The effects of heating on the physicochemical properties of tricalcium silicate root canal sealers

Abstract This study evaluated the effect of heating on the physicochemical properties and surface changes of tricalcium silicate sealers. Three tricalcium silicate root canal sealers (Bio-C Sealer, BioRoot-RCS, EndoSequence BC Sealer), and one epoxy resin-based sealer (AH Plus; control) were tested. The effect of heating on setting time (ST) and flowability were assessed according to ANSI/ADA 57 and ISO 6876 standards. Solubility and dimensional change (DC) of the set sealers were evaluated at 24 hours and after 30 days; the pH of the water used in the DC testing was also measured. Tests were repeated with heated sealers in an oven at 100 °C for 1 min. SEM and EDS analysis were performed. Data were analyzed using One-Way ANOVA and Tukey post-hoc tests (α=5%). Heating decreased the ST for AH Plus and EndoSequence (p<0.05). Heating reduced flowability (p<0.05) and increased pH for AH Plus (p<0.05). The solubility of Bio-C (dried specimens) was not in accordance with the ANSI/ADA standard. The solubility of EndoSequence was significantly higher (p<0.05) when it was heated and dried after 30 days. DC of Bio-C (24 h and 30 days), BioRoot-RCS (30 days) and AH Plus (24 h and 30 days) were not in accordance with the standards. SEM and EDS analysis showed significant changes in sealer microstructure after heating. In conclusion, heating decreased the ST and increased the solubility of EndoSequence BC sealer. No significant changes in flowability, DC, and pH were identified for all three tricalcium silicate sealers after heat application. However, all sealers had significant surface changes.

Resumo Este estudo avaliou o efeito do aquecimento nas propriedades físico-químicas e nas alterações superficiais de cimentos de silicato tricálcico. Três cimentos endodônticos de silicato tricálcico (Bio-C Sealer, BioRoot-RCS, EndoSequence BC Sealer) e um cimento à base de resina epóxi (AH Plus) foram testados para avaliar o efeito do aquecimento no tempo de presa (TP) e escoamento de acordo com as normas ANSI/ADA 57 e ISO 6876. A solubilidade e alteração dimensional (AD) dos cimentos foram avaliadas após 24 horas e 30 dias. O pH da água usada no teste de AD também foi medido. Os testes foram repetidos com cimentos aquecidos em um forno a 100 °C por 1 min. Análises em MEV e EDS foram realizadas. Os dados foram analisados pelos testes de ANOVA-1 via e post hoc de Tukey (α=5%). O aquecimento diminuiu o TP para AH Plus e EndoSequence (p<0,05). O aquecimento reduziu o escoamento (p<0,05) e aumentou o pH do AH Plus (p<0,05). A solubilidade do Bio-C (amostras desidratadas) não estava de acordo com o padrão ANSI/ADA. A solubilidade da EndoSequence foi significativamente maior (p<0,05) quando aquecida e desidratada após 30 dias. As AD de Bio-C (24 h e 30 dias), BioRoot-RCS (30 dias) e AH Plus (24 h e 30 dias) não estavam de acordo com as normas ADA e ISO. A análise em MEV e EDS mostrou alterações significativas na estrutura dos cimentos após aquecimento. Em conclusão, o aquecimento diminuiu o TP e aumentou a solubilidade do cimento EndoSequence BC. Não foram identificadas mudanças significativas no escoamento, AD e pH para os cimentos de silicato tricálcico após aquecimento. Porém, todos os cimentos tiveram alterações significativas na superfície.

A comparative study on apical sealing performance between single cone obturation and warm gutta-percha root canal filling / 口腔医学

Objective@#To compare the sealing performance of three kinds of sealers AH-Plus, iRoot SP and GuttaFlow2 combined with single cone obturation and warm gutta-percha root canal filling.@*Methods@#Seventy premolars with single root canal were extracted recently and prepped to P# by Waveone gold system after truncating tooth crown. Then they were randomly divided into 6 experimental groups (10 premolars per group) and 2 control groups (5 premolars per group). Single tip filling and warm gutta-percha filling were performed, namely AH-Plus single tip filling group (A1), AH-Plus warm gutta-percha filling group (A2), iRoot SP single tip filling group (B1), iRoot SP warm gutta-percha filling group (B2), GuttaFlow2 single tip filling group (C1), GuttaFlow2 warm gutta-percha group (C2), positive control group (D group) and negative control group (E group). After dye penetration test was performed on the filled teeth, microleakage of root tip was detected by longitudinal section method. @*Results@#A1 group had the largest microleakage value, while B2 group had the smallest microleakage value. There was no statistically significant difference in apical sealing between single-tip filling and hot dental glue filling with the same sealant (P>0.05), and also no statistically significant difference in apical sealing between the three kinds of sealant with the same filling technology (P>0.05).@*Conclusion@#None of the three root canal sealers can completely seal the root canal, and there is no significant difference in the sealing effect between single tip filling and warm gutta-percha filling.

