Continuous Wave of Condensation Improves the Filling of Curved Canals: a Micro-CT Study / La condensación de onda contínua mejora el selle de canales curvos: un estudio de micro-CT

Abstract The aim of this study was to compare the filling capacity in curved root canal using a new continuous wave of condensation technique (Termo Pack II, Easy Dental Equipments, Brazil) or lateral compaction. The percentage of voids in the filling of mesial root canals of mandibular molars was assessed by micro-computed tomography (micro-CT). Mesial root canals (n=24) of mandibular molars with a degree of curvature between 20° and 40° were prepared using rotary system (ProDesign Logic, Easy, Brazil) up to #35, .05 taper. The root canals were filled by using the continuous wave of condensation system or lateral compaction and AH Plus sealer (n=12). Scanning at 9 µm was performed after preparation and after filling by using micro-CT SkyScan 1176. The volumetric percentage of filling material and voids (total length and in each root canal third) were calculated. Data were analyzed using ANOVA/ Tukey and Student's t tests (α=0.05). Before the filling techniques, the root canals volume after preparation was similar (p>0.05). The root canals filled by the continuous wave of condensation technique presented the lowest percentage of voids, and the greatest percentage of filling material in total length and thirds (cervical, middle and apical) (p<0.05). Both techniques were not able of completely filling the root canals. The continuous wave of condensation technique Termo Pack II promoted better root canal filling in curved root canals, when compared with lateral compaction.

Resumen El objetivo de este estudio fue comparar la capacidad de obturación en conductos radiculares curvos utilizando una nueva técnica de condensación de onda continua (Termo Pack II, Easy Dental Equipments, Brasil) vs compactación lateral. El porcentaje de brechas en la obturación de los conductos radiculares mesiales de los molares mandibulares se evaluó mediante microtomografía computarizada (micro-CT). Se prepararon conductos radiculares mesiales (n=24) de molares mandibulares con un grado de curvatura entre 20° y 40° utilizando un sistema rotatorio (ProDesign Logic, Easy, Brasil) al #35, conicidad 0,05. Los conductos radiculares se obturaron utilizando un sistema de condensación de onda contínua o compactación lateral y cemento AH Plus (n=12). Se realizó un escaneo de 9 µm después de la preparación y después de la obturación usando el micro-CT SkyScan 1176. Se calculó el porcentaje volumétrico de material de obturación y vacíos (longitud total y en cada tercio del conducto radicular). Los datos se analizaron utilizando las pruebas ANOVA/Tukey y t de Student (α=0,05). Antes de las técnicas de obturación, el volumen de los conductos radiculares después de la preparación fue similar (p>0,05). Los conductos radiculares obturados con la técnica de condensación por onda contínua presentaron el menor porcentaje de vacíos y el mayor porcentaje de material de obturación en longitud total y en tercios (cervical, medio y apical) (p<0,05). Ambas técnicas no fueron capaces de llenar completamente los conductos radiculares. La técnica de condensación de onda contínua Termo Pack II promovió un mejor relleno del conducto radicular en conductos radiculares curvos en comparación con la compactación lateral.

Effect of Endo-Z bur or Bladesonic ultrasonic tip on the adaptation of filling material. A micro-CT study

Abstract This study aimed to evaluate the effect of apicoectomy performed with a bur or an ultrasonic tip on the adaptation of the filling material to root canal dentin. Twenty human mandibular incisors were selected and prepared with a ProDesign Logic system up to diameter 40/.05. The root canals were filled with Bio-C Sealer (Angelus, PR, Brazil) using the single cone technique and were stored at 37ºC and 95% relative humidity for 7 days. After this period, the apicoectomy of the 3 millimeters of the root apex was performed using Endo-Z bur (Dentsply Sirona) or Bladesonic ultrasonic tip (Helse Ultrasonic, Santa Rosa de Viterbo, Brazil) (n=10). The specimens were scanned by micro-computed tomography (micro-CT; SkyScan 1176) with a voxel size of 8.74 µm after obturation and after apicoectomy. The percentage of voids at the interface between the filling material and the root canal wall was evaluated in the apical 4 mm of the root after apicoectomy, besides the time cutting to both devices. The data obtained were submitted to paired and unpaired t-tests (α = 0.05). Endo-Z and Bladesonic increased the percentage of voids between the filling material and the dentin after apicectomy (p<0.05), and they were similar (p>0.05). Endo-Z has a shorter time to perform apicoectomy compared to Bladesonic (p<0.05). Apicectomies with Endo-Z or Bladesonic could harm the material/dentin interface, while the Endo-Z bur was faster than the Bladesonic ultrasonic tip.

