Efeito de diferentes irrigantes finais na resistência união de um cimento de silicato de cálcio: estudo in vitro / Effect of different final irrigants on the bond strength of a calcium silicate cement : in vitro study

Objetivo: Este estudo teve como objetivo avaliar a resistência de união do cimento Biodentine® à dentina radicular após a utilização de diferentes irrigantes finais. Método: Vinte dentes humanos extraídos tiveram seu terço médio radicular cortado em fatias que foram submersas em hipoclorito de sódio 2,5% e posteriormente divididas aleatoriamente em 4 grupos experimentais (n=15) conforme o irrigante final utilizado (1) água destilada (controle), (2) QMixTM, (3) ácido cítrico 10%, (4) EDTA 17%. Após a imersão na substância teste as amostras foram preenchidas com o cimento Biodentine e imersas em solução salina tamponada com fosfato (PBS) por um período de 7 dias. O teste de push out foi realizado e os valores de resistência de união em Mpa foram obtidos. Os dados foram analisados pelos testes de Kruskal Wallis e Studend- Newman-Keuls. Resultados: Os piores valores de união foram obtidos após a utilização do EDTA enquanto a água destilada, o QMix e o ácido cítrico apresentaram resultados estatisticamente semelhantes entre si. Conclusão: A remoção da smear layer não resultou em melhora nos resultados de união do cimento Biodentine.(AU)

Objective: This study aimed to evaluate the bond strength of Biodentine® cement to root dentin after the use of different final irrigants. Method: Twenty extracted human teeth had their middle root third cut into slices that were submerged in 2.5% sodium hypochlorite and then randomly divided into 4 experimental groups (n=15) according to the final irrigant used (1) distilled water (control), (2) QMixTM, (3) 10% citric acid, (4) 17% EDTA. After immersion in the test substance the samples were filled with Biodentine cement and immersed in phosphate buffered saline (PBS) for a period of 7 days. The push out test was performed and the bond strength values in MPa were obtained. The data were analyzed by Kruskal Wallis and Studend- Newman-Keuls tests. Results: The worst bond values were obtained after using EDTA while distilled water, QMix and citric acid showed statistically similar results to each other. Conclusion: Removal of the smear layer did not result in improved bonding results of Biodentine cement.(AU)

Root filling quality and bond strength of endodontic sealers to human and bovine dentin / Qualidade da obturação e resistência de união de cimentos endodônticos à dentina humana e bovina

Objetivo: Este estudo teve como objetivo comparar a qualidade da obturação e a resistência de união de dois cimentos endodônticos, AH Plus e Bio-C Sealer, em dentes humanos e bovinos. Métodos: Os canais radiculares de 60 dentes unirradiculares [30 humanos (H) e 30 bovinos (B)] foram preparados e obturados por condensação lateral da guta-percha e AH Plus (grupos AP-H e AP-B) ou Bio-C Sealer (grupos BC-H e BC-B). Seis fatias de 1,5 mm de espessura foram obtidas de cada raiz. Os espécimes foram observados em estereomicroscópio para avaliar a qualidade da obturação, considerando possíveis espaços vazios no material obturador. Posteriormente, as fatias radiculares foram avaliadas em termos de resistência de união por push-out e modo de falha. Os dados foram analisados pelos testes de Mann-Whitney e coeficientes de correlação de Spearman (α=5%). Resultados: A qualidade de obturação fornecida por AP e BC foi semelhante em ambos os substratos de dentina. No entanto, ao comparar dentes humanos e bovinos, os escores de espaços vazios foram maiores nas amostras bovinas, para ambos os cimentos. AP teve maior resistência de união à dentina humana e bovina do que BC. No entanto, não houve diferença significativa na resistência de união entre os substratos dentinários, para ambos os cimentos testados. Além disso, houve uma correlação positiva e moderada entre os valores de resistência de união de dentes humanos e bovinos. O modo de falha misto foi o mais prevalente. Conclusão: AP e BC fornecem qualidade de obturação semelhante, mas o primeiro apresenta maiores valores de resistência de união à dentina humana e bovina. A utilização de dentes bovinos como substitutos de amostras humanas parece ser adequada em estudos relacionados à resistência de união, mas não naqueles que testam a qualidade da obturação endodôntica.(AU)

Objective: This study aimed to compare the filling quality and bond strength of two endodontic sealers, AH Plus and Bio-C Sealer, in human and bovine teeth. Methods: The root canals of 60 [30 human (H) and 30 bovine (B)] single-rooted teeth were prepared and filled by lateral condensation of gutta-percha and AH Plus (groups AP-H and AP-B) or Bio-C Sealer (groups BC-H and BC-B). Six 1.5-mm-thick slices were obtained from each root. The specimens were observed under a stereomicroscope to assess filling quality, considering possible voids within the filling material. Subsequently, root slices were evaluated in terms of push-out bond strength and failure mode. Data were analyzed by Mann-Whitney tests and Spearman correlation coefficients (α=5%). Results: The filling quality provided by AP and BC was similar in both dentin substrates. However, when comparing human and bovine teeth, void scores were greater in the bovine samples, for both sealers. AP had higher bond strength to human and bovine dentin than BC. However, there was no significant difference in bond strength between dentin substrates, for both sealers tested. Also, there was a positive and moderate correlation between the bond strength values of human and bovine teeth. The mixed failure mode was the most prevalent. Conclusion: AP and BC provide similar filling quality, but the first presents higher bond strength values to human and bovine dentin. The use of bovine teeth as substitutes for human samples seems adequate in studies related to bond strength, but not in those testing root canal filling quality.(AU)

Capacidade de Adesão de Cimentos Biocerâmicos e Resinosos com a Dentina Radicular: Uma Revisão Integrativa / Adhesion capacity of bioceramic and resin-based root canal sealer to root dentin: an integrative review