Physico-chemical properties of calcium silicate-based sealers in powder/liquid and ready-to-use forms

Abstract Calcium silicate-based root canal sealers have been developed in powder/liquid or premixed ready-to-use forms. The evaluation of the physico-chemical properties of a prototype powder/liquid MTApex Sealer (Ultradent) in comparison to a ready-to-use material EndoSequence BC Sealer (Brasseler) was performed. The paste/paste epoxy resin-based AH Plus (Dentsply) served as control for comparisons. The sealers were evaluated (n = 6) regarding setting time (in dry and moist environments), flow and radiopacity, following the ISO-6876/2012 standard. Also, the pH was assessed. Material's surface and chemical characterization was evaluated using scanning-electron-microscopy (SEM) and energy-dispersive-spectrometry (EDS). Mixed ANOVA, Shapiro-Wilk, Levene, and post-hoc analysis with Bonferroni correction were performed at a significance level of 5%. MTApex Sealer exhibited the highest flow and EndoSequence BC Sealer had a significantly longer setting time in dry compared to the moist environment; however, for MTApex Sealer and AH Plus no significant changes occurred when additional moisture was provided. All materials exceeded 7 mm Al of radiopacity and showed a decreasing alkalinity over the 21 day-analysis. SEM/EDS evaluation resulted in peaks of calcium, silicon, and the respective radiopacifier. The prototype powder/liquid MTApex Sealer had the highest flow and similar setting time in both dry and moist environments; opposingly, EndoSequence BC Sealer was crucially influenced by external moisture. This suggests that the powder/liquid materials' setting seems to be more predictable.

Resumo Os cimentos endodônticos obturadores à base de silicato de cálcio foram desenvolvidos em formas pó/líquido ou pré-misturadas prontas para o uso. Foi realizada a avaliação das propriedades físico-químicas de um protótipo pó/líquido MTApex Sealer (Ultradent) em comparação com um material pronto para uso EndoSequence BC Sealer (Brasseler). O cimento obturador pasta/pasta à base de resina epóxi AH Plus (Dentsply) serviu de controle para as comparações. Os cimentos foram avaliados (n = 6) quanto a: tempo de presa (em ambientes secos e úmidos), escoamento e radiopacidade, seguindo a norma ISO-6876/2012; como também o pH. A superfície do material e a caracterização química foram realizadas utilizando a microscopia eletrônica de varredura (MEV) e espectrometria dispersiva de energia (EDS). ANOVA, Shapiro-Wilk, Levene e análise post-hoc com correção de Bonferroni foram realizadas com nível de significância de 5%. O MTApex Sealer exibiu um escoamento mais alto e o EndoSequence BC Sealer teve um tempo de presa significativamente mais longo em ambiente seco em comparação com o ambiente úmido; entretanto, para MTApex Sealer e AH Plus, nenhuma mudança significativa ocorreu quando umidade adicional foi fornecida. Todos os materiais excederam 7 mm de Al de radiopacidade e mostraram uma alcalinidade decrescente ao longo dos 21 dias de análise. A avaliação MEV/EDS resultou em picos de cálcio, silício e respectivo radiopacificador. O protótipo de pó/líquido MTApex Sealer teve o maior escoamento e tempo de presa semelhante em ambientes secos e úmidos; ao contrário, o EndoSequence BC Sealer foi influenciado de maneira crucial pela umidade externa. Isso sugere que a configuração dos materiais em pó/líquido parece ser mais previsível.

A comparison of the physicochemical properties of AH Plus Jet with samples taken from the beginning, middle and final portions of the automix syringe system

Aim To evaluate physicochemical properties and semi-quantitative elemental analysis of AH Plus Jet with samples from the beginning, middle and final portions of the automix syringe system. Methodology Three experimental groups based on the source of the material used (beginning, middle and final portion) were established for each of the evaluated properties. Setting time, flow and radiopacity were evaluate following ANSI/ADA n. 57 specification. Set specimens was used in the semi-quantitative elemental analysis in an energy-dispersive X ray spectroscopy and scanning-electron microscopy (EDS/SEM). Statistical analysis was performed using one-way ANOVA followed by Tukey test (P<0.05). Results Flow, setting time, solubility and EDS/SEM tests showed no significant differences among the three portions of the automix syringe (P>0.05). Radiopacity test showed significant differences in the beginning of the syringe comparing to the middle and final portions (P<0.05). EDS/SEM analysis identified the presence of C, O, Al, Ca, Zr and W. The element Al, however, was found only in the final portion of the syringe. Conclusions The results of AH Plus Jet suggested an adequate ratio of the components, without segregation between organic and inorganic components, since the results of setting time, flow, solubility and EDS/SEM analysis presented similar values regardless of the portion of the syringe from where the sealer was taken.

Energy-Dispersive X-Ray Spectrometry Analysis and Radiopacity of Five Different Root Canal Sealers

Abstract Root canal sealers should have optimum adhesion to the root dentin, low cytotoxicity, sufficient radiopacity and high dimensional stability, which depend mainly on their chemical composition. The aims of this study were to evaluate the chemical composition of Syntex (Cerkamed, Stalowa Wola, Poland), Adseal (Meta Biomed, Cheongju-si, Korea), Sealapex (SybronEndo, Scafati, Italy), MTA Fillapex (Angelus, Londrina, Brazil) and GuttaFlow Bioseal (Coltene/Whaledent, Altstätten, Switzerland) and to determine their radiopacity comparatively. Stainless steel molds with an inner diameter of 5 mm and a depth of 2 mm were constructed. Tested root-canal sealers were mixed and poured into the molds. Following setting, digital periapical radiographs of the specimens (n=12) were taken under standard exposure conditions and the mean gray-values of specimens were measured using a computer graphics program. Then the specimens were examined by scanning electron microscopy, and Energy-dispersive X-ray analysis was performed. The data were analyzed using One-way ANOVA followed by Holm-Sidak multi-comparison test (p = 0.05). Sealapex showed higher calcium peak than MTA Fillapex, GuttaFlow Bioseal, Adseal and Syntex sealers. MTA Fillapex contained a highest amount of tungstate. Sealapex presented the highest radiopacity value among the tested materials (p < 0.05), whereas MTA Fillapex was the least radiopaque material (p < 0.05). Each root canal sealer contains different compositions of radiopacifiers including bismuth oxide, calcium tungstate and zirconium oxide. The tested root canal sealers had radiopacity values above the ISO-specified limit. Sealapex was the most radiopaque root canal sealer followed by GuttaFlow Bioseal, Syntex, Adseal and MTA Fillapex.

