Evolución del germen dental trasplantado heterotópicamente en la dermis: un estudio histológico en la rata

En este estudio hemos analizado la potencialidad de desarrollo del germen dental en fase de corona. Para ello, los gérmenes dentales de rata recién nacida fueron trasplantados en las bolsas dérmicas de la oreja de ratas isogénicas. Siete y catorce días después del trasplante, se desarrollaron las estructuras morfológicas dentales típicas, con ameloblastos y odontoblastos bien diferenciados. Ulteriormente, los procesos de reacción inflamatoria del tejido huésped con infiltración celular abocaron a la desaparición de los tejidos dentales. Desde el primer momento de nuestro análisis, los trasplantes desarrollaron una dentina anómala u osteoide cuyo tamaño fue paulatinamente incrementando con el tiempo, llegando a sustituir al resto de los tejidos dentales. Esta dentina osteoide, fruto tanto de la transformación de los odontoblastos del trasplante en células de alta actividad secretora como de la inducción que el germen dental ejerce en el tejido huésped circundante; y a diferencia de la observada en estudios previos, mostró diversos grados de polimerización fibrilar, lo que nos induce a sugerir que nuestro modelo puede ser un buen medio de estudiar los mecanismos de reacción en la formación de tejidos reactivos a la lesión dental.The main goal of this study was the analysis of the developmental potentiality of tooth germ from late bell stage on, after its heterotopic placement within the skin. Teeth germs of newborn rats were grafted within a skin pouch of the ear of adult rats. Seven to fourteen days after grafting, dental germs developed normal dental structures in which ameloblasts and odontoblasts were well differentiated. Twenty to forty-one days after graft, the inflammatory host reaction destroyed the dental developed tissues by cell infiltration. The dentin of the grafts was of osteoid characteristics, and its size increased dependinng on grafting time until the complete substitution of all dental tissues. This atypical dentin showed several degrees of polymerisation from collagen fibres smooth dentin devoid near the graft a to fibres rich dentin far from the dental germ. Present results suggest that this type of dental graft could be a valuable model to study the self-development of dental tissues and the reactive mechanisms taking place after dental injuries

Osteogenic potential of different chalcones in an in vivo model: A preliminary study.

Aim. To evaluate the osteogenic potential of chalcones using the rat critical size calvarial defect. Methods. The chalcones were synthesized from acetophenone following the Claisen-Schmidt aldol condensation method by varying the substituted benzaldehydes (3,4-Cl; 4-Cl; 4-CH3; 4-OCH3, H). The five chalcone molecules were evaluated in three concentrations (1%, 5% and 10%) in comparison to control and vehicle (Vaseline) groups. The results of the remaining wound areas were calculated statistically by the ANOVA method followed by the Student - Newman - Keuls test and the histological sections were analyzed qualitatively in by light microscopy. Results. All molecules at 10% concentration showed significant bone closure compared to the control, vehicle and chalcone groups at 1% concentration (p<0.01). Active osteoblasts were observed on the repair surfaces in all groups treated with chalcones. Treatment with the C5 molecule at concentration of 10% resulted in greater bone neoformation compared to the other molecules, with features of secondary bone observed. Conclusion. The chalcones evidenced a dose-dependent osteogenic potential and C5 was more effective in bone repair

RELATO DE EXPERIENCIAS INICIAIS DO PRJETO DE EXTENSÃO ANTONIO GRAMSCI, UNIVALI, SC

O objetivo deste artigo é relatar as experiências iniciais vivenciadas, em 2015, pelo Projeto de Extensão Antonio Gramsci: fomentando a concepção ativista de educação, da Universidade do Vale do Itajaí, SC. A abordagem dialética foi adotada como método e matriz epistêmica. Na oficina-base do Projeto, intitulada Universidade, os extensionistas foram instigados para responder qual o papel da Universidade e que papel a Universidade deveria ter na sociedade brasileira. A síntese dos questionamentos deu-se na interlocução entre transformação, vontade coletiva e participação. Ancorados em Antonio Gramsci, concluíram que a produção de trabalhadores reflexivos e críticos para o Sistema Único de Saúde (SUS) exige o caráter orgânico na formação acadêmica e que a vontade coletiva é uma atividade ético-política. A execução deste Projeto expressa a natureza pública da Instituição e seu compromisso com o desenvolvimento humano