Objetivo: comparar a capacidade de adesão do cimento biocerâmico EndoSequence BC e do cimento resinoso AH Plus através de uma revisão integrativa. Material e Métodos: os bancos de dados online Medline/PubMed, Scopus, Web of Science e BVS foram utilizados para a revisão da literatura. Os critérios de elegibilidade incluíram artigos disponíveis na íntegra nas bases de dados pesquisadas, em inglês, e o conteúdo referente à adesão do cimento Endosequence BC sealer em comparação ao AH Plus. Resultados: foram encontrados 45 artigos. Após a remoção duplicada, 22 artigos foram selecionados. Após a leitura dos resumos, textos completos e aplicação dos critérios de inclusão, foram incluídos no total oito artigos. Em relação à capacidade de adesão dos cimentos testados, o AH Plus apresentou melhor adesão do que o cimento BC sealer em três artigos e menor adesão em dois artigos. Força de adesão semelhante foi observada entre os grupos em três estudos. Conclusões: com base nos estudos incluídos, o AH Plus apresenta maior resistência de união quando comparado ao BC Sealer

Aim: To compare the adhesion capacity of the bioceramic EndoSequence BC sealer and the AH Plus sealer through an integrative review. Methodology: The Medline/PubMed, Scopus, Web of Science and VHL online databases were used for the literature review. Eligibility criteria comprised articles available in full on the researched databases, in English, and content addressing Endosequence BC sealer adhesion compared to AH Plus sealer. Results: A total of 45 articles were found. After duplicate removal, 22 articles were selected. After reading the abstracts, full texts and applying the inclusion criteria, eight articles in total were included in the present study. Concerning the adhesion capacity of the tested cements, the AH Plus was reported as presenting better adhesion than the BC sealer in three articles, and less adhesion in two articles. Similar adherence strength was observed between groups in three studies. Conclusions: Based on the included studies, the AH Plus displays greater bond strength when compared to the BC Sealer.

Impact of calcium aluminate cement with additives on dental pulp-derived cells

Abstract Calcium aluminate cement (CAC) has been highlighted as a promising alternative for endodontic use aiming at periapical tissue repair. However, its effects on dental pulp cells have been poorly explored. Objective: This study assessed the impact of calcium chloride (CaCl2) and bismuth oxide (Bi2O3) or zinc oxide (ZnO) additives on odontoblast cell response to CAC. Methodology: MDPC-23 cells were exposed for up to 14 d: 1) CAC with 2.8% CaCl2 and 25% ZnO (CACz); 2) CAC with 2.8% CaCl2 and 25% Bi2O3 (CACb); 3) CAC with 10% CaCl2 and 25% Bi2O3 (CACb+); or 4) mineral trioxide aggregate (MTA), placed on inserts. Non-exposed cultures served as control. Cell morphology, cell viability, gene expression of alkaline phosphatase (ALP), bone sialoprotein (BSP), and dentin matrix protein 1 (DMP-1), ALP activity, and extracellular matrix mineralization were evaluated. Data were compared using ANOVA (α=5%). Results: Lower cell density was detected only for MTA and CACb+ compared with Control, with areas showing reduced cell spreading. Cell viability was similar among groups at days one and three (p>0.05). CACb+ and MTA showed the lowest cell viability values at day seven (p>0.05). CACb and CACb+ promoted higher ALP and BSP expression compared with CACz (p<0.05); despite that, all cements supported ALP activity. Matrix mineralization were enhanced in CACb+ and MTA. Conclusion: In conclusion, CAC with Bi2O3, but not with ZnO, supported the expression of odontoblastic phenotype, but only the composition with 10% CaCl2 promoted mineralized matrix formation, rendering it suitable for dentin-pulp complex repair.

Biodentine Induce Proteínas Apoptóticas Caspasa 3 y PARP-1 en Células de la Pulpa Dental Humana / Biodentine Induces Apoptotic Proteins Caspase 3 and PARP - 1 on Human Dental Pulp Cells

RESUMEN: Las patologías pulpares han sido un verdadero reto para la odontología principalmente por su tratamiento. Actualmente, existen numerosos biomateriales en el mercado que reportan tener propiedades inherentes en los tejidos dentarios. Sin embargo, diferentes estudios sobre múltiples líneas celulares expuestas a estos biomateriales demuestran resultados controversiales como biocompatiblidad y citotoxicidad celular. Biodentine, es un cemento endodóntico en base a silicatos cálcico de múltiples aplicaciones, que prestaría propiedades de biocompatibilidad como bioactividad celular, características que le permitirían incluso ser utilizado en contacto directo con la pulpa dental. El objetivo de este estudio es la evaluación in-vitro de Biodentine, sobre cultivos de células de la pulpa dental humana (CCPDH). Se prepararon discos de cemento de Biodentine™ de 2 x 6 mm, los que se expusieron a cultivos de células aisladas de la pulpa dental humana. Luego de 24, 48 y 72 horas de exposición, se realizaron ensayos de viabilidad celular utilizando el método colorimétrico MTT. También se realizaron ensayos de expresión proteica de dos proteínas involucradas en la vía de señalización de la apoptosis celular: Caspasa - 3 clivada y Poli (ADP-Ribosa) Polimerasa, PARP - 1. Existen diferencias estadísticamente significativas (p<0,05) en los ensayos de viabilidad celular entre las células expuestas a Biodentine y el grupo control, como también a medida que aumenta el tiempo de exposición (p<0,05). Por otra parte, también existen diferencias significativas (p<0,05) en la expresión de PARP- 1 en los grupos sometidos a Biodentine. Los resultados obtenidos en este estudio demuestran que Biodentine genera citotoxicidad celular en cultivos celulares de pulpa dental humana, por disminución de la viabilidad celular como por la expresión de proteínas apoptóticas. Es por esto que la utilización de este biomaterial debería ser estudiado y considerarse en cada caso clínico, especialmente como recubridor pulpar directo.