Resumo Os cimentos endodônticos devem conter ótima adesão à dentina radicular, baixa citotoxicidade, radiopacidade suficiente e estabilidade dimensional elevada, que dependem principalmente da sua composição química. Os objetivos deste estudo foram avaliar a composição química de Syntex (Cerkamed, Stalowa Wola, Polônia), Adseal (Meta Biomed, Cheongju-si, Coreia), Sealapex (SybronEndo, Scafati, Itália), MTA Fillapex (Angelus, Londrina, Brasil) e GuttaFlow Bioseal (Coltene/Whaledent, Altstätten, Suíça) e determinar comparativamente a sua radiopacidade. Foram construídos moldes de aço inoxidável com um diâmetro interior de 5 mm e uma profundidade de 2 mm. Os cimentos testados foram misturados e vertidos em moldes. Após a fixação, foram feitas radiografias periapicais digitais dos espécimes (n=12) em condições de exposição padrão e os valores médios de cinza dos espécimes foram medidos utilizando um programa de computação gráfica. Em seguida, as amostras foram examinadas por microscopia eletrônica de varredura, e foi realizada uma análise de raios X dispersiva de energia. Os dados foram analisados utilizando a ANOVA unidirecional seguida do teste de comparação múltipla Holm-Sidak (p = 0,05). O Sealapex mostrou um pico de cálcio mais elevado do que os cimentos MTA Fillapex, GuttaFlow Bioseal, Adseal e Syntex. O MTA Fillapex continha uma quantidade mais elevada de tungstato. O Sealapex apresentou o maior valor de radiopacidade entre os materiais testados (p < 0,05), enquanto que a MTA Fillapex foi o material menos radiopaco (p < 0,05). Cada cimento endodôntico contém diferentes composições de radiopacificadores incluindo óxido de bismuto, tungstato de cálcio e óxido de zircônio. Os cimentos testados apresentaram valores de radiopacidade acima do limite especificado pela ISO. Sealapex foi o cimento obturador mais radiopaco seguido por GuttaFlow Bioseal, Syntex, Adseal e MTA Fillapex.

Antimicrobial Activity of Bioceramic Root Canal Sealers: A Systematic Review

ABSTRACT: Actually, bioceramic endodontic sealers represent an advantageous option for root canals sealing due to their multiple properties. There are several in vitro studies about their antimicrobial properties, however, their comparative antimicrobial potential, compared with other types of endodontic sealers is not entirely clear. The aim of the present research was to perform a systematic review to assess the antimicrobial effectiveness of commercially available bioceramic root canal sealers against Enterococcus faecalis in accordance with the PRISMA statement. A literature search was made in four electronic databases: MEDLINE, ClinicalKey, ScienceDirect and EBSCO. Were included in vitro studies, published in English, between 2015 and 2019. The evaluation of the selected studies was performed by two authors, independently. Four studies were included in the review. EndoSequence™ (Brasseler USA, Savannah, GA) also available on the market as TotalFill™ (Brasseler USA, Savannah, GA) and BioRoot™ were the bioceramic root canal sealers evaluated. The risk of bias was assessed according to the modified CONSORT checklist for preclinical studies. Selected studies reported positive antimicrobial activity against Enterococ cus faecalis in the bioceramic sealers evaluated. The less activity was observed on BioRoot™ sealer. All studies used a planktonic form of Enterococcus faecalis and in vitro laboratory methods of evaluation. The antimicrobial activity reported varies accordi ng to the laboratory method used, even for the same sealer, so the existence of false negatives is suggested. This systematic review identified the need for more research into the antimicrobial activity of bioceramic sealers, ideally with models using bacterial biofilms and studies in humans.

RESUMEN: En la actualidad, los cementos selladores biocerámicos son una opción ventajosa para la obturación de canales radiculares debido a sus múltiples propiedades. Existen varios estudios in vitro acerca de sus propiedades antimicrobianas, sin embargo, su potencial antimicrobiano, en comparación con otros tipos de cementos selladores endodónticos, no se está completamente claro. El propósito de la presente investigación fue realizar una revisión sistemática sobre las propiedades antimicrobianas de los cementos selladores biocerámicos disponibles en el mercado sobre Enterococcus faecalis, de acuerdo a la declaración PRIS- MA. Se realizó una búsqueda bibliográfica en cuatro bases de datos electrónicas: MEDLINE, ClinicalKey, ScienceDirect y EBSCO. Se incluyeron estudios in vitro, publicados en inglés, entre 2015 y 2019. La evaluación de los estudios seleccionados fue realizada por dos autores de forma independiente. Fueron incluidos cuatro estudios en la revisión. EndoSequence™ (Brasseler USA, Savannah, GA), también comercializado en el mercado como TotalFill™ (Brasseler USA, Savannah, GA), y BioRoot™ fueron los cementos selladores biocerámicos evaluados. El riesgo de sesgo se evaluó de acuerdo con la lista de verificación CONSORT modificada para estudios preclínicos. Los estudios seleccionados informaron actividadantimicrobiana positiva contra E. faecalis en los selladores biocerámicos evaluados. La menor actividad la presentó BioRootTM. Todos los estudios utilizaron una forma planctónica de E. faecalis y métodos de evaluación in vitro. La actividad antimicrobiana reportada varió en base al método de laboratorio utilizado, incluso para el mismo sellador, por lo que se sugiere la existencia de falsos negativos. Esta revisión sistemática identificó la necesidad de realizar más investigaciones sobre la actividad antimicrobiana de los selladores biocerámicos, idealmente con modelos que utilicen biopelículas bacterianas y estudios en humanos.