EXTENSÃO E PESQUISA NA ÁREA DA SAÚDE: UMA INTERLOCUÇÃO SOCIALMENTE CONSTRUÍDA

Apresenta uma revisão bibliográfica sobre extensão universitária, realizada no Portal Regional BVS por integrantes do Projeto de Extensão Antonio Gramsci: fomentando a concepção ativista de educação, da Universidade do Vale do Itajaí, SC. Os objetivos foram aproximar extensão e pesquisa, identificando se a dimensão histórica e a dimensão reflexivo-crítica foram exploradas em produções científicas sobre extensão, a partir dos anos 90, marco da regulamentação legal do Sistema Único de Saúde (SUS), até 2014. Na relação com os vinte e dois artigos que compuseram o universo de estudo, apreendeu-se que algumas produções científicas utilizaram a dimensão histórica e a reflexivo-crítica em descrições e/ou narrativas. O estudo reafirmou que a extensão é uma modalidade formativa basilar para a formação para o SUS, por despertar os acadêmicos para a realidade, fora dos muros, e que o diálogo entre extensão e pesquisa amplia os horizontes humanos

Transforming Growth Factor-ß1 (TGF-ß1) immunoreactivity in heterotopic grafts of adult dental apical papilla.

Objetivo: Analizar la expresión del factor transformador del crecimiento-ß1 en trasplantes heterotópicos de papila dental del incisivo de la rata adulta. Metodología: La papila apical del incisivo de 12 ratas Wistar  adultas fue trasplantada en la oreja de las mismas ratas donantes, y perfundidas 1, 3, 7 y 14 días postrasplante. El tejido fue procesado para histología convencional y para la detección inmunohistoquímica del factor transformador del crecimiento-ß1. Resultados: La papila apical trasplantada  desarrolló osteodentina. En fases tempranas postrasplante se observaron células parecidas a los odontoblastos que se organizaron en empalizada y segregaron dentina que se depositó sobre su superficie apical o secretora. Esta dentina evolucionó a osteodentina caracterizada por perder su estructura tubular e incluir a las células odontoblásticas en lagunas de su matriz. Finalmente, la osteodentina presentó procesos líticos mediados por células de tipo osteoclasto. Durante todo el proceso la expresión del factor transformador del crecimiento-ß1 se restringió a las células mesenquimales, a la matriz del trasplante y a las zonas circundantes del huésped, estando ausente en los odontoblastos, a diferencia de lo que sucede durante la odontogénesis normal. Conclusión: La diferente localización de la expresión del Factor Transformador de crecimiento ß1 entre el tejido hospedero y el trasplantado sugieren que en condiciones de trasplante heterotópico de papila dental la mediación inflamatoria del Factor Transformador de crecimiento beta1 prevalece sobre su papel morfogenético.Objective: To analyze the expression of transforming growth factor-ß1 in heterotopic grafts of adult dental apical papillae. Methodology: Adult apical papillae of Wistar rats were grafted in the ear of the same donor rats. 1, 3, 7 and 14 days after grafting, rats were perfused and the tissue containing the graft was processed for histological conventional technique and for immunohistochemical detection of transforming growth factor-ß1. Results: Heterotopically grafted apical papilla developed osteoid dentine. In an early post-grafting stage, odontoblast-like cells organized themselves in palisade and synthesized dentine. However, newly formed dentine possessed the structural appearance of reactive osteoid dentine, which was systematically destroyed by the activity of osteoclaste-like cells. Transforming Growth Factor-ß1 was observed in mesenchymal cells, extracellular matrix of the graft and surrounding host tissue, while odontoblast-like cells were systematically devoid of immunoreactivity. Conclusion: The different expression of transforming growth factor-ß1 between normal tissue and grafted tissue development suggests that in heterotopic graft conditions the inflammatory mediation of the transforming growth factor-ß1 prevails against its morphogenetic role

Osteogenic potential of different chalcones in an in vivo model: A preliminary study.