ABSTRACT: Oral pathologies have been a real challenge for dentistry, mainly due to its treatment. Currently, there are numerous biomaterials on the market that may present inherent properties in dental tissues. However, studies on multiple cell lines are based on biocompatible results such as biocompatibility and cellular cytotoxicity. Biodentine is endodontic cement based on calcium silicates of multiple applications, which would provide biocompatibility properties as cellular bioactivity, characteristics that will allow it to be used in direct contact with the dental pulp. The objective of this study is the in vitro evaluation of Biodentine, on cultures of cells of the human dental pulp (HDPC). Biodentine cement disks of 2 x 6 mm were prepared, and HDPC culture plates were introduced. After 24, 48 and 72 hours of exposure, cell viability tests were performed using the MTT colorimetric method. On the other hand, protein expression assays of two proteins involved in the signaling pathway of cell apoptosis Caspase-3 cleaved (cas-3 clv) and PARP-1 are carried out. There are statistically significant differences (p <0,05) in the cell viability tests between Biodentine and control group, as well as the exposure time increases (p <0,05). Otherwise, there are also significant differences (p <0,05) in the expression of PARP-1 in the groups, sometimes a Biodentine. The results in this study that Biodentine generates a cellular cytotoxicity in HDPC cultures, therefore, cell viability as the expression of apoptotic proteins. This is why the use of this biomaterial should be studied for each particular clinical case, especially as a direct pulp capping agent.

Penetration of bioceramic and epoxy-resin endodontic cements into lateral canals

Abstract: The aim of the present study was to assess the penetration capacity of two endodontic cements, Endosequence BC Sealer and AH Plus, in artificial lateral canals. Twenty-six two-rooted, maxillary first premolars were instrumented to size 40.06 using K3 files. In each root, six lateral canals of two diameters (0.06 and 0.10 mm) were created with a working length of 2, 4, and 6 mm. The specimens were randomly divided into two groups according to the endodontic cement to be used (Endosequence BC Sealer and AH Plus) and obturated by the single-cone technique. The specimens were imaged by digital periapical radiography and scores from 0 to 4 were attributed according to the degree of penetration by sealers into the lateral canals. Data were analyzed statistically by Kruskal-Wallis and Student-Newman-Keuls tests, and a significance level of p < 0.05 was adopted. No significant difference was observed between the two endodontic cements used to fill the simulated lateral canals (p > 0.05). The diameter of lateral canals only influenced the capacity of the Endosequence BC Sealer in filling the canals, and presented greater penetration in the lateral canals of diameter 0.10 mm (p < 0.05). We concluded that the bioceramic endodontic cement Endosequence BC Sealer presented similar ability as AH Plus to fill simulated lateral canals.

Cytotoxicity and biocompatibility of a new bioceramic endodontic sealer containing calcium hydroxide

Abstract: This study evaluated the cytotoxicity and biocompatibility of a new bioceramic endodontic sealer (i.e., Sealer Plus BC) in comparison with those of MTA Fillapex and AH Plus. L929 fibroblasts were cultured and Alamar Blue was used to evaluate cell viability of diluted extracts (1:50, 1:100, and 1:200) from each sealer at 24 h. Polyethylene tubes that were filled with material or empty (as a control) were implanted in the subcutaneous tissue of rats. The rats were killed after 7 and 30 d (n = 8), and the tubes were removed for histological analysis. Parametric data was analyzed using a one-way ANOVA test, and nonparametric data was analyzed via the Kruskal-Wallis test followed by the Dunn test (p < 0.05). A reduction in cell viability was observed in the extracts that were more diluted for Sealer Plus BC when compared to that of Control and AH Plus (p < 0.05). However, the 1:50 dilution of the Sealer Plus BC was similar to that of the Control (p > 0.05). Conversely, more diluted extracts of MTA Fillapex (1:200) and AH Plus (1:100 and 1:200) were similar to the Control (p > 0.05). Histological analysis performed at 7 d did not indicate any significant difference between tissue response for all materials, and the fibrous capsule was thick (p > 0.05). At 30 d, Sealer Plus BC was similar to the Control (p > 0.05) and MTA Fillapex and AH Plus exhibited greater inflammation than the Control (p < 0.05). The fibrous capsule was thin for the Control and for most specimens of Sealer Plus BC and AH Plus. Thus, Sealer Plus BC is biocompatible when compared to MTA Fillapex and AH Plus, and it is less cytotoxic when less-diluted extracts are used.

Effect of sonic and ultrasonic activation on physicochemical properties of root canal sealers

Abstract Objective: To evaluate the effect of ultrasonic and sonic activation on physicochemical properties of AH Plus, MTA Fillapex, ADSeal, GuttaFlow Bioseal, and GuttaFlow 2 sealers. Methodology: Three experimental groups were formed: no activation (NA), ultrasonic activation (UA), and sonic activation (SA). The sealers were manipulated according to the manufacturers' instructions. A 3-mL syringe was adapted to receive 1 mL of sealer. Activation was performed with a 20/.01 ultrasonic insert (20 s/1W) in the UA group. A size 35.04 sonic tip was used (20 s/10,000 cycles/min-1) in the SA group. The molds for physicochemical analysis were filled and evaluated according to ANSI/ADA specification no. 57: setting time (ST), flow (FL), dimensional change (DC), solubility (SB), and radiopacity (RD). Statistical analysis was performed by Kruskal-Wallis, one-way ANOVA, and Tukey's tests (P<0.05). Results: Regarding ST, only AH Plus and GuttaFlow 2 in the NA group met the ANSI/ADA standards. All FL values were greater than 20 mm in diameter, as determined by ANSI/ADA. The tested sealers and protocols did not comply with the ANSI/ADA standards for DC. As for SB, only MTA Fillapex, regardless of the activation protocol, did not follow the ANSI/ADA standards. All of the investigated sealers, regardless of the activation protocol, presented radiographic density higher than 3 mm Al, as proposed by ANSI/ADA. Conclusions: UA and SA promoted changes in the physicochemical properties of the evaluated root canal sealers, mainly in ST and F. Thus, it is important to evaluate the physicochemical properties of endodontic sealers associated with activation techniques prior to clinical application in order to determine whether the properties follow the parameters set by ANSI/ADA, ensuring safety and quality of root canal filling.

