Mechanism of action of Bioactive Endodontic Materials

Abstract A continuous search for bioactive materials capable of supporting the replacement of damaged pulp tissue, with effective sealing potential and biocompatibility, has represented the attention of studies over the last decades. This study involves a narrative review of the literature developed by searching representative research in PUBMED/MEDLINE and searches in textbooks associated with the mechanism of action of bioactive materials (calcium hydroxide, mineral trioxide aggregate (MTA), and calcium silicate cements). The reflective analysis of the particularities of the chemical elements of these materials, considering the tissue and antibacterial mechanism of action, allows a better understanding of the characteristics and similarities in their tissue responses. Calcium hydroxide paste remains the antibacterial substance of choice as intracanal dressing for the treatment of root canal system infections. Calcium silicate cements, including MTA, show a favorable biological response with the stimulation of mineralized tissue deposition in sealed areas when in contact with connective tissue. This is due to the similarity between the chemical elements, especially ionic dissociation, the potential stimulation of enzymes in tissues, and the contribution towards an alkaline environment due to the pH of these materials. The behavior of bioactive materials, especially MTA and the new calcium silicate cements in the biological sealing activity, has been shown to be effective. Contemporary endodontics has access to bioactive materials with similar properties, which can stimulate a biological seal in lateral and furcation root perforations, root-end fillings and root fillings, pulp capping, pulpotomy, apexification, and regenerative endodontic procedures, in addition to other clinical conditions.

Resumo Uma busca contínua de materiais bioativos com capacidade de substituir o tecido pulpar danificado, com efetiva capacidade de selamento e biocompatibilidade, tem representado a atenção e foco de muitos estudos ao longo das últimas décadas. Este estudo envolve uma revisão narrativa da literatura desenvolvida por meio de pesquisas representativas encontradas no PUBMED/MEDLINE e pesquisas em livros didáticos associadas ao mecanismo de ação de materiais bioativos (hidróxido de cálcio, agregado de trióxido mineral (MTA) e cimentos de silicato de cálcio). A presente análise reflexiva das particularidades dos elementos químicos destes materiais bioativos, considerando o mecanismo de ação tecidual e antibacteriano, possibilita um melhor entendimento das características e similaridades no comportamento tecidual. A pasta de hidróxido de cálcio continua sendo a substância antibacteriana de escolha como medicação intracanal para o tratamento das infecções do sistema de canais radiculares. Este fato se deve a disponibilidade química de íons cálcio e hidroxila do hidróxido de cálcio aos tecidos, e a inibição enzimática bacteriana. Os cimentos de silicato de cálcio, dentre os quais inclui o MTA, apresentam uma resposta biológica favorável ao estímulo à deposição de tecido mineralizado nas áreas seladas e em contato com tecido conjuntivo. Este fato é decorrente da similaridade entre os elementos químicos, em especial devido a dissociação iônica, ao potencial estímulo de enzimas teciduais, e a contribuição com um meio alcalino decorrente do pH destes materiais. O comportamento dos materiais bioativos, em especial o MTA e os novos cimentos de silicato de cálcio na atividade de selamento biológico mostraram efetivos. A endodontia contemporânea atualmente conta com o potencial de materiais bioativos com propriedades análogas capaz de estimular o selamento biológico em perfurações radiculares laterais e de furca, em obturações radiculares, capeamento pulpar, pulpotomia, apicificação e procedimentos endodônticos regenerativos, além de outras condições clínicas.

Eficacia Antimicrobiana del Cemento Portland Comparado con el Mineral Trióxido Agregado Frente a Enterococcus faecalis y Candida albicans

RESUMEN: El objetivo del estudio experimental in vitro fue evaluar la eficacia antimicrobiana del cemento Portland (CP) comparado con el Mineral Trióxido Agregado (MTA) frente a cepas de Enterococcus faecalis (E. faecalis) y Candida albicans (C. albicans) a las 24, 48 y 72 horas después del sembrado. Para ello se utilizó la técnica de difusión en agar. La capa base fue realizada con el Agar Müller-Hinton en el que se hicieron agujeros de 6 mm de diámetro a fin de contener los cementos de estudio y medir posteriormente la zona de inhibición microbiana alrededor de los materiales mediante un calibrador vernier digital. Se utilizó la prueba T de Student para comparar la diferencia entre el CP y MTA y el análisis de ANOVA para evaluar las diferencias entre los tres tiempos de estudio. Los resultados mostraron que tanto frente a E. faecalis y C. albicans el CP tuvo un mayor halo de inhibición que el MTA, siendo estas diferencias estadísticamente significativas (p0.05). Asimismo, la C. albicans presentó valores mayores de inhibición que el E. faecalis en los dos cementos estudiados. Se concluyó que el CP tuvo mayor eficacia antimicrobiana que el MTA independientemente del tiempo evaluado.

ABSTRACT: The aim of the experimental in vitro study was to evaluate the antimicrobial efficacy of Portland cement (CP) compared with Mineral Trioxide Aggregate (MTA) against Enterococcus faecalis (E. faecalis) and Candida albicans (C. albicans) strains at 24, 48 and 72 hours after sowing. For this, the agar diffusion technique was used. The base layer was made with Müller-Hinton Agar in which 6 mm diameter holes were made in order to contain the study cements and subsequently measure the zone of microbial inhibition around the materials using a digital vernier caliper. The Student's t test was used to compare the difference between CP and MTA and the ANOVA analysis to evaluate the differences between the three study times. The results showed that both against E. faecalis and C. albicans, CP had a greater inhibition than MTA, these differences being statistically significant (p 0.05). Likewise, C. albicans presented higher inhibition values than E. faecalis in the two cements studied. It was concluded that CP had greater antimicrobial efficacy than MTA regardless of the time evaluated.

Formulação, análise físico-química e microbiológica de cimentos endodônticos bioativos / Formulation, physicochemical and microbiological analysis of bioactive endodontic cements

Os cimentos endodônticos bioativos apresentam inúmeras aplicações clínicas, devido as suas propriedades biológicas, como a bioatividade; alta capacidade de vedação; ação antimicrobiana; liberação de íons cálcio, além de apresentar resposta inflamatória reduzida ou ausente. Baseada nesses benefícios, a presente pesquisa objetivou desenvolver e caracterizar cimentos endodônticos bioativos de baixo custo e efetividade antimicrobiana para uso na endodontia. Para isso, foram preparadas algumas formulações contendo cimentos finos, escória moída e celulose. Esses cimentos testes foram comparados com o MTA branco reparador da Angelus®. Sendo então divididos em quatro grupos: Grupo 1 (cimento fino cinza com escória moída cinza - MZVI e celulose); Grupo 2 (cimento branco cinza, escória moída branca - MPW e celulose); Grupo 3 (cimento fino branco e celulose) e Grupo 4 (MTA branco, Angelus ­ controle positivo). As amostras de cada grupo foram submetidas às análises de Difração de Raio-X (DRX), Análise Termogravimétrica (TG), Termogravimetria Derivada (DTG), Microscopia Eletrônica de Varredura (MEV), Potencial hidrogeniônico (pH), Picnometria, Espectroscopia de Infravermelho com Transformada de Fourier (FTIR) e Potencial Antibacteriano contra Enterococcus faecalis por meio do teste de difusão em ágar. Os testes estatísticos foram realizados utilizando o SPSS. As diferenças entre os grupos foram verificadas por meio do teste ANOVA com post hoc de Tukey, estatística descritiva e análises gráficas. Após a avaliação dos dados podese observar, principalmente, a presença de hidróxido de cálcio, silicato dicálcico, silicato tricálcico, aluminato tricálcico e carbonato de cálcio. Além disso, os cimentos apresentaram pH alcalino, ação antimicrobiana contra Enterococcus faecalis e na análise do MEV foi possível observar partículas de dimensões irregulares com uma distribuição heterogênea na matriz polimérica, contrastando com a homogeneidade apresentada pelo MTA. Porém, nas demais características, os cimentos apresentaram, de forma geral, grande semelhança com o MTA branco da Angelus, com maior destaque para o grupo 2. Assim, pode-se concluir que é possível formular cimentos bioativos, reutilizando escórias e mantendo as propriedades físico-químicas e antimicrobiana presentes no MTA (AU).