Resumo O objetivo deste estudo foi avaliar o efeito da apicectomia realizada com broca ou inserto ultrassônico na adaptação do material obturador á dentina do canal radicular. Vinte incisivos inferiores humanos extraídos foram selecionados e preparados com o sistema ProDesign Logic até o diâmetro 40/.05. Os canais radiculares foram obturados com Bio-C Sealer (Angelus, PR, Brasil) por meio da técnica de cone único e foram armazenados em estufa a 37ºC e umidade relativa de 95% por 7 dias. Após esse período, foi realizada apicectomia dos 3 milímetros apicais utilizando broca Endo-Z (Maillefer - Dentsply) ou inserto ultrassônico BladeSonic (Helse Ultrasonic, Santa Rosa de Viterbo, Brasil) (n=10). Os espécimes foram escaneados por meio de microtomografia computadorizada (micro-CT; SkyScan 1176) com tamanho de voxel de 8,74 µm após obturação e após apicectomia. Please, correct this sentece to O percentual de falhas na interface entre o material obturador e a parede dentinaria foi avaliado nos 4 mm apicais da raiz apos apicectomia, alem do tempo de corte para ambos dispositivos. Os dados obtidos foram submetidos aos testes t pareado e não pareado (α = 0,05). Endo-Z e Bladesonic aumentaram o percentual de vazios entre o material obturador e a parede da dentina após apicectomia (p<0.05), sendo semelhantes entre si (p>0.05). Endo-Z demonstrou menor tempo para realizar apicectomia em comparação com Bladesonic (p<0.05). Apicectomias com Endo-Z ou Bladesonic podem prejudicar a interface material obturador/dentina, sendo a broca Endo-Z mais rápida que a ponta ultrassônica Bladesonic.

Effect of voxel size of Micro-CT on the assessment of root canal preparation

The aim of this study was to assess the influence of micro-computed tomography (micro-CT) voxel size on evaluation of root canal preparation using rotary heat-treated nickel-titanium files. Curved mesial root canals of mandibular molars were prepared using ProDesign Logic 30/.05 (PDL) or HyFlex EDM 25/.08 (HEDM) (n=12). The specimens were scanned using micro-CT with 5μm of voxel size before and after root canal preparation. Images with sub-resolution of 10 and 20μm voxel sizes were obtained. The percentage of volume increase, debris and uninstrumented root canal surface were analyzed in the different voxel sizes. Data were compared using unpaired Student's t-test and ANOVA statistical tests (α=0.05). No differences were observed for percentage of volume increase, debris and instrumented surface between the root canals prepared by PDL and HEDM (p>0.05). Both systems promoted higher percentage of debris in the apical third compared to the middle third (p0.05). PDL and HEDM had similar root canal preparation capacity. Micro-CT images using different voxel sizes did not influence the results of volume increase and debris evaluation. However, images at 5µm showed greater accuracy to evaluate the percentage of uninstrumented surfaces.

El objetivo de este estudio fue evaluar la influencia del tamaño de vóxel de la microtomografía computarizada (micro-CT) en la evaluación de la preparación del conducto radicular utilizando limas rotatorias de níquel-titanio tratadas térmicamente. Se prepararon conductos radiculares mesiales curvos de molares mandibulares usando ProDesign Logic 30/.05 (PDL) o HyFlex EDM 25/.08 (HEDM) (n=12). Las muestras se escanearon usando micro-CT con un tamaño de vóxel de 5μm antes y después de la preparación del conducto radicular. Se obtuvieron imágenes con subresolución de vóxeles de 10 y 20μm. Se analizó el porcentaje de aumento de volumen, residuos y superficie del conducto radicular no instrumentado en diferentes tamaños de vóxel. Los datos se compararon usando la prueba t de Student no pareada y las pruebas estadísticas ANOVA (α=0,05). No se observaron diferencias en el porcentaje de aumento de volumen, detritus y superficie instrumentada entre los conductos radiculares preparados por PDL y HEDM (p>0,05). Ambos sistemas promovieron un mayor porcentaje de detritos en el tercio apical en comparación con el tercio medio (p0,05). PDL y HEDM tenían una capacidad de preparación del conducto radicular similar. Las imágenes de micro-CT que utilizan diferentes tamaños de vóxel no influyeron en los resultados de la evaluación del volumen y los desechos. Sin embargo, las imágenes de 5µm mostraron una mayor precisión al evaluar el porcentaje de superficies no instrumentadas.