Addition of zirconium oxide to Biodentine increases radiopacity and does not alter its physicochemical and biological properties

Abstract Objectives: To evaluate the radiopacity of Biodentine (BD) and BD associated with 15% calcium tungstate (BDCaWO4) or zirconium oxide (BDZrO2), by using conventional and digital radiography systems, and their physicochemical and biological properties. Materials and Methods: Radiopacity was evaluated by taking radiographs of cement specimens (n=8) using occlusal film, photostimulable phosphor plates or digital sensors. Solubility, setting time, pH, cytocompatibility and osteogenic potential were also evaluated. Data were analyzed using one-way ANOVA and Tukey post-test or two-way ANOVA and Bonferroni post-test (α=0.05). Results: BD radiopacity was lower than 3 mm Al, while BD ZrO2 and BD CaWO4 radiopacity was higher than 3 mm Al in all radiography systems. The cements showed low solubility, except for BDCaWO4. All cements showed alkaline pH and setting time lower than 34 minutes. MTT and NR assays revealed that cements had greater or similar cytocompatibility in comparison with control. The ALP activity in all groups was similar or greater than the control. All cements induced greater production of mineralized nodules than control. Conclusions: Addition of 15% ZrO2 or CaWO4 was sufficient to increase the radiopacity of BD to values higher than 3 mm Al. BD associated with radiopacifiers showed suitable properties of setting time, pH and solubility, except for BDCaWO4, which showed the highest solubility. All cements had cytocompatibility and potential to induce mineralization in Saos-2 cells. The results showed that adding 15% ZrO2 increases the radiopacity of BD, allowing its radiography detection without altering its physicochemical and biological properties.

Surface and vertical dimensional changes of mineral trioxide aggregate and biodentine in different environmental conditions

Abstract Surface changes in biological environments are critical for the evaluation of physical and biological activity of biomaterials. Objective: This study investigated surface alterations of calcium silicate-based cements after exposure to different environments. Material and Methods: Forty-eight cylindrical cavities were prepared on root surfaces. The cavities were filled using ProRoot MTA or Biodentine and assigned to four subgroups (n=6): dry, wet, acidic, and blood. Surface topographies were evaluated using an optical profilometer for 28 days, and the roughness of the material surfaces was quantified. Vertical dimensional change was measured by determining the height difference between the material surface and the flat tooth surface. Data were compared with a two-way repeated measures ANOVA and Bonferroni tests. Results: In dry condition, the surface roughness of MTA or Biodentine was constant up to 3 days (p>0.05) but decreased after 28 days (p<0.05). In dry condition, ProRoot MTA presented constant surface level through time, while Biodentine showed decreased surface level after 28 days. In wet condition, the roughness and the surface levels of both materials increased after 1 day (p<0.05). Neither the surface roughness nor the levels of the materials showed significant changes in acidic conditions (p>0.05). Both materials showed the highest roughness in blood conditions on the 1st day (p<0.05), while the surface roughness in blood decreased dramatically after 28 days. The roughness of Biodentine was higher in wet conditions up to 3 days compared with ProRoot MTA (p<0.05). Likewise, in blood condition, Biodentine showed higher roughness on the 28th day than ProRoot MTA (p<0.05). Conclusions: Dry, wet, and blood conditions had a time-dependent effect on the surface roughness and vertical dimensional changes of the materials. However, acidic conditions did not affect the roughness and the surface level of the materials.

Effects of dodecacalcium hepta-aluminate content on the setting time, compressive strength, alkalinity, and cytocompatibility of tricalcium silicate cement

Abstract Objective This study aimed to investigate the effects of dodecacalcium hepta-aluminate (C12A7) content on some physicochemical properties and cytocompatibility of tricalcium silicate (C3S) cement using human dental pulp cells (hDPCs). Material and Methods High purity C3S cement was manufactured by a solid phase method. C12A7 was mixed with the cement in proportions of 0, 5, 8, and 10 wt% (C12A7-0, −5, −8, and −10, respectively). Physicochemical properties including initial setting time, compressive strength, and alkalinity were evaluated. Cytocompatibility was assessed with cell viability tests and cell number counts. Statistical analysis was performed by using one-way analysis of variance (ANOVA) and Tukey's test (p<0.05). Results The initial setting time of C3S-based cement was shorter in the presence of C12A7 (p<0.05). After 1 day, C12A7-5 showed significantly higher compressive strength than the other groups (p<0.05). After 7 days, the compressive strength of C12A7-5 was similar to that of C12A7-0, whereas other groups showed strength lower than C12A7-0. The pH values of all tested groups showed no significant differences after 1 day (p>0.05). The C12A7-5 group showed similar cell viability to the C12A7-0 group (p>0.05), while the other experimental groups showed lower values compared to C12A7-0 group (p<0.05). The number of cells grown on the C12A7-5 specimen was higher than that on C12A7-8 and −10 (p<0.05). Conclusions The addition of C12A7 to C3S cement at a proportion of 5% resulted in rapid initial setting time and higher compressive strength with no adverse effects on cytocompatibility.