Aim. To evaluate the osteogenic potential of chalcones using the rat critical size calvarial defect. Methods. The chalcones were synthesized from acetophenone following the Claisen-Schmidt aldol condensation method by varying the substituted benzaldehydes (3,4-Cl; 4-Cl; 4-CH3; 4-OCH3, H). The five chalcone molecules were evaluated in three concentrations (1%, 5% and 10%) in comparison to control and vehicle (Vaseline) groups. The results of the remaining wound areas were calculated statistically by the ANOVA method followed by the Student - Newman - Keuls test and the histological sections were analyzed qualitatively in by light microscopy. Results. All molecules at 10% concentration showed significant bone closure compared to the control, vehicle and chalcone groups at 1% concentration (p<0.01). Active osteoblasts were observed on the repair surfaces in all groups treated with chalcones. Treatment with the C5 molecule at concentration of 10% resulted in greater bone neoformation compared to the other molecules, with features of secondary bone observed. Conclusion. The chalcones evidenced a dose-dependent osteogenic potential and C5 was more effective in bone repair

The influence of the essential oil of Melaleuca alternifolia on the healing of infected dental alveoli: a histological study in rats

The plant Melaleuca alternifolia is native to Australia. The distillation of its leaves produces an essential oil, commonly known as oil of Melaleuca, or Tea tree oil, which present antimicrobial activity. This study investigates the action of this oil on the repair process of infected dental alveoli. 48 rats were used (Rattus novergicus albinus, Wistar). After tooth extraction and posterior infection of the dental alveoli with Staphylococcus aureus, the animals were separated into three groups: Group I: curettage and irrigation with physiologic saline solution; Group II: curettage and irrigation with physiologic saline solution and topical application of rifamycin diethylamide B 25 mg; and Group III: curettage and irrigation with physiologic saline solution and topical application of oil of Melaleuca 20%. The animals were sacrificed 24 hours, 7, 14 and 21 days after the treatment with powder and the repair process of the dental alveoli was analyzed using an optical microscope. The results were submitted to qualitative and quantitative analysis and it was concluded that tea tree oil at 20% caused a delay in the repair process of infected dental alveoli in rats, as demonstrated by the presence of more necrosis area and less osteogenesis

Evaluation of direct pulp capping with a synthetic chalcone: a preliminary histological study.

<p align="justify"> ABSTRACT\ud \ud Objective: The aim of this study is to evaluate the action of the synthetic chalcone 1-phenyl-3-(4-chlorophenyl)-2-propen-1-one to induce pulp healing in rats. Material and Methods: Sixty lower first molars of male Wistar rats were divided into 3 groups (n= 20): control (no treatment); calcium hydroxide and chalcone. After relative isolation, the cavities were prepared using a sterile low-speed ¼ round dental bur. After controlling the hemorrhaging, all the pulp exposures were capped with the capping material, by groups. The cavities were sealed with glass ionomer cement and the repair process was assessed at 21 days of procedure. The data were statistically analyzed using the Fisher exact test (p<0.05). Results: Moderate inflammation was observed in all the experimental groups and significant (p<0.05) reparative dentin (tertiary) formation in the calcium hydroxide and chalcone groups. The chalcone group showed dentinal tubules and a low number of cellular inclusions (p<0.05). Conclusion: The chalcone used in this study indicates potential as an inducer of reparative dentine (tertiary) in a rat model.</p