Bioactive endodontic cements have numerous clinical applications due to their biological properties, such as bioactivity; high sealing capacity; antimicrobial action; realease of calcium ions, also having a reduced or no inflammatory response. Based on these benefits, the present research aimed to develop and characterize low cost bioactive endodontic cements and antimicrobial effectiveness for endodontic use. For this, some formulations containing fine cements, ground slag and cellulose were prepared. These test cements were compared with Angelus® repairing white MTA. It was then divided into four groups: Group 1 (gray fine cement with gray ground slag - MZVI and cellulose); Group 2 (white gray cement, white ground slag - MPW and cellulose); Group 3 (white fine cement and cellulose) and Group 4 (white MTA, Angelus ­ positive control). The samples from each group were subjected to X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Derived Thermogravimetry (DTG), Scanning Electron Microscopy (SEM), Hydrogen Potential (pH), Picnometry, Infrared Spectroscopy with Fourier Transform (FTIR) and Antibacterial Potential against Enterococcus faecalis through the agar diffusion test. Statistical tests were performed using SPSS. Differences between groups were verified using the ANOVA test with Tukey's post hoc, descriptive statistics and graphical analyses. After evaluating the data, it was possible to observe, mainly, the presence of calcium hydroxide, dicalcium silicate, tricalcium silicate, tricalcium aluminate and calcium carbonate. In addition, the cements showed alkaline pH, antimicrobial action against Enterococcus faecalis and in the SEM analysis it was possible to observe particles of irregular dimensions with a heterogeneous distribution in the polymer matrix, contrasting with the homogeneity presented by MTA. However, in the other characteristics, the cements showed, in general, great similarity with the white MTA from Angelus, with greater emphasis on group 2. Thus, it can be concluded that it is possible to formulate bioactive cements, reusing slag and maintaining the MTA physicochemical and antimicrobial properties (AU).

Avaliação do pH, liberação de íons cálcio e atividade antimicrobiana do cimento Portland associado a Bambusa textilis em diferentes proporções / Analysis of pH, calcium ion release and antibacterial activity of Portland cement associated to Bambusa textilis in different proportion

Introdução: há uma busca incessante por agentes fitoterápicos na medicina e odontologia. Dentro da endodontia, busca-se uma substância que potencialize os efeitos biológicos e antimicrobianos do hidróxido de cálcio como curativo de demora. Não há na literatura relatos sobre a associação do cimento Portland com a Bambusa textilis, uma planta nativa da China, onde é usada na elaboração de medicamentos, pois se trata de uma fonte importante de resinas, sendo, portanto utilizadas por seu poder anti-inflamatório, anticatarral, anticonvulsivante e antitérmico. Sabendo da semelhança do cimento Portland com o MTA, e que esse ultimo apresenta bons resultados físico-químicos, surge a dúvida da possibilidade da associação, com a finalidade de melhorar as atividades antimicrobianas, e a interferência na liberação de íons cálcio e hidroxila. Objetivo: avaliar o pH, liberação de íons cálcio e atividade antimicrobiana do cimento Portland associado a Bambusa textilis em diferentes proporções. Metodologia: os cimentos experimentais foram 3 g Cimento Portland + 1,2 ml de Bambusa textilis (G1); 3 g Cimento Portland + 0,6 ml de água + 0,6 de Bambusa textilis (G2); 3 g Cimento Portland + 0,9 ml água + 0,3 ml de Bambusa textilis (G3); 3 g Cimento Portland puro (controle) + 1,2 ml água (G4); Bambusa textilis (controle): 20 microlitros por poço. Para os testes de pH e liberação de íons cálcio foram utilizados tubos de polietileno, os quais foram preenchidos com os cimentos e imersos em frascos contendo água deionizada. As mensurações foram por meio de um peagâmetro e espectrofotômetro de absorção atômica. Para a análise da atividade antimicrobiana, foi utilizada a técnica de difusão radial com cepa de Enterococcus faecalis. Os halos de inibição foram mensurados com auxílio de um paquímetro digital. A análise estatística foi realizada pelo teste ANOVA para comparação global, e teste de Tukey para comparações individuais, com significância de 5%. Resultados: os valores de pH se mostraram próximos ao neutro para todos os grupos em todos os períodos experimentais. Houve liberação de íons cálcio e ocorreu em todos os grupos e em todos os períodos experimentais. Em relação à atividade antimicrobiana, nenhuma das proporções apresentou atividade. Conclusão: a associação da Bambusa textilis ao cimento Portland manteve seu pH e liberação de íons cálcio, mas não potencializou sua atividade antimicrobiana frente ao E. faecalis. (AU)

Introduction: there is a search for phytotherapeutic agents in medicine and dentistry. Within endodontics, a substance that potentiates the biological and antimicrobial effects of calcium hydroxide as a delay dressing is sought. There are no reports in the literature about the association of Portland cement with Bambusa textilis, a plant native to China, where it is used in the manufacture of medicines, since it is an important source of resins and is therefore used for its anti-inflammatory power, anticonvulsive and antipyretic. Knowing the similarity of the Portland cement with the MTA, and that the latter presents good physicochemical results, the possibility of the association arises, with the purpose of improving the antimicrobial activities, and the interference in the release of calcium and hydroxyl ions. Aim: to analyze the pH, calcium ion release and antibacterial activity of Portland cement associated to Bambusa textilis in different proportions. Methods: the experimental cements ́ proportions were: 3 g of Portland cement + 1.2 ml of Bambusa textilis (G1); 3 g of Portland cement + 0.6 ml of water + 0.6 of Bambusa textilis (G2); 3 g of Portland cement + 0.9 ml of water + 0.3 ml of Bambusa textilis (G3); 3 g of pure Portland cement (control group) + 1.2 ml of water (G4); Bambusa textilis (control group): 20 µLper well. Polyethylene tubes filled with the cements and immersed in deionized water were employed. Calcium ion release was analyzed using an atomic absorption spectrophotometer and the change in pH was determined through a pH meter. For the analysis of antibacterial activity, a digital radial diffusion assay with a Enterococcus faecalis strain was utilized. Statistical analysis was performed using ANOVA and Tukey's tests. The level of significance was set at P = 0.05. Results: pH values were close to neutral for all of the experimental groups in all periods evaluated. Calcium ion release was observed in all experimental groups and evaluation periods. Regarding the antibacterial activity, this property could not be detected in any of the proportions used in this study. Conclusions: the association of Bambusa textilis to Portland cement, preserved its pH values and its calcium ion release property. Nevertheless, it did not improve its antibacterial activity against E. faecalis strains. (AU)

