Avaliação de propriedades físico-químicas, mecânicas e antimicrobianos do MTA e cimento Portland associado a solução de nanopartículas de prata

Pós-graduação em Odontologia - FOAR

Resposta tecidual induzida por Biodentine™e MTA Branco em subcutâneo de ratos

Pós-graduação em Odontologia - FOAR

MTA e hidróxido de cálcio como materiais obturadores de canal radicular em reimplante tardio de dente de macaco

O tratamento endodôntico é uma etapa importante do protocolo de atendimento do reimplante dentário e tem uma relação direta com o aparecimento das reabsorções radiculares, maior causa de perda dos dentes reimplantados. O objetivo do trabalho foi analisar o processo de reparo no reimplante tardio de dente de macaco, utilizando o hidróxido de cálcio (Ca(OH)2) e o MTA como materiais obturadores de canal. Cinco macacos Cebus apella adultos tiveram seus incisivos laterais superiores e inferiores, direito e esquerdo, extraídos e deixados em meio ambiente por 60 minutos. Decorrido esse período, foi realizado o preparo biomecânico dos canais e os dentes foram divididos em dois grupos experimentais: grupo I - canal preenchido com pasta de Ca(OH)2 e grupo II - canal preenchido com MTA (Angelus®). Após o selamento da abertura coronária com ionômero de vidro, o ligamento periodontal foi removido e os dentes imersos em solução de fluoreto de sódio 2%, pH 5,5, por 10 minutos. Em seguida, os alvéolos foram irrigados com soro fisiológico e os dentes reimplantados e contidos por 30 dias com fio de aço e resina composta. A eutanásia dos animais foi realizada 60 dias após o reimplante. Os espécimes de ambos os grupos apresentaram reabsorção por substituição e pontos de anquilose ao longo dos três terços radiculares e ausência de reabsorção inflamatória. Não houve diferença significante entre os dois grupos com relação à reabsorção por substituição, porém a quantidade de anquilose foi significativamente maior no grupo do Ca(OH)2. Baseado nesses resultados conclui-se que o MTA pode ser uma opção clínica viável para a obturação de dentes tardiamente reimplantados que necessitam de um longo período de curativo com hidróxido de cálcio.

Influência da diabetes mellitus na resposta tecidual e na capacidade de mineralização dos cimentos Sealapex, MTA Angelus e MTA Fillapex

Pós-graduação em Ciência Odontólogica - FOA

Hydrogen ion and calcium releasing of MTA Fillapex® and MTA-based formulations

MTA is composed of various metal oxides, calcium oxide and bismuth. It has good biological properties and is indicated in cases of endodontic complications. Several commercial formulations are available and further studies are necessary to evaluate these materials. Objective: To evaluate pH and calcium releasing of MTA Fillapex® compared with gray and white MTA. Material and methods: Gray and white MTA (Angelus) and MTA Fillapex® (Angelus) were manipulated and placed into polyethylene tubes and immersed in distilled water. The pH of these solutions was measured at 24 hours, 7 days and 14 days. Simultaneously, at these same aforementioned periods, these materials' calcium releasing was quantified, through atomic absorption spectrophotometry. The results were submitted to ANOVA, with level of significance at 5%. Results: Concerning to pH, the materials present similar behaviors among each other at 24 hours (p > 0.05). At 7 and 14 days, MTA Fillapex® provided significantly lower pH values than the other materials (p < 0.05). Regarding to calcium releasing, at 24 hours and 7 days, MTA Fillapex® provided lower releasing than the other materials (p < 0.05). After 14 days, differences were found between MTA Fillapex® and gray MTA (p < 0.05). Conclusion: All materials showed alkaline pH and calcium releasing, with significantly lower values for MTA Fillapex® sealer.