Micro-push-out bond strength of mineral­based root canal sealer in canals with different tapers / Fuerza de unión por micro-expulsión del sellador de conductos radiculares a base de minerales en conductos con diferentes ahusamientos

Objective: The aim of this study was to assess the micro-push-out bond strength of a mineral-based root canal sealer, BioRoot RCS in canals prepared by K3XF rotary systems of two different tapers. Material and Methods: Eighty caries free maxillary central incisors were used in this study. The samples were allocated into 4 groups (n=20) according to the root canal sealer and taper of the rotary instruments. The samples were obturated using single cone obturation technique. From each root 1mm thick slices at coronal, middle and apical thirds were collected using hard tissue microtome under continuous water coolant. Push-out tests were done for these sections using a Universal testing machine (INSTRON 8801) at a crosshead speed of 1mm/min. One-way analysis of variance (ANOVA) was used to compare the bond strengths within groups and Tukey's multiple post hoc analysis was used for pair-wise comparison of bond strengths. Results: AH Plus exhibited higher micro-push-out bond strength than BioRootRCS though they did not differ significantly (p>0.05). Preparation of root canals with 6% taper rotary instruments showed higher bond strength than 4% though they did not differ significantly (p>0.05). Conclusion: There was no significant difference between micro-push-out bond strength values of BioRoot RCS and AH Plus. The bond strength values were high in 6% taper canals than 4% canals though the difference was not significant statistically.

Objetivo: El objetivo de este estudio fue evaluar la fuerza de unión por micro-expulsión de un sellador de conductos radiculares de base mineral, BioRoot RCS, en conductos preparados por sistemas rotativos K3XF con dos conos diferentes. Material y Métodos: En este estudio se utilizaron 80 incisivos centrales superiores libres de caries. Las muestras se distribuyeron en cuatro grupos (n = 20) de acuerdo al sellador del conducto radicular y al cono de los instrumentos rotativos. Las muestras se obturaron mediante la técnica de obturación de un solo cono. De cada raíz se recogieron rodajas de 1 mm de grosor en los tercios coronal, medio y apical utilizando un micrótomo de tejido duro con refrigeración continua por agua. Posteriormente, se realizó una prueba de expulsión para estas secciones utilizando una máquina de prueba universal (INSTRON 8801) a una velocidad del cabezal transversal de 1mm/min. Se utilizó el análisis de varianza unidireccional (ANOVA) para comparar las resistencias de la unión dentro de los grupos y el análisis post hoc multiple de Tukey se utilizó para la comparación por pares de las resistencias de la unión. Resultados: AH Plus exhibió una fuerza de unión de micro-expulsión más alta que BioRootRCS, aunque no difirieron significativamente (p>0,05). La preparación de los conductos radiculares con instrumentos rotativos ahusados al 6% mostró una fuerza de unión superior al 4%, aunque no difirieron significativamente (p>0,05). Conclusión: No hubo diferencias significativas entre los valores de fuerza de unión de micro-expulsión de BioRoot RCS y AH Plus. Los valores de la fuerza de unión fueron más altos en canales cónicos al 6% que en canales al 4%, aunque la diferencia no fue significativa estadísticamente.

Biological properties of experimental methacrylate-based sealers containing calcium phosphates

Abstract This study aimed to evaluate, in vitro and in vivo, the biocompatibility of experimental methacrylate-based endodontic sealers containing α-tricalcium phosphate (α-TCP) or nanostructured hydroxyapatite (HAp). Experimental methacrylate-based dual-cure sealers with the addition of α-TCP or HAp, at 10%wt were formulated and compared to AH Plus (AHP). Cell viability was assessed by 3-(4,5-dimethyl-thiazoyl)-2,5-diphenyl-tetrazolium bromide (MTT), and sulforhodamine B (SRB). Sealers were implanted in rats' subcutaneous tissue and histologically evaluated. Bioactivity was assessed by alkaline phosphatase enzyme activity (ALP) and Alizarin Red (AR), using apical papillary cells (SCAPs), and by the bone deposition measured in surgical cavities on rats' femur filled with AH Plus or α-TCP. In both viability assays, HAp and AHP sealers were similar, and α-TCP presented lower viability compared to the others at MTT assay (p<0.05). A gradual decrease of the inflammatory response according to the periods was observed and AHP was the only that presented giant cells (7-day period). Collagen fibers condensation increased according to the periods, with no differences among sealers. There was an increase at ALP activity and mineralized nodules deposition according to periods. HAp and α-TCP presented higher values for ALP activity at 5 days and at 5, 10, and 15 days for AR and were different from AHP (p<0.05). α-TCP presented superior values at 10 and 15 days compared to HAp and AHP for AR (p<0.05). At 90 days, α-TCP and control (empty cavity) showed high bone deposition compared to AHP (p<0.05). α-TCP and HAp, in a methacrylate-based sealer, presented biocompatibility and bioactivity, with the potential to be used as endodontic sealers in clinical practice. Further investigations are required to gain information on the physicochemical properties of these sealers formulation before its clinical implementation.

