_Conde.pdf: 970527 bytes, checksum: a12676103871857eca97235b488f90c1 (MD5) Previous issue date: 2010-04-30 / Isolate high quality RNA form dental tissues is a most critical step to perform gene expression analysis. In some situations it is impossible to achieve the RNA isolation after tooth extraction, which leads to tooth discarding. Since, the aim of this experiment was to verify the effect of different teeth storage methods in the quality of RNA obtained from freshly extracted third molars. The teeth were randomly divided in five groups according to the temperature and storage time conditions. In control group RNA was isolated immediately after tooth extraction in room temperature. Experimental storage conditions evaluated were: liquid nitrogen, -80°C, -20°C (24h) and 4°C (6h). To RNA isolation, teeth were longitudinally sectioned and then pulp and pre-dentin were submerged in TRIzol®. Semi-quantitative RT-PCR was used to analyze the expression of odontoblast makers (DSPP, DMP1, and MEPE), which were normalized against the GAPDH gene. DSPP, DMP1 and MEPE were amplified in all storage conditions evaluated, regardless of storage method or tissue analyzed. Was possible to obtaining high quality RNA from pulp and dentin in all storage conditions appraised, increasing the RNA available to be used as positive control in cell differentiation studies / Extrair RNA de qualidade dos tecidos dentais é um passo crítico para a realização da análise de expressão gênica. Em algumas situações não é possível realizar o isolamento do material genético dos tecidos dentários logo após a exodontia, o que conduz ao descarte do dente. Assim, o objetivo desse estudo foi avaliar o efeito de diferentes formas de armazenamento dos dentes na qualidade do RNA odontoblástico isolado de terceiros molares recém extraídos. Os dentes foram separados de forma aleatória em cinco grupos de acordo com o tempo e a temperatura de armazenamento. No grupo controle o RNA foi isolado imediatamente após o procedimento cirúrgico em temperatura ambiente.As condições experimentais avaliadas foram: armazenamento dos dentes em nitrogênio líquido, -80°C e -20°C durante 24h e armazenamento 4°C durante 6h. Para a extração do RNA os dentes foram seccionados e então o tecido pulpar e a pré-dentina foram imersos, separadamente, em TRIzol. RT-PCR foi utilizado para analisar a efetividade dos métodos de armazenamento através da amplificação dos marcadores da diferenciação odontoblástica (DSPP, DMP1, e MEPE), que foram normalizados contra o gene constitutivo GAPDH. DSPP, DMP1, e MEPE foram amplificados de forma clara em todas as condições avaliadas, independentente do método de armazenamento, ou do tecido avaliado. Foi possível obter RNA de qualidade em polpa e dentina, em todas as condições de armazenamento avaliadas, aumentando assim a disponibilidade de RNA para ser utilizado como controle positivo em estudos de diferenciação celular

Orientador: Carlos Alberto de Souza Costa / Banca: Célia Regina Moreira Lanza / Banca: Edson Alves Campos / Banca: José Roberto Cury Saad / Banca: Marcelo Ferrarezi de Andrade / Resumo: O objetivo do presente estudo foi avaliar a citotoxicidade do cimento de ionômero de vidro modificado por resina (CIVMR) sobre células odontoblastóides MDPC- 23 cultivadas sob discos de dentina com ou sem smear layer de diferentes espessuras. Além disto, o estudo também investigou se a permanência ou a remoção da smear layer poderia interferir na resistência de união do material com o substrato dentinário. Para isto, 40 discos de dentina com espessura de 0,4mm foram obtidos de terceiros molares humanos hígidos. Após limpeza das superfícies dos discos com ácido etilenodiamino tetra-acético (EDTA, pH 7.2), medidas de condutância hidráulica foram realizadas como forma de padronização da permeabilidade entre os discos. Lixas d'água de granulação 180 e 600 foram utilizadas para a formação da smear layer espessa e delgada, respectivamente. Desta forma, a distribuição dos discos de dentina resultou nos seguintes grupos controle e experimentais: G1M - grupo controle; G2M - Smear layer Espessa + CIVMR; G3M - Smear layer Delgada + CIVMR; G4M - Smear layer Espessa Removida + CIV; G5M - Smear layer Delgada Removida + CIVMR. Após divisão e posicionamento dos discos em câmaras pulpares artificiais, 50.000 células odontoblástóides MDPC-23 foram cultivadas sobre sua superfície pulpar. Decorridos 48 horas do cultivo, o CIVMR VitrebondTM foi aplicado sobre a superfície oclusal dos mesmos discos de dentina com ou sem smear layer. Após 24 horas, o metabolismo das células foi determinado através da avaliação da atividade da desidrogenase succínica (MTT assay). A morfologia celular foi analisada em microscopia eletrônica de varredura (MEV). Para avaliação da resistência adesiva, outros 40 terceiros molares com dentina oclusal exposta tiveram o VitrebondTM aplicado dentro das mesmas condições já descritas (com ou sem smear layer). Os grupos experimentais... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of present study was to evaluate the cytotoxicity of a resin-modified glass-ionomer cement (RMGIC) on odontoblast-like cells MDPC-23 plated under dentin discs when smear layer with different thickness was removed or not. In addition, it was also investigated whether presence or not of the smear layer could change in the bond strength of material on dentin substrate. Forty dentin discs with 0.4 mm thickness were obtained from caries and restoration free human third molars. The hydraulic conductance of all dentin discs was evaluated. One hundred eighty and 600-grit silicon carbide paper were employed to created thick and thin smear layer, respectively. Thereby, the distribution of dentin disc revealed the following experimental e control groups: G1M - control group; G2M - thick smear layer + RMGIC; G3M - thin smear layer + RMGIC; G4M - Thick smear layer Removed + RMGIC; G5M - Thin smear layer Removed + RMGIC. After adapting the dentin discs in artificial pulp chambers, the odontoblast like cells MDPC-23 (50.000 cells) were plated on the pulpal surface of these discs and incubated for 48 hours. Then the RMGIC VitrebondTM was applied on the oclusal surface of the dentin discs with or without smear layer. After 24h incubation, the cell metabolism was determined through evaluation of succínic desidrogenase enzime (MTT assay). The cell morphology was investigated by scanning electronic microscopy (SEM). To evaluate bond strength, VitrebondTM was applied on the oclusal dentin surface of 40 human third sound molars treated as previously reported (with or not smear layer of different thickness). The experimental and control groups were determined: G1R - Thick smear layer + EDTA + RMGIC; G2R - Thin smear layer + EDTA + RMGIC; G3R - Thick smear layer + RMGIC; G4R - Thin smear layer + RMGIC. Each specimen characterized by the VitrebondTM applied on the exposed and treated... (Complete abstract click electronic access below) / Doutor