Evaluation of physicochemical properties of new calcium silicate-based sealer

Abstract This study aimed to evaluate the physicochemical properties of a calcium silicate-based sealer (Sealer Plus BC; MK Life, Porto Alegre, Brazil) compared with an epoxy-resin sealer (AH Plus; Dentsply DeTrey GmbH, Konstanz, Germany). Initial and final setting time was assessed based on ISO 6876:2012 and ASTM C266:03. Calcium ion release and pH were evaluated by filling polyethylene tubes with sealers and then immersing them in 10 mL of deionized water. Following experimental periods of 1, 24, 72 and 168 hours, the samples were measured regarding pH and calcium ion release with a pH meter and a colorimetric spectrophotometer, respectively. The flow was examined based on ISO 6876:2012. Rings of 10 mm in diameter with 1 mm thickness were prepared to analyze the radiopacity (ISO 6876:2012 and ADA n.57) and solubility (ISO 6876:2012). The data were analyzed by variance analysis, Student-T and Tukey tests (p<0.05). The calcium ion release and pH values were significantly higher for the Sealer Plus BC compared with the AH Plus (p<0.05). Lower setting time, flow and radiopacity were observed for the bioceramic sealer than for AH Plus (p<0.05). Sealer Plus BC exhibited higher solubility compared with AH Plus (p<0.05). Sealer Plus BC showed physicochemical properties as setting time, pH, calcium release, flow, and radiopacity following the required standards, but higher solubility than the minimum values required by ISO 6876:2012.

Resumo Este estudo teve por objetivo avaliar as propriedades físico-químicas de um cimento à base de silicato de cálcio (Sealer Plus BC MK Life, Porto Alegre, Brasil) e compará-las a um cimento à base de resina epóxica (AH Plus, Dentsply DeTrey GmbH, Konstanz, Alemanha). Tempo de presa inicial e final foram avaliados com base na ISO 6876:2012 e ASTM C266:03. Liberação de íons cálcio e pH foram avaliados após o preenchimento de tubos de polietileno com os cimentos e imersão em 10 mL de água deionizada. Após os tempos experimentais de 1,24,72 e 168 horas, os valores de pH e liberação de íons cálcio foram mensurados utilizando um medidor de pH e um espectofotômetro colorimétrico, respectivamente. Escoamento foi avaliado com base na ISO 6876:2012. Moldes de 10 mm de diâmetro e 1 mm de espessura foram preparados para análise de radiopacidade (ISO 6876:2012 e ADA n.57), solubilidade (ISO 6876:2012). Os dados foram analisados por análise de variância, teste T de Student e teste de Tukey (p<0,05). A liberação de íons cálcio e os valores de pH foram significativamente maiores para o Sealer Plus BC em comparação com o AH Plus (p<0,05). Menores valores de tempo de presa, escoamento e radiopacidade foram observados para o cimento biocerâmico quando comparados com o AH Plus (p<0,05). Sealer Plus BC apresentou propriedades físico-químicas de tempo de presa, pH, liberação de íons cálcio, escoamento, radiopacidade de acordo com as normas exigidas, porém maior solubilidade que aquelas previstas pela ISO 6876:2012.

Radiopacity and Chemical Assessment of New Commercial Calcium Silicate-Based Cements / Radiopacidad y Evaluación Química de Cementos Comerciales en Base a Silicato de Calcio

ABSTRACT: The aim of the study was to evaluate the chemical composition and radiopacity of new calcium-silicatebased cements. Discs of 10 mm x 1 ± 0.1mm were prepared of BiodentineTM, TheraCal, Dycal and GC Fuji IX (n=5). The samples were radiographed directly on an PSP occlusal plate adjacent to an aluminium step wedge. The radiopacity of each specimen was determined according to ISO 9917/2007. Statistical analyses were carried out using ANOVA and Tukey's test at a significance level of 5 %. The chemical constitution of materials was determined by scanning electron microscopy (SEM) and energy dispersive x-ray element mapping. The radiopacities of the materials in decreasing order were: GC Fuji IX (3.45 ± 0.16 mm), Dycal (3.18 ± 0.17), BiodentineTM (2.79 ± 0.22), and TheraCal (2.17 ± 0.17). TheraCal showed the lowest radiopacity compared to the other materials, followed by BiodentineTM. Dycal and GC Fuji IX radiopacity values did not present significant statistical differences. Scanning electron microscopy and energy dispersive X-ray analysis revealed the presence of zirconium in BiodentineTM; and strontium, barium and zirconium in TheraCal as radiopacifying elements. The new calcium silicate cements present distinctive chemical composition. BiodentineTM contains zirconium as a radiopacifying element and has higher radiopacity values than TheraCal, which contains barium and strontium as radiopacifiers.

RESUMEN: El objetivo de este estudio fue evaluar la composición química y la radiopacidad de nuevos cementos en base a silicato de calcio. Discos de 10 mm x 1 ± 0,1 mm fueron preparados con BiodentineTM, TheraCal, Dycal y GC Fuji IX (n=5). Las muestras fueron radiografiadas directamente en una película PSP oclusal adyacente a una cuña escalonada de aluminio. La radiopacidad de cada espécimen fue determinada de acuerdo a la norma ISO 9917/ 2007. Se realizaron los análisis estadísticos con las pruebas ANOVA y test de Tukey con un nivel de significancia de 5 %. La constitución química de los materiales fue determinada con microscopía electrónica de barrido y con mapeo por análisis con dispersión de energía de rayos X. La radiopacidad de los materiales en orden decreciente fue: GC Fuji IX (3,45 ± 0,16 mm), Dycal (3,18 ± 0,7 mm), BiodentineTM (2,79 ± 0,22 mm), y TheraCal (2,17 ± 0,17 mm). TheraCal mostró la menor radiopacidad comparada con los otros materiales, seguido de BiodentineTM. Los valores de radiopacidad de Dycal y GC Fuji IX no presentaron diferencias estadísticas significativas. Los análisis de microscopía electrónica de barrido y mapeo por análisis con dispersión de energía de rayos X revelaron la presencia de zirconio en BiodentineTM; y de estroncio, bario y zirconio en TheraCal, como elementos radiopacos. Los nuevos cementos en base a silicato de calcio presentan una composición química distintiva. BiodentineTM contienen zirconio como elemento que provee radiopacidad y tiene mayor valor de radiopacidad que TheraCal, el cual contiene bario y estroncio como agente radiopaco.