Resumo O objetivo deste estudo foi avaliar a biocompatibilidade de cimentos endodônticos experimentais à base de metacrilato contendo fosfato α-tricálcico ou hidroxiapatita nanoestruturada in vitro e in vivo. Cimentos experimentais de cura dual à base de metacrilato com a adição de fosfato de α-tricálcico (α-TCP) ou hidroxiapatita (HAp), a 10% em peso, foram formulados e comparados com AH Plus (AHP). Viabilidade celular foi avaliada por brometo de 3- (4,5-dimetil-tiazoil) -2,5-difenil-tetrazólio (MTT) e sulforodamina B (SRB). Cimentos foram implantados no tecido subcutâneo dos ratos e avaliados histologicamente. Bioatividade foi avaliada pela atividade da enzima fosfatase alcalina (ALP) e Alizarin Red (AR) utilizando células da papila apical (SCAPs) e pela deposição óssea, medida em cavidades cirúrgicas no fêmur de ratos preenchidos com AH Plus e α-TCP. Nos dois ensaios de viabilidade, HAp e AHP não apresentaram diferenças estatísticas, α-TCP apresentou menores resultados de viabilidade para o ensaio MTT (p <0,05). Resultados histológicos mostraram que houve uma diminuição do conteúdo inflamatório de acordo com os períodos, e o AHP foi o único grupo que apresentou células gigantes (período de 7 dias). A condensação das fibras colágenas aumentou conforme os períodos, sem diferenças entre os grupos. Houve aumento da atividade da ALP e deposição de nódulos mineralizados de acordo com os períodos. HAp e α-TCP apresentaram maiores valores para a atividade de ALP em 5 dias e em 5, 10 e 15 dias para AR, com diferença para o AHP (p <0,05). O α-TCP apresentou valores superiores aos 10 e 15 dias quando comparado ao HAp e AHP para AR (p <0,05). Aos 90 dias, α-TCP e controle (cavidade vazia) apresentaram maior deposição de tecido ósseo quando comparado ao AHP (p <0,05). α-TCP e HAp, presentes nos cimentos à base de metacrilato, apresentaram biocompatibilidade e potencial para serem utilizados como seladores endodônticos na prática clínica. Investigações adicionais são necessárias para obter informações sobre as propriedades físico-químicas dessas formulações de cimentos antes de sua implementação clínica.

Influence of Powder-to-Gel Ratio on Physicochemical Properties of a Calcium Silicate Sealer / Influencia de la relación polvo-gel sobre las propiedades fisicoquímicas de un sellador de silicato de calcio

Abstract Differences in liquid-to-powder ratio can affect the properties of calcium silicate-based materials. This study assessed the influence of powder-to-gel ratio on physicochemical properties of NeoMTA Plus. Setting time (minutes), flow (mm and mm²), pH (at different periods), radiopacity (mm Al) and solubility (% mass loss) were evaluated using the consistencies for root repair material (NMTAP-RP; 3 scoops of powder to 2 drops of gel) and root canal sealer (NMTAP-SE; 3 scoops of powder to 3 drops of gel), in comparison to Biodentine cement (BIO) and TotalFill BC sealer (TFBC). Statistical analysis was performed using one-way ANOVA and Tukey tests (α=0.05). BIO had the shortest setting time, followed by NMTAP-RP and NMTAP-SE. TFBC showed the highest setting time and radiopacity. BIO, NMTAP-RP, and NMTAP-SE had similar radiopacity. All materials promoted an alkaline pH. NMTAP-RP/SE presented lower solubility than BIO and TFBC. Regarding the flow, TFBC had the highest values, followed by NMTAP-SE, and NMTAP-RP. BIO had the lowest flow. In conclusion, NMTAP in both powder-to-gel ratios showed high pH and low solubility. The increase in the powder ratio decreased the setting time and flow. These findings are important regarding the proper consistency and work time to clinical application.

Resumen Las diferencias en la proporción líquido/polvo pueden afectar las propiedades de los materiales a base de silicato de calcio. Este estudio evaluó la influencia de la proporción polvo/gel en las propiedades fisicoquímicas del cemento NeoMTA Plus. El tiempo de fraguado (minutos), la fluidez (mm y mm²), el pH (en diferentes períodos), la radiopacidad (mmAl) y la solubilidad (% de pérdida de masa) fueron evaluados utilizando las consistencias para el material de reparación radicular (NMTAP-RP; 3 cucharadas de polvo/2 gotas de gel) y para cemento sellador del conducto radicular (NMTAP-SE; 3 cucharadas de polvo/3 gotas de gel), en comparación con el cemento Biodentine (BIO) y el cemento TotalFill BC (TFBC). El análisis estadístico se realizó utilizando las pruebas ANOVA y Tukey unidireccionales (α=0.05). BIO tuvo el tiempo de fraguado más corto, seguido de NMTAP-RP y NMTAP-SE. TFBC mostró el mayor tiempo de fraguado y radiopacidad. BIO, NMTAP-RP y NMTAP-SE tuvieron una radiopacidad similar. Todos los materiales promovieron un pH alcalino. NMTAP-RP/ SE tuvieron una solubilidad menor que BIO y TFBC. Con respecto a la fluidez, TFBC tuvo los valores más altos, seguido de NMTAP-SE y NMTAP-RP. BIO tuvo la fluidez más baja. En conclusión, NMTAP en la relación polvo/gel mostró un pH alto y una baja solubilidad. El aumento en la proporción de polvo disminuyó el tiempo de fraguado y la fluidez. Estos hallazgos son importantes con respecto a su consistencia y tiempo de trabajo durante la aplicación clínica.