Physicochemical properties, cytotoxicity and bioactivity of a ready-to-use bioceramic repair material

Abstract The aim of this study was to evaluate the physicochemical properties, cytotoxicity and bioactivity of a ready-to-use bioceramic material, Bio-C Repair (Angelus), in comparison with White MTA (Angelus) and Biodentine (Septodont). The physicochemical properties of setting time, radiopacity, pH, solubility, dimensional and volumetric changes were evaluated. Biocompatibility and bioactivity were assessed in Saos-2 osteoblast cell cultures by the MTT assay 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), Neutral Red (NR), Alizarin Red (ARS), and cell migration tests. Statistical analysis was performed by ANOVA, Tukey or Bonferroni tests (α = 0.05). Bio-C Repair had the longest setting time (p < 0.05), but radiopacity and solubility were accordance with the ISO 6876/2012 standards, besides linear expansion. Bio-C Repair and MTA had similar volumetric change (p > 0.05); lower than Biodentine (p < 0.05). All the materials evaluated had an alkaline pH. Bio-C Repair was cytocompatible and promoted mineralized nodule deposition in 21 days and cell migration in 3 days. In conclusion, Bio-C Repair had adequate radiopacity above 3mm Al, solubility less than 3%, dimensional expansion, and low volumetric change. In addition, Bio-C Repair promoted an alkaline pH and presented bioactivity and biocompatibility similar to MTA and Biodentine, showing potential for use as a repair material.

Resumo O objetivo deste estudo foi avaliar as propriedades físico-químicas, citotoxicidade e bioatividade de um novo material biocerâmico pronto para uso, Bio-C Repair (Angelus), em comparação com MTA Branco (Angelus) e Biodentine (Septodont). Foram avaliadas as propriedades físico-químicas de tempo de presa, radiopacidade, pH, solubilidade, alterações dimensionais e volumétricas. A biocompatibilidade, bioatividade e capacidade de reparo foram avaliadas em culturas de células de osteoblastos Saos-2 pelo ensaio MTT brometo de 3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazólio), vermelho neutro (NR), vermelho de alizarina ( ARS) e testes de migração celular. A análise estatística foi realizada pelos testes ANOVA, Tukey ou Bonferroni (α = 0,05). Bio-C Repair apresentou o maior tempo de presa (p < 0,05), mas radiopacidade e solubilidade de acordo com as normas ISO 6876/2012, além de expansão linear. Bio-C Repair e MTA tiveram variação volumétrica semelhante (p > 0,05), menor que Biodentine (p < 0,05). Todos os materiais avaliados apresentaram pH alcalino. Bio-C Repair foi citocompatível, além de promover deposição de nódulos mineralizados em 21 dias e migração celular em 3 dias. Em conclusão, o Bio-C Repair apresentou radiopacidade adequada acima de 3mmAl, solubilidade menor que 3%, expansão dimensional e baixa perda volumétrica.. Além disso, o Bio-C Repair promoveu um pH alcalino e apresentou bioatividade e biocompatibilidade semelhantes ao MTA e Biodentine, mostrando potencial para uso como material reparador

How does nano-focus computed tomography impact the quantification of debris within the root canal system?

Abstract The aim of this study was to compare the quantification of hard-tissue debris by using micro-computed tomography (micro-CT) and nano-focus computed tomography (nano-CT) after root canal instrumentation. Ten mandibular molars containing an isthmus in the mesial root were scanned in a SkyScan 1172 micro-CT device with a voxel size of 12.8 µm and in a NanoTom nano-CT device with 5.5 µm. The mesial root canals were irrigated with 5 mL of saline solution at the orifice level, instrumented with Reciproc R25 files and a second scanning was performed by micro-CT and nano-CT devices for post-instrumentation images. DataViewer software was used for registering the pre- and post-operative micro-CT and nano-CT images. The root canal and the debris were segmented for quantitative analysis of the volume of the canal and volume of debris using CTAn software. Statistical analysis was performed using the T test for comparison between volume of the canal after instrumentation and volume of debris in both image modalities. The level of significance was set at p < 0.05. Nano-CT images showed higher values of debris when compared with micro-CT (p < 0.05) after root canal instrumentation. No difference was observed between the volume of the root canal after instrumentation in the two imaging methods used (p > 0.05). Nano-CT technology can be recommended as a more precise method for quantitative analysis of hard-tissue debris. Moreover, in Endodontic research it is a promising method, as it is capable of providing higher spatial and contrast resolution, faster scanning and higher image quality.