Ytterbium oxide as radiopacifier of calcium silicate-based cements. physicochemical and biological properties

Abstract This study evaluated physicochemical properties, cytotoxicity and bioactivity of MTA Angelus (MTA), calcium silicate-based cement (CSC) and CSC with 30% Ytterbium oxide (CSC/Yb2O3). Setting time was evaluated using Gilmore needles. Compressive strength was evaluated in a mechanical machine. Radiopacity was evaluated using radiographs of materials and an aluminum scale. Solubility was evaluated after immersion in water. Cell viability was evaluated by means of MTT assay and neutral red staining, and the mineralization activity by using alkaline phosphatase activity and Alizarin Red staining. The data were submitted to ANOVA, Tukey and Bonferroni tests (5% significance). The bioactive potential was evaluated by scanning electron microscopy. The materials presented similar setting time. MTA showed the lowest compressive strength. MTA and CSC/Yb2O3 presented similar radiopacity. CSC/Yb2O3 showed low solubility. Saos-2 cell viability tests showed no cytotoxic effect, except to 1:1 dilution in NR assay which had lower cell viability when compared to the control. ALP at 1 and 7 days was similar to the control. MTA and CSC had greater ALP activity at 3 days when compared to control. All the materials present higher mineralized nodules when compared with the control. SEM analysis showed structures suggesting the presence of calcium phosphate on the surface of materials demonstrating bioactivity. Ytterbium oxide proved to be a properly radiopacifying agent for calcium silicate-based cement since it did not affected the physicochemical and biological properties besides preserving the bioactive potential of this material.

Resumo Este estudo avaliou as propriedades físico-químicas, citotoxicidade e bioatividade do MTA Angelus (MTA), cimento à base de silicato de cálcio (CSC) e CSC com 30% de óxido de itérbio (CSC/Yb2O3). O tempo de presa foi avaliado usando agulhas Gilmore. A resistência à compressão foi avaliada em uma máquina mecânica. A radiopacidade foi avaliada utilizando radiografias dos materiais e uma escala de alumínio. A solubilidade foi avaliada após imersão em água. A viabilidade celular foi avaliada por meio do ensaio MTT e coloração de vermelho neutro (NR), e a atividade de mineralização por meio da atividade da fosfatase alcalina e a coloração com Vermelho de Alizarina. Os dados foram submetidos aos testes ANOVA, Tukey e Bonferroni (5% de significância). O potencial bioativo foi avaliado por microscopia eletrônica de varredura. Os materiais apresentaram tempo de presa semelhante. O MTA mostrou menor resistência à compressão. MTA e CSC/Yb2O3 apresentaram radiopacidade semelhante. CSC/Yb2O3 apresentou menores valores de solubilidade. A viabilidade celular realizada pelos ensaios de MTT e NR não revelaram efeitos ctotóxicos em todas as diluições, exceto na diluição 1:1 no NR, o qual mostrou baixa viabilidade celular (p<0.05) em todos materiais testados quando comparado ao controle. A atividade de ALP em 1 e 7 dias foi similar ao controle (p>0.05). MTA e CSC tiveram significante aumento na atividade de ALP aos 3 dias quando comarados ao controle (p>0.05). Todos os materiais apresentaram grande produção de nódulos mineralizados quando comparados ao controle (P<0.05). A análise da SEM mostrou estruturas que sugerem a presença de depósitos de fosfato de cálcio na superfície dos materiais demonstrando bioatividade. O Yb2O3 mostrou ser um agente radiopacificador adequado em cimentos à base de silicato de cálcio uma vez que não afetou as propriedades físico-químicas e biológicas e ainda preservou o potencial bioativo desse material.

Can the application of multi-mode adhesive be a substitute to silicatized/silanized y-tzp ceramics?

Abstract This study evaluated the effectiveness of a multi-mode adhesive (SBU-Scotch Bond Universal/3M) as a substitute for silica coating and silane application on the bonding of zirconia ceramics to resin cement. One-hundred and twenty sintered zirconia ceramic blocks (5 x 5 x 5 mm) were obtained, finished by grounding with silicon carbide paper (#600, #800, #1000 and #1200) and randomly divided into 12 groups (n=10) in accordance with the factors "surface treatment" (ScSi - silicatization + silanization; ScSBU - silicatization + SBU; SBU - SBU without photoactivation and SBUp - SBU photoactivated) and "ceramic" (Lava / 3M ESPE, Ceramill Zirconia / Amann Girrbach and Zirkonzahn / Zirkonzahn). Dual resin cement cylinders (RelyX Ultimate/3M ESPE) were subsequently produced in the center of each block using a silicon matrix (Ø=2 mm, h=5 mm) and photoactivated for 40 s (1200 mW/cm2). The samples were stored for 30 days in distilled water (37ºC) and submitted to shear bond strength test (1 mm/min, 100 KgF). Data (MPa) were analyzed under ANOVA (2 levels) and Tukey test (5%). Complementary analyzes were also performed. ANOVA revealed that only the factor "surface treatment" was significant (p=0.0001). The ScSi treatment (14.28A) promoted statistically higher bond strength values than the other ScSBU (9.03B), SBU (8.47B) and SBUp (7.82B), which were similar to each other (Tukey). Failure analysis revealed that 100% of the failures were mixed. The silica coating followed by the silanization promoted higher bond strength values of resin cement and ceramic, regardless of the zirconia ceramic or SBU.