Análisis químico elemental y de fases por medio de PIXE, DSC, TGA y DRX en MTA Angelus® y un cemento Portland blanco / Elemental chemical composition and phase analysis by means of PIXE, DSC, TGA, and DRX of MTA Angelus® and a white Portland cement

Resumen: El mineral trióxido agregado (MTA) es un cemento usado principalmente para sellar perforaciones en órganos dentales debido a que endurece en presencia de humedad, está compuesto por cemento Portland y trióxido de bismuto. Objetivo: Analizar y comparar por medio de PIXE, DSC, TGA y DRX la composición química elemental y de fases del cemento MTA Angelus® y de un cemento Portland blanco (CPB-CA). Material y métodos: MTA Angelus® blanco y un cemento Portland blanco fueron analizados con PIXE en un acelerador de partículas; el análisis de fases cristalinas se realizó por medio de DRX y contrastado los picos con los de base de datos del ICDD, el DSC se realizó en un calorímetro hasta 900 °C. Resultados: PIXE detectó como elementos de mayor porcentaje fueron aluminio, silicio y calcio para ambos cementos; habiendo diferencias en los porcentajes de azufre; el bismuto sólo se detectó en MTA Angelus®. Se detectaron como elementos traza cobre y estroncio en el MTA Angelus®, además de zirconio en CPB-CA. La relación entre silicio-calcio y silicio-aluminio en los dos cementos es similar. Se identificaron tres fases cristalinas en ambos cementos, silicato dicálcico, silicato tricálcico y aluminato tricálcico; sin embargo, se identificó Bismita en el MTA Angelus® y sulfato de calcio en forma de yeso en CPB-CA, que se logró corroborar con la ayuda de la técnica DSC. Conclusiones: Se logró observar la baja cantidad de yeso en MTA Angelus® por medio de la calorimetría. Tanto las fases cristalinas como la composición química elemental son similares en ambos cementos.

Abstract: Mineral trioxide aggregate (MTA) is a cement mainly used to seal tooth perforations; this is due to the fact that it hardens when in presence of humidity. It is composed of Portland cement and Bismuth trioxide. Objective: To analyze and compare with PIXE, DSC, TGA and DRX elementary chemical and phase composition of MTA Angelus® cement with a white Portland cement (WPC). Material and methods: MTA Angelus® white and a white Portland cement were analyzed with PIXE in a particle accelerator, phase analyses were conducted with XRD contrasting peaks with those in the ICDD database. DSC was conducted in a calorimeter up to 900 oC. Results: PIXE detected the following as greater percentage elements: aluminum, silica and calcium for both cements. Differences were found with sulfur percentages; Bismuth was only detected in MTA Angelus®. Trace elements of copper and strontium were detected in MTA Angelus® and zirconium in WPC. Relationship between silica-calcium and silica-aluminum was similar in both cements. In both cements, three crystalline phases were detected: dicalcium silicate, tricalcium silicate and tricalcium aluminate. Nevertheless, Bismite was identified in MTA Angelus® and calcium sulfate in the form of gypsum in WPC, this was corroborated with DSC technique. Conclusions: In MTA Angelus®, low gypsum amounts were observed by means of calorimetry. In both cements, crystalline phases and elemental chemical composition were similar.

Materiais usados em retro-obturações: comparação entre cimento de ionômero de vidro fotopolimerizável e cimento de portland / Materials used in retrograde obturations: comparison between light-cured glass ionomer and Portland cement

O objetivo deste estudo foi comparar, por meio de um teste in vitro, se ocorre infiltração ou não pelo corante azul de metileno a 0,2% em retro-obturações seladas com cimento ionômero de vidro fotopolimerizável e cimento Portland. Quarenta dentes unirradiculares receberam tratamento endodôntico convencional. As coroas foram removidas com um corte na junção cemento-esmalte, perpendicular ao longo eixo do dente e um corte horizontal de 2 a 3 mm do ápice. As raízes foram revestidas externamente, com duas camadas de esmalte de unha. Foi realizada uma cavidade apical para retro-obturação dos condutos. A amostra foi dividida em 2 grupos: Grupo 1 - isolamento apical com cimento de ionômero de vidro fotopolimerizável e Grupo 2 - isolamento com cimento Portland. Logo após a realização da obturação retrógrada, as amostras foram submetidas à imersão parcial em corante azul de metileno a 0,2% de pH neutro, durante 24 horas. As amostras foram lavadas em água corrente por 12 horas e 10 dias de secagem. Depois, as raízes foram seccionadas longitudinalmente no sentido mésio-distal e observadas por 2 examinadores independentes, com o auxílio de uma lupa com aumento de duas vezes. Foi utilizado o teste estatístico qui-quadrado para verificar as hipóteses. No total de 20 dentes retro-obturados com ionômero, apenas 1 deles foi infiltrado. Entretanto, com relação ao cimento Portland, em 18 dentes, houve infiltração com azul de metileno 0,2%. Nesse teste in vitro, os resultados apontam que o selamento apical com ionômero de vidro é superior ao selamento com cimento Portland.

The objective of this study was to compare through an in vitro test, if infiltration occurs or not by 0.2% methylene blue dye in retrograde obturations sealed with glass ionomer light-curing cement and Portland cement. Forty single-rooted teeth recieved conventional endodontic treatment. The crowns were removed with a cut at the cementoenamel junction perpendicular to the long axis of the tooth and a horizontal cut 2 to 3 mm from the apex. The roots were externally coated with two layers of nail polish. An apical cavity was performed for retrofilling of the conduits. The sample was divided into 2 groups: Group 1 with apical insulated glass ionomer light-curing cement and Group 2 with insulation with Portland cement. After the completion of the retrograde filling, the samples were subjected to partial immersion of 0.2% methylene blue dye in neutral pH for 24 hours. The samples were washed in running water for 12 hours and then 10 days of drying. After the roots were split lengthwise mesiodistally and observed by two independent examiners with the aid of a magnifying glass with an increase of twice. The chi-square statistical test was used to verify the hypotheses. Of the total of 20 teeth with retrograde obturations using ionomer, only one tooth was infiltrated, since with respect to Portland cement in 18 teeth there was infiltration with 0.2% methylene blue. In this in vitro test, the results suggest that the apical seal with glass ionomer is better than the sealing with Portland cement.

Efecto osteoinductor del mineral trióxido agregado versus el cemento Portland tipo I sobre lesiones óseas mandibulares

Introducción: Estudio experimental donde se procuró determinar el efecto osteoinductor del mineral trióxido agregado (MTA) versus el cemento Portland tipo I sobre lesiones óseas mandibulares. Metodología: Se emplearon 12 conejos machos de la raza New Zealand de 3 meses de edad, los cuales fueron divididos en 4 grupos iguales. Todos los conejos fueron anestesiados utilizando pentobarbital sódico. Se procedió a la incisión en la piel mandibular para exponer el hueso sobre el que se realizó 3 cavidades de 3mm cada una. En una cavidad se colocó MTA, en otra cemento Portland y en la tercena ninguna pasta. Se procedió al sacrificio de los grupos experimentales a la 1era, 2da, 3era y 4ta semana respectiva y se evaluó las muestras obtenidas de las áreas quirúrgicas mediante conteo de osteocitos y osteoblastos. Resultados: Tanto el MTA como el cemento Portland poseen la misma capacidad osteoinductiva en la 1era, 2da y 3era semana (p>0,05). Sin embargo, en la 4ta semana el MTA tuvo mayor capacidad osteoinductora al estimular mayor número de osteoblastos que el cemento Portland (p=0,024). Conclusiones: El MTA y el cemento Portland tipo I mostraron similar efecto osteoinductor durante las 3 primeras semanas de evaluación. El MTA demostró mayor efecto osteoinductor durante la cuarta semana de valoración.

