Investigation of a modified hydraulic calcium silicate-based material - Bio-C Pulpo

Abstract This study evaluated the physicochemical, biological, and antimicrobial properties of a new hydraulic calcium silicate-based modified material, and compared it with MTA Repair HP and MTA Angelus. The materials were assessed regarding color luminosity (L), color change, radiopacity, setting time, and ISO 6876:2012 linear flow. Volumetric filling and volume change were evaluated using microcomputed-tomography (µCT). Chemical characterization after 28 days in Hank's Balanced Salt Solution (HBSS) and pH analysis were also assessed. Biological characterization of cytotoxicity and microbiological assessment were also undertaken. Shapiro-Wilk, ANOVA, Levene and post hoc analyses with Bonferroni correction were performed, adopting a 5% significance level (p <0.05). Bio-C Pulpo exhibited the highest L values after 90 days. All tested materials demonstrated color change during the analyses, and had radiopacity above 5 mm Al. MTA Repair HP set faster than Bio-C Pulpo, whereas the latter had the highest linear flow. MTA Repair HP had the highest volumetric filling in µCT analysis. Bio-C Pulpo showed the highest alkalinity during all tested periods, and the highest volumetric loss (above 9%), in comparison with MTA Repair HP and MTA Angelus. Bio-C Pulpo did not form calcium hydroxide after hydration. MTA Repair HP demonstrated the highest cytocompatibility, and Bio-C Pulpo, the highest cytotoxicity. No inhibition halos were observed for any material, and similar higher turbidity values were seen after direct contact. Composition additives used in Bio-C Pulpo modified its properties, and both the absence of calcium hydroxide deposition after hydration, and the related cytotoxicity of this material are of particular concern.

Dental discoloration caused by Grey-MTAFlow cement: analysis of its physicochemical, biological and antimicrobial properties

Abstract Tricalcium silicate-based cement are materials used in reparative and regenerative procedures in endodontics. A recently proposed formulation aimed to enhance handling during clinical use with a versatile material applicable by syringe. Although, the use of bismuth oxide as radiopacifier and grey raw powder are drawbacks considering aesthetics. Objectives Evaluate physicochemical, biological, and antimicrobial properties of Grey-MTAFlow (Ultradent) and assess whether the addition of zinc oxide (ZnO) prevents dentinal discoloration caused by bismuth oxide. Methodology Grey-MTAFlow was manipulated in 'thin' consistency for all tests. Luminosity, color change, ion migration to dentine, radiopacity, setting time, ISO 6876:2012 linear flow, volumetric lateral flow and central filling of simulated grooves scanned using micro-computed tomography (μCT), pH, calcium release, volumetric change using μCT, chemical characterisation, cytotoxicity, and antimicrobial activity were assessed. Addition of 5% ZnO to Grey-MTAFlow and a bismuth-containing experimental composition were comparatively tested. Statistical analyses used Shapiro-Wilk, T-test, ANOVA, and Kolmogorov-Smirnov (p<0.05). Results The addition of ZnO to Grey-MTAFlow prevented dentine darkening after 90 days due to bismuth migration reduction, although no statistical difference was found (p=0.863). ZnO addition significantly enhanced Grey-MTAFlow radiopacity without differences in initial setting time. Grey-MTAFlow presented an ISO linear flow of 10.9 mm and a balanced volumetric lateral flow with central filling in μCT evaluation. All compositions presented an alkaline pH after immersion. Grey-MTAFlow had a significantly higher calcium ion release after 28 days in comparison to 24 hours (p=0.011) and volumetric expansion of 0.4±1.8% after immersion. ZnO addition altered the hydrated cement matrix once calcium hydroxide (portlandite) could not be detected in characterisation. Neither of the materials produced inhibition halos nor reduced bacterial turbidity, but all presented cytocompatibility above 100%. Conclusion Grey-MTAFlow expanded after immersion and exhibited higher luminosity values after the evaluation period when ZnO was added, but chemical modifications after this addition occurred.

Comparação entre teste da urease e histopatologia na identificação do Helicobacter pylori / Comparison between urease test and histopathology in the identification of Helicobacter pylori