Background The revitalization or regeneration of the dental pulp is a preferable goal in current endodontic research. In this study, human dental pulp cell (DPC) spheres were applied to human root canal samples to evaluate their potential adoption for physiological tissue-like regeneration of the dental root canal by odontoblastic differentiation as well as cell-induced mineral formation. Methods DPC were cultivated into three-dimensional cell spheres and seeded on human root canal specimens. The evaluation of sphere formation, tissue-like behavior and differentiation as well as mineral formation of the cells was carried out with the aid of optical light microscopy, immunohistochemical staining and scanning electron microscopy (SEM). Results Spheres and cells migrated out of the spheres showed an intense cell-cell- and cell-dentin-contact with the formation of extra cellular matrix. In addition, the ingrowth of cell processes into dentinal tubules and the interaction of cell processes with the tubule walls were detected by SEM-imaging. Immunohistochemical staining of the odontoblast specific matrix proteins, dentin matrix protein-1, and dentin sialoprotein revealed an odontoblast-like cell differentiation in contact with the dentin surface. This differentiation was confirmed by SEM-imaging of cells with an odontoblast specific phenotype and cell induced mineral formation. Conclusions The results of the present study reveal the high potential of pulp cells organized in spheres for dental tissue engineering. The odontoblast-like differentiation and the cell induced mineral formation display the possibility of a complete or partial “dentinal filling” of the root canal and the opportunity to combine this method with other current strategies.

Background The revitalization or regeneration of the dental pulp is a preferable goal in current endodontic research. In this study, human dental pulp cell (DPC) spheres were applied to human root canal samples to evaluate their potential adoption for physiological tissue-like regeneration of the dental root canal by odontoblastic differentiation as well as cell-induced mineral formation. Methods DPC were cultivated into three-dimensional cell spheres and seeded on human root canal specimens. The evaluation of sphere formation, tissue-like behavior and differentiation as well as mineral formation of the cells was carried out with the aid of optical light microscopy, immunohistochemical staining and scanning electron microscopy (SEM). Results Spheres and cells migrated out of the spheres showed an intense cell-cell- and cell-dentin-contact with the formation of extra cellular matrix. In addition, the ingrowth of cell processes into dentinal tubules and the interaction of cell processes with the tubule walls were detected by SEM-imaging. Immunohistochemical staining of the odontoblast specific matrix proteins, dentin matrix protein-1, and dentin sialoprotein revealed an odontoblast-like cell differentiation in contact with the dentin surface. This differentiation was confirmed by SEM-imaging of cells with an odontoblast specific phenotype and cell induced mineral formation. Conclusions The results of the present study reveal the high potential of pulp cells organized in spheres for dental tissue engineering. The odontoblast-like differentiation and the cell induced mineral formation display the possibility of a complete or partial “dentinal filling” of the root canal and the opportunity to combine this method with other current strategies.