Resumo Este estudo avaliou a efetividade de um adesivo "multi-mode" (Single Bond Universal/3M) como um substituto para a silicatização e aplicação do silano na resistência de união das cerâmicas de zircônia e um cimento resinoso. Para isso, 120 blocos cerâmicos sinterizados de zircônia nas dimensões de (5 x 5 x 5 mm) foram obtidos, lixados com lixas de granulação decrescente (#600, #800, #1000 e #1200) e divididos aleatoriamente em 12 grupos (n = 10), de acordo com os fatores "tratamento de superfície" (ScSi - silicatização + silanização; ScSBU - silicatização + Single Bond; SBU - SBU sem fotoativação e SBUp - SBU com fotoativação) e "cerâmica" (Lava/3M ESPE, Ceramill Zircônia/ Amann Girrbach e Zirkonzahn/Zirkonzahn). Posteriormente, cilindros de cimento resinoso dual (RelyX Ultimate/3M ESPE) foram confeccionados no centro de cada bloco com auxílio de uma matriz de silicone (Ø=2 mm; h=5 mm) e fotopolimerizados por 40 s (1200 mW/ cm²). Em seguida, as amostras foram armazenadas durante trinta dias em água destilada (37 °C) e submetidas ao ensaio de resistência de união ao cisalhamento (1 mm/min, 100 kgF). Os dados (MPa) foram analisados sob ANOVA (2 fatores) e teste de Tukey (5%). Análises complementares também foram realizadas. ANOVA revelou que apenas o fator "tratamento de superfície" foi significativo (p=0,0001). O tratamento ScSi (14.28A) promoveu valores de adesão estatisticamente superiores aos demais ScSBU (9.03B), SBU (8.47B) e SBUp (7.82B), os quais foram semelhantes entre si (Tukey). A Análise de falhas revelou que 100% da falhas que ocorreram foram mistas. A silicatização seguida da silanização promoveu a melhor resistência de união entre cimento resinoso e a cerâmica, independentemente do tipo da cerâmica ou do SBU.

Effect of blood contamination on the push-out bond strength of calcium silicate cements

Abstract This study investigated the effect of blood-contamination on the push-out bond strength of BiodentineTM (BD) and MTA Angelus® (MTA-A) to root dentin over time. Twenty-five teeth were sectioned horizontally to obtain 120 root slices. The lumens were filled with MTA-A or BD: 60 for each cement (30 uncontaminated and 30 blood contaminated). Push out bond strength to dentin was assessed at 24 h (n=10), 7 days (n=10) and 28 days (n=10). Failure modes were classified as: cohesive, adhesive or mixed failure. Two-way ANOVA was used to investigate the interaction between blood contamination vs. hydration period. Mann Whitney test compared different materials in each period, and it also compared the contaminated versus uncontaminated material for each period. Friedman, followed by Dunn`s test, compared periods of hydration for each material, regardless of blood contamination. Failure modes were reported descriptively. The interaction hydration period vs. blood contamination was highly significant for MTA-A (P=0.001) and it was not significant for BD (P=0.474). There were no differences between bond strength of uncontaminated and contaminated BD in any of the periods. Bond strength of uncontaminated MTA-A increased at each time of hydration; but it remained stable over time for blood-contaminated samples. BD had higher bond strength than MTA-A in all periods of hydration. Cohesive failure predominated. Only for MTA-A, the over time bond strength to dentin was affected by blood contamination.

Resumo Este estudo investigou o efeito da contaminação sanguínea na resistência de união do BiodentineTM (BD) e do MTA Angelus® (MTA-A) à dentina, em diferentes períodos. Vinte e cinco dentes foram seccionados para obter 120 fatias de dentina. Os lúmens das fatias foram preenchidos com MTA-A ou BD: 60 para cada cimento (30 não-contaminados e 30 contaminados com sangue). A resistência de união à dentina foi medida por teste push-out em 24 horas (n=10), 7 dias (n=10) e 28 dias (n=10). Os tipos de falha foram classificados como: falha coesiva, adesiva ou mista. Two-way ANOVA foi usado para investigar a interação entre contaminação sanguínea vs. período de hidratação. O teste de Mann Whitney comparou os diferentes materiais em cada período, e comparou as amostras contaminadas e não contaminadas de cada material em cada tempo. O teste de Friedman, seguido pelo teste de Dunn, comparou os períodos de hidratação de cada material, independentemente da contaminação. A análise estatística mostrou a interação entre contaminação sanguínea vs. período de hidratação. Os tipos de falha foram reportados de maneira descritiva. A interação entre contaminação sanguínea vs. período de hidratação foi altamente significativa para o MTA-A (P=0,001), e não foi significativa para o BD (P=0,474). Não houve diferenças entre a resistência de união entre o BD contaminado e não-contaminado independente do período. A resistência de união do MTA-A não-contaminado aumentou a cada tempo de hidratação; mas, permaneceu estável ao longo do tempo para as amostras contaminadas com sangue. BD obteve maior resistência de união que o MTA-A em todos os períodos de hidratação. Falhas coesivas predominaram. A contaminação ao longo do tempo influenciou a resistência de união no grupo MTA-A.

Bond strength of experimental root canal sealers based on mta and butyl ethylene glycol disalicylate

Abstract This study investigated the bond strength of two experimental root canal sealers based on MTA and butyl ethylene glycol disalicylate: MTAe and MTAe-HA. The reference materials used for comparison were AH Plus and MTA Fillapex. Twenty human upper incisors were selected and one 1 mm slice was obtained from the cervical third of each root. On the coronal surface of each slice, four 0.9 mm wide holes were drilled through the dentine. Standardized irrigation was performed and holes were filled with one of the four tested sealers: AH Plus, MTA Fillapex, MTAe, and MTAe-HA. The filled slices were stored in a PBS solution (pH 7.2) for 7 days at 37 °C. A push-out assessment was performed with a 0.7 mm plunger tip. Load was applied at a crosshead speed of 0.5 mm/min until sealer displacement. The results were expressed in MPa. The Kruskal-Wallis test was applied to assess the effect of each sealer on the push-out bond strength. Mann-Whitney with Bonferroni correction was used to isolate the differences. The alpha-type error was set at 0.05. Significant differences among medians values obtained by materials were observed (p<0.001). AH Plus displayed the highest value of bond strength (p<0.001). In contrast, MTA Fillapex presented the lowest bond strength among all tested sealers (p<0.001). Experimental sealers showed intermediary bond strength values, with no statistical differences between them (p>0.05). In conclusion, experimental root canal sealers presented suitable bond strength outcomes when compared to MTA Fillapex.