Evaluation of the physicochemical properties and push-out bond strength of mta-based root canal cement

Aim: This study investigated the flowability, setting time, pH, calcium release and bond strength of a MTA-based cement (MTA Fillapex®) compared to AH Plus and Sealapex. Materials and methods: For the flowability test, the ISO 6876:2001 specification was utilized and for the setting time test, the ASTM C266-03 specification was utilized. For the pH and calcium release measurements, 10 samples were prepared for each group and analyzed for several different periods. For the push-out test, dentin disks were distributed into three groups, according to the cement utilized and into three subgroups, according to the root third (n = 10). After obturation, the specimens underwent push-out testing. The data were compared statistically using a significance level of 5%. Results: The flowability of all materials was found to be similar (p > 0.05). The setting times were different among the groups tested (MTA Fillapex < Sealapex < AH Plus) (p < 0.05). At days 7 and 28, the MTA Fillapex presented the higher pH values (p < 0.05). At 24 hours and at 14 days, the calcium release of the MTA Fillapex was similar to that of Sealapex (p > 0.05). AH Plus presented the lowest pH and calcium release values (p < 0.05). In all root thirds, the adhesion to the dentin of the MTA Fillapex and Sealapex were significantly lower than that of AH Plus (p < 0.05). Conclusion: MTA Fillapex and Sealapex presented several similar properties and both were found to be different than AH Plus. Clinical significance: This study evaluated the physicochemical and mechanical properties of new MTA-based root canal cement, in order to use this scaler in root canal fillings. MTA Fillapex showed satisfactory properties for clinical use.

Influence of the addition of calcium hydroxide powder on some physical and chemical properties of the sealer MTA fillapex

Objective: This study evaluated the flow, pH and calcium release of MTA Fillapex (G1) or Fillapex plus 10% in weight of calcium hydroxide powder (G2), compared to AH Plus (G3) and Sealapex (G4). Materials and methods:The flow test was performed according to ISO 6876:2001 requirements. The sealers were placed into plastic tubes and immersed in deionized water. After 24 hours, 7, 14 and 28 days, the water of each tube was removed and tested to evaluate the pH values and the level of released calcium. Calcium release values were analyzed statistically by Kruskal Wallis and Dunn tests and pH values analyzed by ANOVA and Tukey tests (? = 5%). Results:G1 presented higher flow among all sealers. The addition of 10% calcium hydroxide into MTA Fillapex reduced the flow (p < 0.05) but, in a level, that is lower than the one recommended for ISO norms. G2 and G4 presented pH values and calcium release higher than G3 (p < 0.05) in all periods. G1 presented pH value higher than G3 (p < 0.05), except in 7 days period (p > 0.05). G4 presented higher pH values than G1 and G2, but the calcium release was similar for all periods (p > 0.05). G3 presented lower calcium release among all groups (p < 0.05). Conclusion: The addition of 10% calcium hydroxide in MTA Fillapex caused reduction in flow and no negative interference in pH and/or calcium release. However, the obtained flow is different from ISO requirements. Clinical relevance: MTA Fillapex presents levels of flow above the ISO norms. The addition of calcium hydroxide is a suggestion for solving this problem, but the impact of these procedures should be carefully evaluated.

In vivo evaluation of the inflammatory response and IL-6 immunoexpression promoted by Biodentine and MTA Angelus

Aim To evaluate the inflammatory process induced by Biodentine and mineral trioxide aggregate (MTA) in rat subcutaneous tissues. Methodology A polyethylene tube filled with Biodentine (n = 20) or MTA (n = 20) was placed into the dorsal subcutaneous of forty male rats; in the control group (CG; n = 20), empty tubes were implanted. After 7, 15, 30 and 60 days, the polyethylene tubes surrounded by connective tissue were fixed and embedded in paraffin. The number of inflammatory cells was estimated in HE-stained sections; numerical density of interleukin-6 (IL-6)-immunolabelled cells was also performed. The differences amongst the groups were analysed statistically by Tukey's test (P ≤ 0.05). Results A high number of inflammatory cells and IL-6-positive cells were observed at 7 days, in all groups; however, in the Biodentine group, the number of inflammatory cells and IL-6-immunolabelled cells was significantly higher (P ≤ 0.05) in comparison with the other groups at 7 and 15 days. In the capsules of animals from all groups, a gradual and significant reduction (P ≤ 0.05) of these parameters was seen over time. At 60 days, the capsules exhibited numerous fibroblasts and bundles of collagen fibres; in addition, the number of IL-6-positive cells was not significantly different amongst Biodentine, MTA and control groups. Conclusions There was a significant regression in the inflammatory reaction in the capsules indicating, therefore, that Biodentine is a biocompatible material.