Introdução: o Helicobacter pylori (H. pylori) é uma bactéria gram-negativa capaz de colonizar a mucosa gástrica e predispor a diversas patologias. Para identificação do H. pylori, os testes invasivos ainda são os mais realizados, sendo que não há um teste padrão ouro aceito universalmente. A análise histológica e o teste da urease são dois dos principais métodos diagnósticos utilizados atualmente. Objetivo: o presente estudo tem como objetivo avaliar a positividade do teste da urease e da análise histopatológica, levando em consideração as variáveis como sexo, idade e patologias associadas. Métodos: trata-se de um estudo transversal de caráter quantitativo, tendo como base dados obtidos por meio de laudos de endoscopias realizadas no Hospital Universitário Santa Terezinha de Joaçaba ­ SC no período entre abril de 2014 e dezembro de 2015, assim como a partir de dados dos exames anatomopatológicos dos respectivos casos, fornecidos pelo Instituto de Patologia Joaçaba, de Joaçaba ­ SC. Os dados foram analisados e comparados através do software Microsoft Office Excel. Resultados: dos 313 pacientes que compunham a pesquisa, o teste da urease mostrou-se positivo para o H. pylori em 84 (26,83%) amostras e a avaliação histopatológica em 89 (28,43%) amostras. Em relação ao sexo, o teste da urease apresentou maior prevalência de casos positivos em homens, com 45 (53,57%) amostras. Já a histopatologia mostrou leve predominância de mulheres, com 45 (50,57%) amostras. No tocante à idade dos pacientes, ambos os métodos diagnósticos apresentaram maior frequência de positividade entre 41 e 50 anos e entre 61 e 70 anos. Quanto às lesões gástricas encontradas em pacientes com H. pylori positivo, no teste da urease, 54,76% das amostras apresentavam pangastrite enantematosa e, na avaliação histopatológica, 87,64% dos pacientes apresentavam gastrite crônica ativa. Conclusão: a comparação entre os dois métodos diagnósticos, teste da urease e histopatologia mostrou resultados equivalentes na detecção do H. pylori, sendo indicada a realização dos métodos concomitantemente. A gastrite foi a patologia mais evidenciada em ambos os métodos com H. pylori positivo; no entanto, muitos dos não acometidos também apresentavam tal patologia, o que sugere a presença de outros fatores envolvidos na gênese da afecção.

Introduction: Helicobacter pylori (H. pylori) is a gram negative bacteria capable of colonizing the gastric mucosa and predispose to various diseases. For identification of H. pylori, invasive tests are still the most accomplished, and there is no gold standard universally accepted. Histological analysis and urease test are two of the main diagnostic methods currently used. Aims: this study aims to evaluate the test positive urease and histopathology, taking into account variables such as gender, age and associated pathologies. Methods: this is a cross-sectional study of quantitative approach, based on data obtained through endoscopies reports conducted at the University Hospital Santa Terezinha de Joaçaba - SC from April 2014 to December 2015, as well as from data pathological examination of their cases, provided by the Institute of Pathology Joaçaba, Joaçaba - SC. The data were analyzed and compared using the Microsoft Office Excel software. Results: of the 313 patients who comprised the study, the urease test positive proved to H. pylori in 84 (26.83%) samples and histopathological evaluation in 89 (28.43%) samples. Regarding gender, the urease test showed a higher prevalence of positive cases in men, with 45 (53.57%) samples. Already histopathology showed slight predominance of women with 45 (50.57%) samples. Regarding the age of the patients, both diagnostic methods showed a higher frequency of positivity between 41 and 50 years and between 61 and 70 years. As for gastric lesions found in patients with H. pylori positive, the urease test, 54.76% of the samples had enanthematous pangastritis, and in histopathology, 87.64% of patients had chronic active gastritis. Conclusion: the comparison between the two diagnostic methods, urease test and histopathology showed equivalent results in the detection of H. pylori is indicated performing the methods concurrently. Gastritis was more evident pathology in both methods with H. pylori positive, however, many unaffected also had such pathology, suggesting the presence of other factors involved in the pathogenesis of the disease.

Role of cGMP and cAMP in the hemodynamic response to intrathecal sildenafil administration

INTRODUCTION: Results from our laboratory have demonstrated that intracerebroventricular administration of sildenafil to conscious rats promoted a noticeable increase in both lumbar sympathetic activity and heart rate, with no change in the mean arterial pressure. The intracerebroventricular administration of sildenafil may have produced the hemodynamic effects by activating sympathetic preganglionic neurons in the supraspinal regions and spinal cord. It is well documented that sildenafil increases intracellular cGMP levels by inhibiting phosphodiesterase type 5 and increases cAMP levels by inhibiting other phosphodiesterases. OBJECTIVE: To examine and compare, in conscious rats, the hemodynamic response following the intrathecal administration of sildenafil, 8-bromo-cGMP (an analog of cGMP), forskolin (an activator of adenylate cyclase), or dibutyryl-cAMP (an analog of cAMP) in order to elucidate the possible role of the sympathetic preganglionic neurons in the observed hemodynamic response. RESULTS: The hemodynamic responses observed following intrathecal administration of the studied drugs demonstrated the following: 1) sildenafil increased the mean arterial pressure and heart rate in a dose-dependent manner, 2) increasing doses of 8-bromo-cGMP did not alter the mean arterial pressure and heart rate, 3) forskolin did not affect the mean arterial pressure but did increase the heart rate and 4) dibutyryl-cAMP increased the mean arterial pressure and heart rate, similar to the effect observed following the intrathecal injection of the highest dose of sildenafil. CONCLUSION: Overall, the findings of the current study suggest that the cardiovascular response following the intrathecal administration of sildenafil to conscious rats involves the inhibition of phosphodiesterases other than phosphodiesterase type 5 that increase the cAMP level and the activation of sympathetic preganglionic neurons.