Resumo Esse estudo investigou a resistência de união de dois cimentos endodônticos experimentais à base de MTA e butiletilenoglicol dissalicilato: MTAe e MTAe. Os materiais de referência utilizados para comparação foram os cimentos endodônticos MTA Fillapex e AH Plus. Vinte incisivos superiores humanos foram selecionados e um slice dentinário de 1 mm de espessura foi obtido do terço cervical de cada raiz. Na superfície coronária de cada slice, quatro orifícios com 0,9 mm de diâmetro foram confeccionados através da dentina. Uma irrigação padronizada foi realizada e os orifícios foram preenchidos com um dos quatro cimentos endodônticos avaliados: AH Plus, MTA Fillapex, MTAe, e MTAe-HA. Os slices preenchidos foram armazenados em solução PBS (pH 7,2) durante 7 dias a 37°C. O ensaio de push-out foi realizado por meio de um dispositivo com 0,7 mm de diâmetro. A carga foi aplicada com a velocidade de 0,5 mm/min até a obtenção de deslocamento do material obturador. Os resultados foram expressos em MPa. O teste de Kruskal-Wallis foi aplicado para avaliar o efeito da resistência de união de cada cimento endodôntico. O teste de Mann-Whitney com correção de Bonferroni foi utilizado para isolamento das diferenças. O erro do tipo-alfa foi fixado em 0,05. Diferenças significantes entre os valores de medianas obtidos pelos materiais foram observados (p<0,001). O AH Plus demonstrou os maiores valores de resistência de união (p<0,001). Em contraste, o MTA Fillapex apresentou a menor resistência de união entre todos os cimentos testados (p<0,001). Os cimentos experimentais demonstraram valores intermediários, com ausência de diferenças estatísticas entre si (p>0,05). Em conclusão, os cimentos endodônticos experimentais à base de MTA e butiletilenoglicol dissalicilato apresentaram resultados adequados de resistência de união quando comparados ao MTA Fillapex.

Push-out bond strength of different tricalcium silicate-based filling materials to root dentin

Abstract: The aim of this study was to evaluate the bond strength of different triccalcium silicate cements to retrograde cavity using a push out test. Thirty maxillary central incisors were shaped using #80 hand files and sectioned transversally. Root slices were obtained from the apical 4 mm after eliminating the apical extremity. The specimens were embedded in acrylic resin and positioned at 45° to the horizontal plane for preparation of root-end cavities with a diamond ultrasonic retrotip. The samples were divided into three groups according to the root-end filling material (n = 10): MTA Angelus, ProRoot MTA and Biodentine. A gutta-percha cone (#80) was tugged-back at the limit between the canal and the root-end cavity. The root-end cavity was filled and the gutta-percha cone was removed after complete setting of the materials. The specimens were placed in an Instron machine with the root-end filling turned downwards. The push-out shaft was inserted in the space previously occupied by the gutta-percha cone and push out testing was performed at a crosshead speed of 1.0 mm/min. There was no statistically significant difference in resistance to push out by the materials tested (p > 0.01). MTA Angelus and ProRoot MTA showed predominantly mixed failure while Biodentine exhibited mixed and cohesive failures. The tricalcium silicate-based root-end filling materials showed similar bond strength retrograde cavity.

Tricalcium silicate-based cements: properties and modifications

Abstract: Mineral trioxide aggregate (MTA) has been widely used for different reparative procedures in endodontics. The extensive use of this cement for pulp capping, apexifications, apical surgeries, and revascularization is related to its ability to induce tissue repair and to stimulate mineralization. Several research studies have tested modifications in the composition of MTA-based cements in order to enhance their clinical performance. Novel formulations have been introduced in the market with the aim of increasing flowability. Important properties such as appropriate radiopacity and setting time, color stability, alkaline pH, release of calcium ions, and biocompatibility have to be considered in these new formulations. The latest research studies on the physical, chemical, and biological properties of tricalcium silicate-based cements are discussed in this critical review.

Evaluation of the sealing ability of different root canal sealers: a combined SEM and micro-CT study

Abstract Objective: The purpose of this study was to analyze the ability of multiple compounds to seal the dental tubules using scanning electron microscopy (SEM) and micro-computed tomogra-phy (micro-CT). Material and Methods: Twenty-four single-root human mandibular premolars were selected and instrumented with nickel-titanium rotary file and the final file size was #40/06. They were then randomly allocated into 2 groups, and all samples were filled with single cone gutta-percha (#40/06) and one of the tested sealers (AH Plus and EndoSequence BC sealers). All specimens were scanned using micro-CT and then three from each group were randomly selected for SEM analysis. Results: According to SEM, both root canal sealers showed sufficient adaptation to dentin along the whole length of the root canal, though the coronal sections presented superior sealing than the apical sections. Micro porosity analyses revealed that the volume of closed pores and the surface of closed pores had the largest values in the coronal sections, followed by the middle and the apical sections for both sealants (p<0.05). However, no significant difference was observed for those two parameters between AH Plus and EndoSequence BC sealers in any of the three sections (p>0.05), whereas they were larger in the apical section when the AH Plus sealer was used. Conclusions: By using the single cone technique, neither EndoSequence or AH Plus pro-vides a porosity-free root canal filling. The EndoSequence BC sealer may have similar sealing abilities regarding the whole root canal as the AH Plus sealer. A better sealing effect could be obtained in the coronal and middle sections of a root canal than the apical part by using the tested sealers.