Introduction: An experimental study was carried out to determine the osteoinductive effect of Mineral Trioxide Aggregate (MTA) versus Portland Cement type I on mandibular bone lesions. Methodology: Twelve 3-month-old male New Zealand rabbits were divided into 4 equal groups. All rabbits were anesthetized using Pentobarbital. An incision of the mandibular skin was performed to expose the bone on which 3 cavities of 2mm each one were made. In one cavity MTA was placed, in another Portland Cement type I and the third remained empty. The experimental groups were sacrificed at the 1st, 2nd, 3rd and 4th respective weeks and evaluated histologically by counting osteocytes and osteoblasts. Results: Both MTA and Portland cement have the same osteoinductive capacity in the 1st, 2nd and 3rd week (0.05

Rat subcutaneous tissue response to calcium silicate containing different arsenic concentrations

Objective: To evaluate the response of rat subcutaneous tissue in implanted polyethylene tubes that were filled with GMTA Angelus and Portland cements containing different arsenic concentrations. Material and Methods: Atomic absorption spectrophotometry was utilized to obtain the values of the arsenic concentration in the materials. Thirty-six rats were divided into 3 groups of 12 animals for each experimental period. Each animal received two implants of polyethylene tubes filled with different test cements and the lateral of the tubes was used as a control group. After 15, 30 and 60 days of implantation, the animals were killed and the specimens were prepared for descriptive and morphometric analysis considering: inflammatory cells, collagen fibers, fibroblasts, blood vessels and other components. The results were analyzed utilizing the Kuskal-Wallis test and the Dunn's Multiple test for comparison (p<0.05). Results: The materials showed, according to atomic absorption spectrophotometry, the following doses of arsenic: GMTA Angelus: 5.01 mg/kg, WPC Irajazinho: 0.69 mg/kg, GPC Minetti: 18.46 mg/kg and GPC Votoran: 10.76 mg/kg. In a 60-day periods, all specimens displayed a neoformation of connective tissue with a structure of fibrocellular aspect (capsule). Control groups and MTA Angelus produced the lower amount of inflammatory reaction and GPC Minetti, the highest reaction. Conclusions: There was no direct relationship between the concentration of arsenic present in the composition of the materials and the intensity of the inflammatory reactions. Higher values, as 18.46 mg/kg of arsenic in the cement, produce characteristics of severe inflammation reaction at the 60-day period. The best results were found in MTA angelus. .

Similitud de la morfología y química elemental de los cementos tipo agregado de trióxido mineral y cemento Portland, mediante microscopia electrónica de barrido y espectroscopia de dispersión de electrones / Similarities of elemental chemistry and morphology of cements type mineral trioxide aggregate and Portland cement through the use of scanning electronic microscopy and electron dispersion spectroscopy

En la actualidad, los estudios acerca de la similitud entre el cemento Portland y los cementos tipo mineral de tri-oxi agregado han demostrado que estos compuestos presentan un desempeño análogo, ya que son elaborados con base en el cemento Portland. Con el objeto de verificar los componentes y porcentajes del cemento Portland y los cementos comerciales tipo agregado de trióxido mineral Pro-Root® blanco y Pro-Root® gris, Angelus® y CPM® se elaboraron cinco muestras de cada material de 8 x 4 mm y se les practicó un estudio de textura de superficie mediante microscopio electrónico de barrido y un análisis de espectrometría de energía dispersiva. Resultados: Los cementos mostraron gran similitud entre el cemento Portland y el agregado de trióxido mineral, sólo que en el agregado de trióxido mineral encontramos ausencia de Fe, Mg, Na y K, y en los cementos tipo agregado de trióxido mineral se encontró regularmente O, C, Si, Ca, Al, Cl y Bi; únicamente se detectó la presencia de Ba en el CPM®. Conclusiones: Encontramos gran similitud de los componentes químicos entre el cemento Portland y los cementos tipo agregado de trióxido mineral de todas las marcas comerciales.

Currently, studies on similarities among Portland cement and cements type mineral trioxide aggregate have shown that these compounds exhibit similar performance. This can be due to the fact that they are made based on Portland cement. With the aim of assessing percentages and components of Portland cement and commercial cements type mineral trioxide aggregate ProRoot® white and Pro-Root® grey, Angelus® and CPM®, five 8 x 4 mm samples of each material were processed. These samples were subjected to a study of surface texture. This study was conducted with the help of a scanning electron microscope as well as a energy dispersive spectrometry analysis. Results: Upon comparison, Portland cement and mineral trioxide aggregate cements showed great similarities. The main difference was than in mineral trioxide aggregate there was absence of Fe, Mg, Na and K; in mineral trioxide aggregate cements O, C, Si, Ca, Al, Cl and Bi were found regularly. Ba presence was only detected in CP®. Conclusions: The present study established the presence of great similarities among chemical components of Portland cement and mineral trioxide aggregate cements of all commercial brands.

A comparative evaluation of compressive strength of Portland cement with zinc oxide eugenol and Polymer-reinforced cement: An in vitro analysis.

Objective: The purpose of this study is to evaluate the ultimate compressive strength of 50% and 25% Portland cement mixed with Polymer-reinforced zinc oxide eugenol and zinc oxide eugenol cement after 1 hour, 24 hours, and 7 days. Materials and Methods: One hundred and eighty samples were selected. The samples were made cylindrical of size 6 × 8 mm and were divided into six groups as follows with each group consisting of 10 samples. Group 1: Polymer-reinforced zinc oxide eugenol with 50% Portland cement (PMZNPC 50%) Group 2: Polymer-reinforced zinc oxide eugenol with 25% Portland cement (PMZNPC 25%) Group 3: Polymer-reinforced zinc oxide eugenol with 0% Portland cement (PMZNPC 0%) Group 4: Zinc oxide eugenol with 50% Portland cement (ZNPC 50%) Group 5: Zinc oxide eugenol with 25% Portland cement (ZNPC 25%) Group 6: Zinc oxide eugenol with 0% Portland cement (ZNPC 0%) These samples were further subdivided based on time interval and were tested at 1 hour, 24 hours and at 7 th day. After each period of time all the specimens were tested by vertical CVR loaded frame with capacity of 5 tones/0473-10kan National Physical laboratory, New Delhi and the results were statistically analyzed using ANOVA and Scheffe test. Results: Polymer-reinforced cement with 50% Portland cement, Zinc oxide with 50% Portland cement, Polymer-reinforced cement with 25% Portland cement and Zinc oxide with 25% Portland cement exhibited higher compressive strength when compared to Zinc oxide with 0% Portland cement and Polymer-reinforced cement with 0% Portland cement, at different periods of time. The difference between these two groups were statistically significant (P < 0.05) and it is suggested that mixture of 50% and 25% Portland cement in Zinc oxide eugenol and Polymer-modified zinc oxide cement can be used as core build up material and permanent filling material. Conclusion: It is concluded that 50% and 25% Portland cement in zinc oxide eugenol and polymer-modified zinc oxide eugenol results in higher compressive strength and hence can be used as permanent filling material and core built-up material. Keywords: Compressive strength, Portland cement, Polymer-reinforced cement, eugenol