MTA versus Portland cement: review of literature

Introduction: Both Mineral Trioxide Aggregate (MTA) and Portland cement (PC) have been highlighted because of their favorable biological properties, with extensive applications in Endodontics, including the possibility of using into root canal filling. Objective: This article reviews literature related to MTA and PC comparing their physical, chemical and biological properties, as well as their indications. Literature review: Literature reports studies revealing the similarities between these materials’ properties, including both biocompatibility and bone repair induction. Moreover, there is the need for the development of a root canal sealer based on these materials (MTA and PC). Conclusion: MTA and CP show promissory perspective both in Dentistry and Endodontics.

Compressive strength and setting time of MTA and portland cement associated with different radiopacifying agents

The aim of this study was to evaluate the compressive strength and setting time of MTA and Portland cement (PC) associated with bismuth oxide (BO), zirconium oxide (ZO), calcium tungstate (CT), and strontium carbonate (SC). Methods. For the compressive strength test, specimens were evaluated in an EMIC DL 2000 apparatus at 0.5 mm/min speed. For evaluation of setting time, each material was analyzed using Gilmore-type needles. The statistical analysis was performed with ANOVA and the Tukey tests, at 5% significance. Results. After 24 hours, the highest values were found for PC and PC + ZO. At 21 days, PC + BO showed the lowest compressive strength among all the groups. The initial setting time was greater for PC. The final setting time was greater for PC and PC + CT, and MTA had the lowest among the evaluated materials (< 0.05). Conclusion. The results showed that all radiopacifying agents tested may potentially be used in association with PC to replace BO.

Ability of different methods to fill retrograde cavities with MTA.

The Mineral Trioxide Aggregate (MTA) has excellent biological property. However, its consistency makes it difficult to be inserted into retrograde cavities. Objective:To evaluate the ability of different methods to fill retrograde cavities with MTA. Material and methods: Root canals of thirty single-rooted resin teeth were prepared and filled. After the cut of 3 mm short of apical third, retrograde cavities with 3 mm deep were prepared using an ultrasound device and retrotips (CVD, São José dos Campos, SP, Brazil). The retrograde preparation was evaluate by using an operative microscope (D.F. Vasconcellos, São Paulo, SP, Brazil). The teeth were randomly divided into three groups (n = 10), according to the method: 1) condenser (Trinity, São Paulo, SP, Brazil); 2) MTA applicator (Angelus, Londrina, Brazil) + condenser; 3) condenser associated with ultrasound (CVD, São José dos Campos, SP, Brazil). After the filling of retrograde cavities with white MTA (Angelus, Londrina, Brazil), teeth were radiographed using a digital system (Kodak RVG 6000, Rochester, NY, USA). The images were analyzed by UTHSCSA Image Tool 3.0 software. The percentage of filling was calculated by the proportion between the total area of retrograde cavity and the filled area. The radiographic density mean of each third of retrograde cavity filled with MTA was measured by using the histogram tool of the software. The results were submitted to ANOVA and Tukey tests, with 5% of significance. Results: There was no difference in percentage of filling among the groups (p > 0.05) (approximately 85%). By comparing the thirds, the condenser and MTA applicator groups showed higher density for apical and middle third than cervical third (p < 0.05). The ultrasound group presented similar density among the thirds. Conclusion: The filling ability was similar for the studied methods. Ultrasound promoted better distribution of MTA in retrograde cavity, but did not increase the density of material.

Evaluation of the pH, calcium release and antibacterial activity of MTA Fillapex

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise físico-química do MTA e do cimento Portland associado a quatro diferentes radiopacificadores

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of diabetes mellitus on tissue response to MTA and its ability to stimulate mineralization

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)