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.

Physicochemical properties of two epoxy resin-based sealants: Topseal® and AdSeal™. A comparative study / Propiedades físico-químicas de dos selladores a base de resina epóxica: Topseal® y AdSeal™. Estudio comparativo

Abstract Introduction: a new epoxy resin-based root-canal sealer (AdSeal™) recently appeared on the market. The aim of this study was to evaluate the radiopacity, flow rate, and film thickness of this sealant compared to Topseal®. Methods: the tests were conducted in compliance with ISO 6876:2012 standards. To evaluate radiopacity, 5 discs of each sealant measuring 10 mm in diameter by 1 mm thick were crafted, comparing their radiographic density in mm of aluminum (Al). For flow rate analysis, 0.05 ml of sealant were placed between 2 glass plates under a weight of 120 g for 10 minutes. The diameters of the formed discs were measured with a calibrator and analyzed with the imageJ software. For film thickness analysis, the sealants were placed between 2 glass plates, applying a load of 150N with a universal testing machine (AGIS 5KN) for 10 minutes. Distance between the glass plates was measured using a stereomicroscope at three equidistant points. Results: Topseal® showed more radiopacity (Wilcoxon p < 0.05) and less flow rate than AdSeal™, with statistically significant differences (Anova p = 0.0001863). The film thickness values are above the limit allowed by standard 6876, possibly because of the methodology used in this study; however, no statistically significant difference was found between the sealants (Anova p = 0.4927). Conclusions: the radiopacity and flow rate of AdSeal™ and Topseal® sealants comply with the ISO 6876:2012 standard, but the film thickness values fail to meet the standard.

Resumen Introducción: un nuevo sellador de conductos radiculares a base de resina epóxica (AdSeal™) apareció recientemente en el mercado. El objetivo de este estudio consistió en evaluar la radiopacidad, fluidez y espesor de película de este sellador comparado con el Topseal®. Métodos: las pruebas fueron realizadas en concordancia con la norma ISO 6876:2012. Para evaluar la radiopacidad se elaboraron 5 discos de cada sellador de 10 mm de diámetro por 1 mm de espesor, comparando su densidad radiográfica en mm de aluminio (Al). Para el análisis de fluidez se colocaron 0,05 ml de sellador entre 2 placas de vidrio bajo un peso de 120 g por 10 minutos; los diámetros de los discos formados se midieron con un calibrador y fueron analizados con el software imageJ. Para el análisis de espesor de película los selladores se colocaron entre 2 placas de vidrio, se aplicó una carga de 150 N con una máquina universal de ensayos (AGIS 5KN) por 10 minutos, y la distancia entre las placas de vidrio fue medida con ayuda de un estereomicroscopio en tres puntos equidistantes. Resultados: el Topseal® tuvo mayor radiopacidad (Wilcoxon p < 0,05) y menor fluidez que el AdSeal™ con diferencias estadísticamente significativas (Anova p = 0,0001863). Los valores de espesor de película están por encima del límite permitido por la norma 6876, posiblemente por la metodología utilizada en el estudio; sin embargo, no se encontró diferencia estadísticamente significativa entre los selladores (Anova p = 0,4927). Conclusiones: la radiopacidad y fluidez de los selladores AdSeal™ y Topseal® cumplen con la Norma ISO 6876:2012, pero los valores de espesor de película no cumplen con la norma.

A micro-computed tomographic study of remaining filling materials of two bioceramic sealers and epoxy resin sealer after retreatment

OBJECTIVE: This study evaluated the presence of residual root canal filling material after retreatment using micro-computed tomography (micro-CT). MATERIALS AND METHODS: Extracted human teeth (single- and double-rooted, n = 21/each; C-shaped, n = 15) were prepared with ProFile and randomly assigned to three subgroups for obturation with gutta-percha and three different sealers (EndoSeal MTA, EndoSequence BC sealer, and AH Plus). After 10 days, the filling material was removed and the root canals were instrumented one size up from the previous master apical file size. The teeth were scanned using micro-CT before and after retreatment. The percentage of remaining filling material after retreatment was calculated at the coronal, middle, and apical thirds. Data were analyzed using the Kruskal-Wallis test and Mann-Whitney U test with Bonferroni post hoc correction. RESULTS: The tested sealers showed no significant differences in the percentage of remaining filling material in single- and double-rooted teeth, although EndoSeal MTA showed the highest value in C-shaped roots (p < 0.05). The percentage of remaining filling material of AH Plus and EndoSeal MTA was significantly higher in C-shaped roots than in single- or double-roots (p < 0.05), while that of BC sealer was similar across all root types. EndoSeal MTA showed the highest values at the apical thirds of single- and double-roots (p < 0.05); otherwise, no significant differences were observed among the coronal, middle, and apical thirds. CONCLUSIONS: Within the limitations of this study, a large amount of EndoSeal MTA remained after retreatment, especially in C-shaped root canals.