Avaliação das atividades antimicrobiana e biológica do cimento portland associado ao AH PLUS em diferentes proporções / Evaluation of antimicrobial and biological activities of Portland cement associated of AH Plus sealer in different proportions

A endodontia vem sofrendo um processo de evolução muito grande nos últimos anos. Apesar dessa grande evolução técnico-científica, infelizmente o tratamento endodôntico convencional ainda não possibilita a obtenção do sucesso total. Objetivo: O objetivo do presente estudo foi avaliar a atividade antimicrobiana e a resposta do tecido subcutâneo de ratos frente à implantação do cimento Portland associado ao AH Plus em diferentes proporções. Metodologia: Para a avaliação da resposta biológica, foram utilizados 42 ratos (Rattus Norvegicus), que foram divididos em 14 animais para cada período experimental. Para se avaliar a atividade antimicrobiana, foi utilizada a técnica de difusão radial em placas de ágar Mueller-Hinton. Foram utilizadas 30 linhagens de campo e 1 ATCC (29212) de Enterococcus faecalis. Os materiais foram proporcionados em massa e os poços preenchidos com os cimentos através de seringas tipo Luer-Look. Com os dados em mãos, os mesmos foram submetidos à análise estatística, empregando-se o teste Kruskal-Wallis para comparação global e o teste de Miller para as comparações individuais com nível de significância de 5 por cento. Resultados: Quanto à resposta biológica, todos os grupos apresentaram bom comportamento. Em relação a atividade antimicrobiana, os grupos 4, 5 e 6 apresentaram atividade, tanto em 24, quanto em 48 horas, com diferença estatisticamente significante com relação aos outros grupos. Conclusão: Conclui-se que a associação do AH Plus ao cimento Portland apresenta boa resposta tecidual e atividade antimicrobiana, principalmente nos grupo com maior quantidade de cimento AH Plus...

Endodontics has been suffering a long evolution process in recent years. Despite this great technical and scientific developments, unfortunately the conventional endodontic treatment hasn't allows obtaining the total success. Objective: the objective of the present study was to evaluate the antimicrobial activity and the response of the subcutaneous tissue against deployment of associated Portland cement to AH Plus sealer in different proportions. Methodology: for evaluation of biological response, 42 rats were used (Rattus Norvegicus), which were divided into 14 animals for each experimental period. To evaluate antimicrobial activity, was used the technique of radial diffusion in Mueller-Hinton agar plates. 30 strains were used and 1 ATCC (29212) of Enterococcus faecalis. The materials were provided by weight and pits filled with the cements through syringes Luer-type Look. With data, they were subjected to statistical analysis, using the Kruskal-Wallis test for global comparison and the Miller test for individual comparisons with a significance level of 5. Results: as for biological response, all groups showed good behavior. In relation to antimicrobial activity, groups 4, 5 and 6 showed activity in both. 24, 48 hours, with statistically significant difference with respect to other groups. Conclusion: It is concluded that the Association of AH Plus to Portland cement and tissue response presents good antimicrobial activity, mainly in the group with the highest amount of cement AH Plus...

Propriedades físico-químicas e biológicas de cimento experimental à base de Portland associado a diferentes radiopacificadores / Physical, chemical and biological properties of an experimental Portland-based cement with different radiopacifier agents

O objetivo do estudo foi avaliar as propriedades físicas, químicas e biológicas de um cimento experimental à base de Portland contendo diferentes agentes radiopacificadores. Os cimentos foram divididos em 6 grupos: 1. MTA-Angelus branco (controle), 2. cimento Portland branco (CP), 3. CP com 20% de óxido de zircônio (OZ), 4. CP/50% OZ, 5. CP com 20% de tungstato de cálcio (TC) e 6. CP/50% TC. As proporções foram determinadas em peso (80 e 50% de CP para 20 e 50% de radiopacificadores, respectivamente). Os cimentos experimentais foram manipulados utilizando 0,3 mL de líquido composto por 80% de água destilada e 20% de propilenoglicol, em volume. A caracterização dos materiais foi realizada em microscopia eletrônica de varredura (MEV), no modo EDS e em difratômetro de raios-X (XRD). Para os testes de radiopacidade, escoamento, espessura de filme e solubilidade foram seguidas as especificações no 57 da ANSI/ADA (2000). Na determinação do tempo de presa, foi empregada a norma ASTM C266/2008. Na análise do pH e liberação de íons cálcio foram analisados os períodos de 3, 24, 72 e 168 horas. Para análise da descoloração dentária, foram realizadas análises em espectrofotômetro, estereomicroscopia e MEV. Para análise da resposta inflamatória, foi utilizado o teste de implantação em subcutâneo de ratos. A utilização do óxido de zircônio e do tungstato de cálcio em combinação com o cimento Portland resultou no desenvolvimento de cimentos que exibiram uma radiopacidade próxima (20% de radiopacificadores) ou acima (50%) do recomendado pela norma no 57 da ANSI/ADA; tempo de presa mais prolongado, espessura de filme menor e escoamento mais elevado em comparação com o MTA-Angelus; solubilidade adequada e comparável ao MTA-Angelus, elevado pH e liberação de íons cálcio superior ao MTA-Angelus nos períodos iniciais e similar aos 7 dias, ausência de descoloração dentária e resposta inflamatória semelhante ao MTA-Angelus...

The aim of the study was to evaluate the physical, chemical and biological properties of an experimental calcium silicate-based cement with different concentrations of the radiopacifiers zirconium oxide and calcium tungstate. The materials were divided in 6 groups: 1. White MTA (control), 2. White Portland cement (PC), 3. PC with 20% zirconium oxide (ZO), 4. PC/50% ZO, 5. PC with 20% calcium tungstate (CT) and 6. PC/50% CT. The proportions were determined by weight. The cements were manipulated using 0.3 mL of liquid composed of 80% distilled water and 20% propylene glycol. The control was manipulated according to manufacturers instructions. The characterization of the materials was performed using scanning electron microscopy (SEM) in EDS mode and X-ray diffractometrer (XRD). For radiopacity, flowability, film thickness and solubility test, the specifications no 57 of ADA (2000) was followed. To determine the setting time, ASTM C266/2008 specifications was followed. For pH and calcium ion release assessment, the periods of 3, 24, 72 and 168 hours were evaluated. The analysis of dental discolouration was performed using spectrophotometer, stereomicroscopy and SEM. To evaluate the inflammatory response, the test of subcutaneous implantation in rats was used. The use of zirconium oxide and calcium tungstate in association with Portland cement resulted in development of cements with radiopacity nearly (20% radiopacifiers) or above (50%) the recommended by ANSI/ADA specifications n a 57, more prolonged setting time, lower film thickness and higher flowability in comparison with MTAAngelus, an adequate and comparable solubility with MTA-Angelus, high pH and calcium ion release higher than MTA-Angelus in the initial periods and similar at 7 days, absence of dental discolouration and inflammatory response similar to that presented by MTA-Angelus...

