Glass ionomer heated or not to identify bone defect created in rat calvaria / Ionômero de vidro aquecido ou não para identificação de defeitos ósseos criados em calvárias de ratos

Introduction: Some experimental models have been used to evaluate the use of biomaterials in bone regeneration. Among them are the critical size defects (CSD) created in rat calvaria. An experimental model has been described in the literature, in which "L" markings are performed on the margins of the bone defects in order to assist in the precise identification of these defects during laboratory processing and analysis of the results. In the proposed model, the "L" markings are filled with amalgam. Objective: The purpose of the present study was to evaluate the amalgam replacement of an experimental bony defect model in rat calvaria by heated or unheated glass ionomer. Material and method: 24 rats were used. A 5 mm CSD was created at each animal calvaria. Two "L" shaped markings were made 2 mm from the margins of the bone defect, filled with amalgam (Group AM), heated glass ionomer cement (Group GIh) or not (Group GI). The animals were euthanized 15 days postoperatively. The areas of the surgical defect and the L-shaped marking were histomorphometrically analyzed and the data were analyzed statistically (p <0.05). Result: There were no significant clinical, histological or methodological differences among the experimental groups. Conclusion: It can be concluded that GI can replace AM in the proposed experimental model and GI heating did not promote additional benefits.

Introdução: Alguns modelos experimentais têm sido usados para avaliar o uso de biomateriais na regeneração óssea. Entre eles estão os defeitos de tamanho crítico (DTC) criados em calvárias de ratos. Um modelo experimental foi descrito na literatura onde marcações em L são realizadas nas margens do defeito ósseo para auxiliar na identificação precisa desses defeitos durante o processamento laboratorial e análise dos resultados. No modelo experimental proposto, as marcações em "L" são preenchidas com amálgama. Objetivo: Avaliar a substituição do amálgama por ionômero de vidro aquecido ou não em um modelo experimental para identificação de defeito ósseo criado em calvária de ratos. Material e método: Foram utilizados 24 ratos. Um DTC de 5 mm de diâmetro foi criado na calvária de cada animal. Duas marcações em "L" foram realizadas a 2 mm das margens do defeito ósseo, preenchidas com amálgama (Grupo AM), ionômero de vidro aquecido (Grupo CIVaq) ou não (Grupo CIV). Os animais foram eutanasiados aos 15 dias pós-operatórios. A área do defeito cirúrgico e das marcações em "L" foram histomorfometricamente avaliadas e os dados estatisticamente analisados (p<0,05). Resultado: Não houve diferença estatisticamente significativa entre os grupos experimentais para as análises metodológicas, clínicas ou histomorfométrica realizadas. Conclusão: Dentro dos limites deste estudo, pode-se concluir que CIV pode substituir o AM no modelo experimental proposto e o aquecimento do CIV não promoveu benefícios adicionais.

Effect of Spondias mombin L. extract on the wettability, roughness, color and morphology of bovine enamel

Although Spondias mombin L. extract has an excellent antimicrobial effect against oral microorganisms, it should be clarified how it affects enamel surface properties. Aim: To evaluate the color change, wettability/contact angle, surface roughness and morphology of bovine enamel submitted to the Spondias mombin L. extract. Methods: Thirty bovine teeth were distributed into the following groups: 0.12% chlorhexidine digluconate, 1:32 Spondias mombin L. extract and distilled water. Color change (CC) was evaluated after immerging specimens into the solutions for 14 days. Surface roughness (Ra) was measured using a roughness meter; wettability/contact angles (CA) were determined by the sessile drop method, and scanning electron microscopy images were obtained to characterize the morphology (SMA). The pH of the solutions was evaluated using a pHmeter. The Ra, CA, and CC data were parametric (Kolmogorov-Smirnov; p>0.05). Two-way ANOVA (for Ra and CA) and one-way ANOVA (for CC) with Tukey's posthoc tests at a significance level of 5% were used. SMA was analyzed descriptively. Results: The Spondias mombin L. extract revealed an acidic pH, and when in contact with the bovine teeth, it increased the wettability, but it did not cause statistically significant differences in the Ra. Spondias mombin L. extract caused the highest color change. The SEM images showed differences in the specimens' surface submitted to the extract compared to the other groups. Conclusion: Spondias mombin L. extract provided negative effects on bovine enamel's surface, including a high color change and a more wettable substrate

Evaluation of the Fluorescence of Composite Resins Under an Ultraviolet Light Source / Evaluación de la Fluorescencia de Resinas Compuestas Bajo una Fuente de Luz Ultravioleta

ABSTRACT: The aim of this research is to compare the fluorescence of different trademarks of composite resins under ultraviolet light, indicating through the optical characteristics the restorative materials that best mimic the properties of dental fluorescence. In this study, nine composite resin trademarks of EA2 color were evaluated, and ten test samples were prepared for each material, totalizing ninety specimens. The specimens were produced from a bipartite aluminium matrix (10x2 mm), and then stored for 24 h in tubes of radiographic films, immersed in distilled water and after 48 h it were polished. A blind-type study (four evaluators) was used and the samples were analyzed in a dark wooden chamber where it was coupled two black lamps. In the data collection phase, the Kolmogorov-Smirnov normality test, ANOVA and Post Hoc of Tukey were used (adopting a significance level of 0.05). It was noted that the composite resin of the trademark Ultrafill was more fluorescent and Luna was statistically less fluorescent than all other materials, while Opallis and Tetric were superior to Glacier. There was no significant statistical difference among the composite resins Premissa, Point 4, Llis and Premium.

RESUMEN: El objetivo de esta investigación es comparar la fluorescencia de diferentes marcas registradas de resinas compuestas bajo luz ultravioleta, indicando a través de las características ópticas los materiales de restauración que mejor imitan las propiedades de la fluorescencia dental. En este estudio, se evaluaron nueve marcas registradas de resina de color EA2, y se prepararon diez muestras de prueba para cada material, totalizando noventa especímenes. Las muestras se produjeron a partir de una matriz de aluminio bipartita (10x2 mm), y luego se almacenaron durante 24 h en tubos de películas radiográficas, se sumergieron en agua destilada y después de 48 h se pulieron. Se utilizó un estudio de tipo ciego (cuatro evaluadores) y las muestras se analizaron en una cámara de madera oscura donde se acoplaron dos lámparas negras. En la fase de recolección de datos, se utilizaron las pruebas de normalidad KolmogorovSmirnov, ANOVA y Post Hoc de Tukey (adoptaron un nivel de significancia de 0,05). Se observó que la resina compuesta de la marca registrada Ultrafill era más fluorescente y la marca Luna fue estadísticamente menos fluorescente que todos los demás materiales, mientras que Opallis y Tetric eran superiores a Glacier. No hubo diferencias estadísticamente significativas entre las resinas compuestas Premissa, Point 4, Llis y Premium.