Antibacterial effectiveness of calcium silicate-based root canal sealer against Enterococcus faecalis biofilms in infected dentinal tubules in vitro / 中华口腔医学杂志

Objective@#To evaluate the antiseptic effect of combined using of 5% sodium hypochlorite and calcium silicate-based root canal sealer against Enterococcus faecalis (Ef) biofilms in infected dentinal tubules in vitro.@*Methods@#Cells of Ef were inoculated into the dentinal tubules of single-rooted teeth (without caries, periapical lesions and malformations extracted due to periodontal disease or orthodontic reasons; collected from Department of Maxillofacial Surgery, The First Affiliated Hospital of Zhengzhou University) with centrifugation and incubated in brain-heart infusion (BHI) to form 3-week-old biofilms. The infected samples were subjected to sodium hypochlorite or sterile water bathing for 10 minutes followed by calcium silicate-based root canal sealer (iRoot SP) (calcium silicate-based group), Gutta-percha group and sterile water group placed on the root canal wall for 1, 4 and 12 weeks. There were two samples in each treatment at each point. The antiseptic effectiveness of combined use of sodium hypochlorite and calcium silicate-based root canal sealer was analyzed by laser scanning confocal microscope (LSCM), ANOVA and LSD-t test.@*Results@#After treatment with 5% sodium hypochlorite, in calcium silicate-based group for 4 and 12 weeks more Ef biofilm cells [(75.3±3.5)% and (74.8±3.8)%] were killed than in Gutta-percha group [(65.9±4.1)% and (63.0±3.7)%] and sterile water group [(63.9±4.0)% and (64.2±3.5)%] (P<0.05). After being treated with sterile water, the proportion of dead bacterial cells in calcium silicate-based group for 1, 4 and 12 weeks [(27.5±4.6)%, (43.0±4.4)% and (40.3±6.1)%] were more than those in Gutta-percha group and sterile water group (P<0.05). After being treated with 5% sodium hypochlorite or sterile water, more biofilm bacteria were killed in calcium silicate-based group for 4 and 12 weeks than in calcium silicate-based group for 1 week (P<0.05).@*Conclusions@#The combined use of sodium hypochlorite and calcium silicate-based root canal sealer kills more biofilm cells in infected dentinal tubules.

Effects of various root canal sealers on tooth discoloration and internal bleaching / 대한치과재료학회지

There are several causes of tooth discoloration following root canal treatment. In this study, we evaluated the effects of sealers on tooth discoloration and internal bleaching. Twenty-four teeth were divided into 4 groups: control group, AH plus, Endosequece BC, and MTA fillapex group. Root canal filling was performed using each sealer conventionally and non-vital bleaching was performed with sodium perborate. The L, a, and b values were measured using Vita easyshade. Tooth discoloration after root canal treatment occurs irrespective of the type of sealers and may cause discoloration with only gutta-percha cone. The effect of non-vital bleaching following the use of calcium silicate-based sealers such as Endosequece BC and MTA fillapex was higher than that of AH plus. Therefore, it needs careful use of sealers in endodontics and calcium silicate-based sealers have advantages of bleaching in case of discolored tooth.

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.

Pentaerythritol Tetrasalicylate in the Chemical Composition of Root Canal Sealers

Abstract The aim of this study was to synthesize and evaluate physicochemical properties of a new salicylate derivative in experimental calcium-based root canal sealers. Two salicylate derivatives were synthesized for the transesterification reaction of methyl salicylate with two different alcohols (1,3-butylenoglicol disalicylate-BD and pentaerythritol tetrasalicylate -PT) in molar ratio 1:3 and 1:6, respectively. The products (BD and PT), were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance spectroscopy (RMN). Calcium-based experimental sealers were prepared with the same catalyst paste (60% of MTA, 39% of n-ethyl-o-toluenesulfonamide, and 1% titanium dioxide) and four different concentrations of BD and PT in the base pastes (40/0 - control, 35/5, 30/10 and 20/20) with 60% of bismuth oxide. The experimental sealers were evaluated for setting time, solubility (24 h, 7, 14 and 30 days), diametral tensile strength and Young's Modulus. Data were analyzed by one- or two-way ANOVA with Tukey's test (p<0.05). The addition of PT reduced the materials setting time. After 24 h the sealer 40/0 and 35/5 had higher solubility, and after 14 and 28 days the sealer 20/20 showed the lowest solubility (p<0.05). After 7 days the sealer 20/20 stabilized its solubility. The sealer 40/0 presented the highest values and the 20/20 presented the lowest values of diametral tensile strength and Young's modulus (p<0.05). The addition of PT to calcium-based root canal sealers provides benefits to the setting time and solubility.

Resumo O objetivo neste estudo foi sintetizar e avaliar as propriedades físico-químicas de um novo derivado do salicilato em cimentos endodônticos experimentais à base de cálcio. Dois derivados de salicilato foram sintetizados por meio de uma reação de trans esterificação do salicilato de metila com dois diferentes alcoóis (1,3-butilenoglicol dissalicilato-BD e pentaeritritol tetrassalicilato-PT) na proporção molar de 1: 3 e 1:6, respectivamente. Os produtos (BD e PT), foram caracterizados por espectroscopia infravermelho transformada de Fourier (FTIR) e espectroscopia de ressonância magnética nuclear (RMN). Os cimentos experimentais à base de cálcio foram preparados com a mesma pasta catalisadora (60% de MTA, 39% de N-etil o/p toluenosulfonamida e 1% de dióxido de titânio) e quatro concentrações diferentes de BD e PT nas pastas base (40/0 - controle, 35/5, 30/10 e 20/20) com 60% de óxido de bismuto. Os cimentos foram avaliados quanto ao tempo de endurecimento, à solubilidade (24 h, 7, 14 e 28 dias), resistência à tração diametral e ao módulo de elasticidade. Os dados foram analisados por ANOVA um ou dois fatores e as médias comparadas pelo teste de Tukey (p<0,05). A adição de PT reduziu o tempo de endurecimento dos materiais testados. Após 24 horas os cimentos 40/0 e 35/5 apresentaram maior solubilidade que os demais e após 14 e 28 dias o cimento 20/20 foi o que apresentou menor solubilidade (p<0,05). Após 7 dias o grupo 20/20 estabilizou a sua solubilidade. O cimento 40/0 apresentou os maiores valores e o cimento 20/20 apresentou os menores valores de resistência à tração diametral e módulo de elasticidade (p<0,05). A adição de PT a cimentos à base de cálcio possibilita benefícios ao tempo de presa e solubilidade.