In vivo evaluation of tissue response to new endodontic sealers

Introduction: The sealers can be in direct contact with the periapical tissues. Thus, these materials must have appropriate physical and biological properties, providing conditions for repair to occur. Objective: The aim of this study was to evaluate the response of rat subcutaneous tissue to endodontics sealers. Material and methods: Three materials comprised the groups: group I - Zinc Oxide, Eugenol and Iodoform paste, group II - Portland cement with propylene glycol, and group III - MTA Fillapex® (Angelus). These materials were placed in polyethylene tubes and implanted into dorsal connective tissue of Wistar rats for seven and 15 days. The specimens were stained with hematoxylin and eosin and evaluated regarding to inflammatory reaction parameters through a light microscope. The data were compared using Kruskal-Wallis test with significance level of 5%. The intensity of inflammatory response against the sealers was analyzed by two blinded and previously calibrated observers for all experimental periods. Results: The histological evaluation showed that all the materials caused a moderated inflammatory reaction at seven days which decreased with time. A greater inflammatory reaction was observed at seven days in group I. The other specimens had significantly less inflammatory cells when compared to this group. Tubes with MTA Fillapex® presented some giant cells, macrophages and lymphocytes after seven days. At 15 days, the presence of fibroblasts and collagen fibers was observed indicating normal tissue healing. The group II showed similar results to those observed in MTA Fillapex® already at seven days. At 15 days the inflammatory reaction presented was almost absent at the tissue, with many collagen fibers indicating normal tissue healing. Statistical analysis showed a significant statistical difference amongst the group I (seven days) and II (15 days) (p < 0.05). In the other groups no significant statistical differences were observed. Conclusion: MTA Fillapex® and Portland cement with propylene glycol were more biocompatible than the other tested cements.

Análisis de la composición química de los cementos tipo MTA y PORTLAND tipo I / Comparative chemical analysis of MTA and PORTLAND i cements

El propósito de este estudio es evaluar la composición química de tres cementos: Portland tipo I (CEMEX Samper , Cundinamarca, Colombia), Portland tipo I (CEMEX-Diamante, Ibagué, Colombia) y ProRoot MTA (Dentsply-Maillefer, Ballaigues, Suiza). Se utilizó una muestra probabilística de 17 pastillas para cada tipo de cemento. El análisis se llevó a cabo con la microsonda EDAX (Mahwah, NJ, USA) del microscopio de barrido electrónico SEM FEI (Quanta 200, Hillsboro, Oregon USA), bajo condiciones estandarizadas de lectura de las muestras. Se hicieron cuatro lecturas por muestra, para un subtotal de 68 lecturas por cada tipo de cemento y un total de 208 lecturas. Los resultados se obtuvieron en porcentaje de peso sólido por elemento. Los datos generales fueron analizados por las pruebas ANOVA, comparaciones múltiples de Tukey y t de Student. Se observaron tres elementos comunes entre los tres cementos: Ca, Si y Al, pero se encontraron diferencias estadísticamente significativas de los elementos comunes entre el cemento ProRoot MTA y los cementos Portland I. El Bi solo se encontró en el ProRoot MTA y el S solo se encontró en los cementos Portland tipo I. Se concluye que la composición de los tres cementos es similar. Sin embargo, es necesario evaluar el impacto que puede tener, tanto la presencia de S en los cementos Portland I, como la diferencia de concentraciones de los elementos que fueron comunes en los tres cementos en cuanto a biocompatibilidad y efectividad clínica.

The objective of this study is to evaluate the chemical composition of three cements: Portland Type I (CEMEXSamper , Cundinamarca, Colombia), Portland Type I (CEMEX-Diamante, Ibague, Colombia) and Pro Root MTA (Dentsply-Maillefer, Ballaigues, Switzerland). A probabilistic sample of 17 tablets for each type of cement was used. The analysis was carried out with energy dispersive analysis with x-rays (EDAX) (Mahwah, NJ, USA) in the scanning electron microscope (SEM) FEI (Quanta 200, Hillsboro, Oregon, USA) under standard sample reading conditions. Four readings per sample were carried out for a total of 68 readings per cement, and a grand total of 208 readings. The results were obtained as a percentage of solid weight per element. General data was analyzed with the ANOVA test, and Tukey and t of Student multiple comparison tests. Three common elements were observed between the three cements: Ca, Si, and Al, but there were significant statistical differences between the common elements of the ProRoot MTA and the Portland cements I. The Bi was found only in the ProRoot MTA, and the S only in the Portland type I cements. It can be concluded then that the composition of the three cements is similar; however, it is necessary to evaluate the impact that the presence of S in the Portland I cements as well as the difference in concentrations of the three common elements may have in the biocompatibility and clinical effectiveness.

Estudo clínico, radiográfico, histológico e imuno-histoquímico na resposta pulpar após o uso de diferentes materiais capeadores em pulpotomias de dentes decíduos humanos / Clinical, radiographic, histological, and immunohistochemistry study on pulpal response after the use of different pulp capping materials in pulpotomies of human primary teeth

O objetivo deste estudo foi avaliar: 1) a resposta pulpar de dentes decíduos humanos após pulpotomia com diferentes materiais capeadores por meio de análise clínica, radiográfica e histológica; e 2) a expressão da Proteína 1 da Matriz Dentinária (DMP-1) na resposta pulpar. Vinte e cinco molares decíduos inferiores de 22 crianças com idade entre 6 e 9 anos foram criteriosamente selecionados. Os dentes foram randomicamente divididos nos grupos Formocresol de Buckley diluído a 1/5 (Grupo I - FC), Hidróxido de Cálcio (Grupo II HC), Agregado Trióxido Mineral (Grupo III MTA), Otosporin® + Hidróxido de Cálcio (Grupo IV OTO+HC) e Cimento Portland (Grupo V PC), e tratados pela técnica convencional de pulpotomia em sessão única. As avaliações clínicas e radiográficas foram realizadas até o período normal de esfoliação. Os dentes foram extraídos e processados para análise histológica e imuno-histoquímica. Os resultados clínicos e radiográficos não mostraram diferença estatisticamente significativa nos grupos estudados (p>0,05). A análise estatística da avaliação histológica revelou diferença estatisticamente significativa para presença de barreira dentinária e camada odontoblástica entre o Grupo I(FC) e os Grupos II(HC), III(MTA), IV(OTO+HC) e V(PC) visto que o Grupo I(FC) não apresentou barreira dentinária e camada odontoblástica em nenhuma das lâminas observadas. Não houve diferença estatisticamente significativa entre os grupos estudados quando da avaliação da calcificação pulpar. Para o item reabsorção interna observou-se diferença estatisticamente significativa entre o Grupo I(FC), II(HC) e os Grupos III(MTA), IV(OTO+HC) e V(PC) onde não se observaram reabsorções internas nas análises histológicas. A análise da expressão da DMP-1 demonstrou para o Grupo I(FC) imunomarcação localizada na região de calcificações pulpares localizadas nas raízes dos dentes avaliados, não havendo camada odontoblástica nem formação de barreira dentinária. Os Grupos II(HC), III...

The aim of this study was to evaluate: 1) the pulpal response of human primary teeth after pulpotomies with different pulp capping materials through clinical, radiographic and histological analysis; and 2) the expression of Dentin Matrix Protein 1 (DMP-1) in the pulpal response. Twenty-five primary molars of 22 children aged 6-9 years-old were criteriously selected. The teeth were randomly divided into the following groups: Buckleys Formocresol (diluted 1:5) (Group I - FC), Calcium Hydroxide - (Group II CH), Mineral Trioxide Aggregate (Group III MTA), Otosporin® + Calcium Hydroxide (Group IV OTO+CH) and Portland cement (Group V PC); and treated by the conventional technique of pulpotomy at a single appointment. The clinical and radiographic evaluations were performed until the teeth underwent normal exfoliation. The teeth were extracted and processed for histological and immunohistochemical analyses. The clinical and radiographic studies did not show statistically significant difference among the groups studied (p>0.05). The statistical analysis of the histological evaluation revealed statistically significant difference relating to the presence of the dentine barrier and odontoblastic layer between Group I(FC) and Groups II(CH), III(MTA), IV(OTO+CH) and V(PC) since the Group I(FC) did not exhibited dentine barrier and odontoblastic layer in any of the cuts observed. There was no statistically significant difference among the groups studied regarding to the evaluation of pulpal calcification. Concerning to internal resorption, there was a statistically significant difference among Group I(FC), II(CH) and Groups III(MTA), IV(OTO+CH) and V(PC) where internal resorption was not seen in the histological analyses. The analysis of the expression DMP-1 demonstrated for Group I(FC) immunostaining located in the area of pulpal calcifications within the roots of the teeth evaluated; however, neither odontoblastic layer nor dentine barrier were seen...

Estudo clínico, radiográfico, histológico e imuno-histoquímico na resposta pulpar após o uso de diferentes materiais capeadores em pulpotomias de dentes decíduos humanos / Clinical, radiographic, histological, and immunohistochemistry study on pulpal response after the use of different pulp capping materials in pulpotomies of human primary teeth

O objetivo deste estudo foi avaliar: 1) a resposta pulpar de dentes decíduos humanos após pulpotomia com diferentes materiais capeadores por meio de análise clínica, radiográfica e histológica; e 2) a expressão da Proteína 1 da Matriz Dentinária (DMP-1) na resposta pulpar. Vinte e cinco molares decíduos inferiores de 22 crianças com idade entre 6 e 9 anos foram criteriosamente selecionados. Os dentes foram randomicamente divididos nos grupos Formocresol de Buckley diluído a 1/5 (Grupo I - FC), Hidróxido de Cálcio (Grupo II HC), Agregado Trióxido Mineral (Grupo III MTA), Otosporin® + Hidróxido de Cálcio (Grupo IV OTO+HC) e Cimento Portland (Grupo V PC), e tratados pela técnica convencional de pulpotomia em sessão única. As avaliações clínicas e radiográficas foram realizadas até o período normal de esfoliação. Os dentes foram extraídos e processados para análise histológica e imuno-histoquímica. Os resultados clínicos e radiográficos não mostraram diferença estatisticamente significativa nos grupos estudados (p>0,05). A análise estatística da avaliação histológica revelou diferença estatisticamente significativa para presença de barreira dentinária e camada odontoblástica entre o Grupo I(FC) e os Grupos II(HC), III(MTA), IV(OTO+HC) e V(PC) visto que o Grupo I(FC) não apresentou barreira dentinária e camada odontoblástica em nenhuma das lâminas observadas. Não houve diferença estatisticamente significativa entre os grupos estudados quando da avaliação da calcificação pulpar. Para o item reabsorção interna observou-se diferença estatisticamente significativa entre o Grupo I(FC), II(HC) e os Grupos III(MTA), IV(OTO+HC) e V(PC) onde não se observaram reabsorções internas nas análises histológicas. A análise da expressão da DMP-1 demonstrou para o Grupo I(FC) imunomarcação localizada na região de calcificações pulpares localizadas nas raízes dos dentes avaliados, não havendo camada odontoblástica nem formação de barreira dentinária. Os Grupos II(HC), III...

The aim of this study was to evaluate: 1) the pulpal response of human primary teeth after pulpotomies with different pulp capping materials through clinical, radiographic and histological analysis; and 2) the expression of Dentin Matrix Protein 1 (DMP-1) in the pulpal response. Twenty-five primary molars of 22 children aged 6-9 years-old were criteriously selected. The teeth were randomly divided into the following groups: Buckleys Formocresol (diluted 1:5) (Group I - FC), Calcium Hydroxide - (Group II CH), Mineral Trioxide Aggregate (Group III MTA), Otosporin® + Calcium Hydroxide (Group IV OTO+CH) and Portland cement (Group V PC); and treated by the conventional technique of pulpotomy at a single appointment. The clinical and radiographic evaluations were performed until the teeth underwent normal exfoliation. The teeth were extracted and processed for histological and immunohistochemical analyses. The clinical and radiographic studies did not show statistically significant difference among the groups studied (p>0.05). The statistical analysis of the histological evaluation revealed statistically significant difference relating to the presence of the dentine barrier and odontoblastic layer between Group I(FC) and Groups II(CH), III(MTA), IV(OTO+CH) and V(PC) since the Group I(FC) did not exhibited dentine barrier and odontoblastic layer in any of the cuts observed. There was no statistically significant difference among the groups studied regarding to the evaluation of pulpal calcification. Concerning to internal resorption, there was a statistically significant difference among Group I(FC), II(CH) and Groups III(MTA), IV(OTO+CH) and V(PC) where internal resorption was not seen in the histological analyses. The analysis of the expression DMP-1 demonstrated for Group I(FC) immunostaining located in the area of pulpal calcifications within the roots of the teeth evaluated; however, neither odontoblastic layer nor dentine barrier were seen...

Rat subcutaneous tissue response to MTA Fillapex® and Portland cement

The aim of this study was to evaluate the response of rat subcutaneous tissue to MTA Fillapex® (Angelus), an experimental root canal filling material based on Portland cement and propylene glycol (PCPG), and a zinc oxide, eugenol and iodoform (ZOEI) paste. These materials were placed in polyethylene tubes and implanted into the dorsal connective tissue of Wistar rats for 7 and 15 days. The specimens were stained with hematoxylin and eosin, and evaluated regarding inflammatory reaction parameters by optical microscopy. The intensity of inflammatory response against the sealers was analyzed by two blinded and previously calibrated examiners for all experimental periods (kappa=0.96). The histological evaluation showed that all materials caused a moderate inflammatory reaction at 7 days, which subsided with time. A greater inflammatory reaction was observed at 7 days in the tubes filled with ZOEI paste. Tubes filled with MTA Fillapex presented some giant cells, macrophages and lymphocytes after 7 days. At 15 days, the presence of fibroblasts and collagen fibers was observed indicating normal tissue healing. The tubes filled with PCPG showed similar results to those observed in MTA Fillapex. At 15 days, the inflammatory reaction was almost absent at the tissue, with several collagen fibers indicating normal tissue healing. Data were analyzed by the nonparametric Kruskal-Wallis test (α=0.05). Statistically significant difference (p<0.05) was found only between PCPG at 15 days and ZOEI at 7 days groups. No significant differences were observed among the other groups/periods (p>0.05). MTA Fillapex and Portland cement added with propylene glycol had greater tissue compatibility than the PCPG paste.