Bacterial leakage and micro-computed tomography evaluation in round-shaped canals obturated with bioceramic cone and sealer using matched single cone technique

OBJECTIVES: To evaluate sealing ability of root canals obturated with bioceramic-impregnated gutta percha cone (BCC) or gutta percha (GP), with bioceramic sealer (BCS) or AH Plus (AH; Dentsply-Maillefer), in roundly-prepared canals using matched single-cone technique, based on bacterial leakage test, and to analyze obturation quality using micro-computed tomography (CT) analysis. MATERIALS AND METHODS: Ninety-two distobuccal roots of maxillary molars were prepared using nickel-titanium files to apical size 40/0.06. The roots were divided into 4 groups (n = 20) that were obturated with a master cone and sealer: GP/AH, BCC/AH, GP/BCS, and BCC/BCS. Bacterial leakage model using Enterococcus faecalis was used to evaluate sealing ability for 60-day period. Obturated samples from each group (n = 4) were analyzed using micro-CT. RESULTS: All groups showed bacterial leakage at 20%–45% of samples with mean leakage times of 42–52 days. There were no significant differences in bacterial leakage among the groups. Micro-CT showed minimal gaps and voids in all groups at less than 1%. CONCLUSIONS: In roundly-prepared canals, the single cone obturation with BCC/BCS was comparable to GP/AH for bacterial leakage at 60 days.

The effect of different final intracanal irrigants on the bond strength of silicone-based sealer to root canal walls / 天津医药

Objective To evaluate the bond strength of GuttaFlow sealers to root canal walls after final rinse with two novel fi nal irrigation regimens, QMiX and 17%EDTA+0.2%Cetrimide (CTR). Methods Thirty single-canal teeth were prepared chemomechanically using 5.25% sodium hypochlorite (NaOCl) as root canal irrigants. The teeth were then randomly distributed into three groups(n=10)according to the final irrigation protocol:QMiX group,17% EDTA followed by CTR group and control group(normal saline,NS).After the filling with GuttaFlow using a lentulo spiral,the roots were transversally sectioned to obtain 2 mm thick dentinal slices.Then a push-out bond strength test was carried out,and failure mode was determined at×24 magnification.Results The push-out bond strength was significantly higher in QMiX group than that of EDTA+CTR group and NS group(P<0.05),and no significant difference was observed between EDTA+CTR and NS groups(P>0.05).The failure patterns were mainly mixed.Conclusion The QMiX,as the final irrigant,can improve the bond strength of silicone-based sealer GuttaFlow.

Difficulties and misunderstandings of root canal filling / 华西口腔医学杂志

Root canal filling is performed as the final and most important procedure of root canal treatment. The superior 3D filling is the key determinant of endodontic success. However, such procedure remains a challenge because of the complexity of the root canal system and the limitation of root canal filling materials and methods. This paper provides an overview of current principles and practices in root canal filling, focusing on advantages, disadvantages and indications. The process errors and countermeasures in various root canal filling methods are also discussed. This review provides guidance and help for clinical and practice to achieve a satisfactory root canal filling and improve root canal treatment outcome.

The effects of different final irrigation regimens on the bond strength of sealers to root canal walls / 实用口腔医学杂志

Objective:To evaluate the bond strength of root canal sealer AH Plus and GuttaFlow to root canal walls after final rinse with 4 different final irrigation regimens.Methods:60 teeth with single-canal were prepared chemomechanically using 5.25% sodi-um hypochlorite (NaOCl)as root canal irrigant.The teeth were then randomly distributed into 3 groups(n =20)according to the final irrigation protocol:1 7% EDTA followed by 2% chlorhexidine(CHX)(group 1 ),5.25% NaOCl followed by 1 7% EDTA(group 2), 0.9% normal saline(NS)(group 3).The root canals were then filled with sealers using a lentulo spiral and each group was distribu-ted into 2 subgroups according to the sealers(n =1 0):a.AH Plus;b.GuttaFlow.The roots were transversally sectioned to obtain 2mm thick dentinal slices.Then a push-out bond strength test was carried out and failure mode was observed by stereomicroscope. Results:The bond strength of AH Plus was significantly higher than that of GuttaFlow(P 0.05).When the root canals were filled with GuttaFlow,the push-out strength of group 1 ,2 and 3 was (1 .40 ±0.59)MPa, (1 .26 ±0.62)MPa and (1 .05 ±0.27)MPa respectively(P >0.05).The failure modes of AH Plus and GuttaFlow were both mainly mixed,but the proportion of adhesive failure in the canals filled with GuttaFlow were obviously higher than AH Plus.Conclusion:The bond strength to root canal wall of GuttaFlow is significantly lower than that of AH Plus.1 7% EDTA followed by 2% CHX as fi-nal irrigant can reduce the bond strength of AH Plus but has no marked effect on GuttaFlow.