O objetivo deste estudo foi avaliar a resposta do tecido subcutâneo de rato ao MTA Fillapex® (Angelus), a um cimento endodôntico experimental à base de cimento Portland e propilenoglicol, e à pasta de óxido de zinco e eugenol com iodofórmio. Estes materiais foram colocados em tubos de polietileno e implantados no tecido conjuntivo do dorso de ratos Wistar, por 7 e 15 dias. Os espécimes foram corados com hematoxilina e eosina e os parâmetros de reação inflamatória foram avaliados em microscópio óptico. A intensidade da resposta inflamatória provocada pelos cimentos foi analisada em todos os períodos por dois observadores previamente calibrados (kappa 0,96) e sem conhecimento dos grupos experimentais. O exame histológico mostrou que todos os materiais provocaram reação inflamatória moderada aos 7 dias que regrediu com o tempo. A maior resposta inflamatória do tecido foi observada aos 7 dias, nos tubos preenchidos com pasta de Óxido de Zinco e Eugenol com Iodofórmio. Os tubos com MTA Fillapex apresentaram algumas células gigantes, macrófagos e linfócitos após 7 dias. Aos 15 dias, a presença de fibroblastos e fibras de colágenas foi observada, indicando processo de cicatrização do tecido. Os tubos com o cimento Portland mostraram resultados semelhantes aos observados no grupo MTA Fillapex. Aos 15 dias, a reação inflamatória apresentada foi praticamente ausente, com muitas fibras colágenas, indicando cicatrização normal do tecido. A análise estatística mostrou diferença estatisticamente significante entre o grupo de cimento Portland (15 dias) e óxido de zinco eugenol com Iodofórmio (7 dias) (p<0,05). Nos outros grupos não houve diferença estatística significante. MTA Fillapex e cimento Portland são mais biocompatíveis do que os outros cimentos testados.

Influence of radiopacifying agents on the solubility, pH and antimicrobial activity of portland cement

The aim of this study was to evaluate the interference of the radiopacifiers bismuth oxide (BO), bismuth carbonate (BC), bismuth subnitrate (BS), and zirconiun oxide (ZO) on the solubility, alkalinity and antimicrobial properties of white Portland cement (WPC). The substances were incorporated to PC, at a ratio of 1:4 (v/v) and subjected to a solubility test. To evaluate the pH, the cements were inserted into retrograde cavities prepared in simulated acrylic teeth and immediately immersed in deionized water. The pH of the solution was measured at 3, 24, 72 and 168 h. The antimicrobial activity was evaluated by a radial diffusion method against the microorganisms S. aureus (ATCC 25923), P. aeruginosa (ATCC 27853), E. faecalis (ATCC 29212) and C. albicans (ATCC 10231). The zone of microbial growth inhibition was measured after 24 h. The addition of BS and BC increased the solubility of the cement. The pH values demonstrated that all materials produced alkaline levels. At 3 h, BS showed lower pH than WPC (p<0.05). At 168 h, all materials showed similar pHs (p>0.05). The materials did not present antimicrobial activity for S. aureus, P. aeruginosas and E. faecalis (p>0.05). With regards to C. albicans, all materials formed an inhibition zone, mainly the mixture of WPC with ZO (p<0.05). The type of radiopacifier incorporated into WPC interfered with its physical and antimicrobial properties. ZO was found to be a viable radiopacifier that can be used with WPC.

Characterization of calcium oxide in root perforation sealer materials

Root perforation represents an undesirable complication that may lead to an unfavorable prognosis. The aims of this study were to characterize and to compare the presence of calcium oxide (CaO) on the chemical composition of materials used for root perforation therapy: gray and white mineral trioxide aggregate (MTA) and Portland cement (PC), gray MTA+5%CaO and gray MTA+10%CaO. The last two materials were analyzed to evaluate the increase of CaO in the final sample. CaO alone was used as a standard. Eighteen polyethylene tubes with an internal diameter of 3 mm and 3 mm in length were prepared, filled and then transferred to a chamber with 95% relative humidity and a temperature of 37ºC. The chemical compounds (particularly CaO) and the main components were analyzed by energy-dispersive X-ray microanalysis (EDX). EDX revealed the following concentrations of CaO: gray MTA: 59.28%, white MTA: 63.09%; PC: 72.51%; gray MTA+5%CaO: 63.48% and gray MTA+10%CaO: 67.55%. The tested materials presented different concentrations of CaO. Even with an increase of 5 and 10% CaO in gray MTA, the CaO levels found in the MTA samples were lower than those found in PC.

A perfuração do canal radicular representa uma complicação indesejável que sugere um prognóstico desfavorável. Os objetivos deste estudo foram caracterizar e comparar a presença de óxido de cálcio (CaO) na composição química de vários materiais utilizados no tratamento de perfurações radiculares. Foram analisados os materiais MTA cinza e branco, cimento Portland e na tentativa de se observar o aumento nos valores de CaO foram testados MTA cinza+5% de óxido de cálcio, MTA cinza+10% de óxido de cálcio e o CaO (padrão). Foram preparados 18 tubos de polietileno com diâmetro interno e comprimento de 3 mm. Estes foram preenchidos e depois transferidos para uma estufa com umidade relativa de 95% e temperatura de 37°C. Os compostos químicos (principalmente o óxido de cálcio) e os principais componentes foram avaliados por espectrometria de dispersão de raios-X (EDX). A análise por EDX revelou as seguintes concentrações de CaO: 59,28% no MTA cinza; 63,09% no MTA branco; 72,51% no cimento Portland; 63,48% no MTA cinza+5% de CaO; 67,55% no MTA cinza+10% de CaO. Os materiais testados apresentaram diferentes concentrações de CaO. Mesmo com o acréscimo de CaO nas concentrações de 5 e 10% ao MTA cinza, os valores de CaO foram inferiores aos observados no cimento Portland.

The use of Portland cement in the repair of mandibular fractures in rats / Uso de cimento Portland no reparo de fratura mandibular em ratos

PURPOSE: To evaluate the bone healing of mandibular fractures following the use of Portland cement. METHODS: Thirty-two male Wistar rats were divided into control and experimental groups. In the control group the rats were submitted to a mandibular fracture, which was reduced, and the soft tissues were sutured. In the experimental group the rats had the mandibular fracture reduced and maintained with the Portland cement. The animals were euthanized 7 and 21 days after surgery by injecting a lethal dose of anesthetic. The following variables were studied: weight of the animals, radiographic images, histopathological features and time of surgery. RESULTS: A weight loss was observed in the specimens of both groups at the different times of evaluation, a greater difference in weight before and after surgery being found in the experimental group, which was statistically significant (p <0.05, p = 0.041). From the histological point of view, with a margin of error (5.0 percent) the only two significant differences (p <0.05) recorded in the variables were "Material deployed" and "Bone resorption" during the evaluations at 7 and 21 days, respectively. CONCLUSION: The Portland cement served to promote bone healing.

OBJETIVO: Avaliar a reparação óssea de fratura mandibular após o uso do cimento Portland (CP). MÉTODOS: Trinta e dois ratos machos Wistar foram divididos em grupo controle e grupo experimental. No grupo controle os ratos foram submetidos à fratura, redução e manutenção dos seguimentos com sutura dos tecidos moles. No grupo experimental foram submetidos a fratura, redução e manutenção dos segmentos fraturados com CP e sutura dos tecidos. Os animais foram eutanasiados com sete e 21 dias de pós-operatório através da injeção de dose letal dos anestésicos adotados. As variáveis estudadas foram: peso dos animais, avaliação tomográfica, avaliação histológica e tempo cirúrgico. RESULTADOS: Perda de peso foi observada nos espécimes de ambos os grupos nos diferentes intervalos de tempo considerados, sendo maior a diferença de peso antes e após cirurgia para o grupo experimental, que foi estatisticamente significante (p<0,05; p=0,041). Do ponto de vista histológico para a margem de erro fixada (5,0 por cento) as duas únicas diferenças significativas (p<0,05) foram registradas nas variáveis: "Material implantado" na avaliação com sete dias e "Reabsorção óssea" na avaliação com 21 dias. CONCLUSÃO: O cimento Portland atuou promovendo a reparação óssea.