Diamond-coated ultrasonic tip decreases debris and uninstrumented surface after preparation of curved canals with isthmus

Abstract The aim of this study was to evaluate root canal preparation with nickel titanium rotary instruments and complementary preparation with ultrasonic tip in curved canals of mandibular molars with isthmus. Twenty-eight mesial roots of mandibular molars with curvature between 20° and 40° and presence of isthmus throughout the entire extension of the root canals were prepared using ProDesign Logic CM (PDL) up to size 40.05, or HyFlex EDM (HFEDM) up to size 40.04. Complementary preparation was performed in the isthmus region using the ultrasonic insert E18D (Helse, Istmo Diamantada). The root canals were scanned using micro-CT (SkyScan 1176) at 9 µm voxel size before and after each preparation step. Transportation, percentage of increase in volume, debris and uninstrumented surface (UNS) were evaluated. Mann Whitney, Wilcoxon, paired and non-paired t-tests were used for statistical analysis (α = 0.05). The canals prepared with PDL and HFEDM obtained similar results for all the variables assessed before using E18D (p > 0.05). E18D significantly decreased the percentage of debris and UNS values in both Groups (p < 0.05). The complementary preparations with E18D caused a smaller quantity of debris in the isthmus of the canals previously prepared with PDL in comparison with HFEDM (p < 0.05). PDL and HFEDM provided similar root canal preparation. PDL promoted a smaller quantity of Debris in the isthmus than HFEDM after using E18D. E18D significantly improved cleaning, and reduced Debris and UNS.

Análise de metodologias para avaliação da solubilidade do cimento à base de silicato de cálcio Bio-C Sealer / Analysis of methodologies for evaluating the solubility of calcium silicate-based sealer Bio-C Sealer

Introdução: Cimentos endodônticos à base de silicato de cálcio demonstram maior solubilidade em água destilada. Emprego de metodologias alternativas pode auxiliar em melhor compreensão sobre a solubilidade desses materiais. Objetivo: Avaliar o efeito da solução de imersão e do tipo de modelo experimental na solubilidade de cimento pronto para uso Bio-C Sealer. Material e método: Modelos circulares de polietileno ou dentina bovina (n = 16) foram confeccionados. Após inserção do cimento, os espécimes foram mantidos em estufa a 37 °C por 48 horas. Posteriormente, as amostras foram pesadas em balança de precisão para determinação da massa inicial. Na sequência, os espécimes foram imersos em 7,5 mL de água destilada (pH 6,5) ou PBS (pH 7,0) (n = 8) por 28 dias. Após isso, as amostras foram removidas das soluções e pesadas a cada 24 horas até a estabilização da massa final (0,001g). Corpos de prova confeccionados com Bio-C Sealer foram empregados como controle. A solubilidade foi avaliada de acordo com a diferença entre a massa inicial e final em porcentagem. Teste ANOVA Two-Way e teste post-hoc de Tukey foram realizados (α = 0,05). Resultado: Imersão em água destilada proporcionou maior solubilidade em comparação com PBS, independentemente do modelo experimental (p < 0,05). Corpos de prova apresentaram maior solubilidade, seguidos dos modelos de polietileno e dentina imersos em água destilada (p < 0,05). Não houve diferença entre os modelos experimentais imersos em PBS (p > 0,05). Conclusão: Bio-C Sealer apresenta solubilidade significativamente maior em água destilada do que em PBS em todas condições. Modelo experimental empregando dentina bovina e PBS como solução de imersão demonstra diminuir a perda de massa de Bio-C Sealer e pode ser uma alternativa valiosa para avaliar a solubilidade de cimentos biocerâmicos

Introduction: Calcium silicate-based sealers demonstrate greater solubility in distilled water. The use of alternative methodologies can help at better understanding the solubility of these materials. Objective: To evaluate the effect of the immersion solution and the type of experimental model on the solubility of readyto-use Bio-C Sealer. Material and method: Circular models of polyethylene or bovine dentin (n = 16) were made. After insertion of the sealer, the specimens were kept in an oven at 37°C and 95% humidity for 48h. Subsequently, the samples were weighed on a precision balance to determine the initial mass. Next, the specimens were immersed in 7.5 mL of distilled water (pH 6.5) or PBS (pH 7.0) (n = 8) for 28 days. After that, the samples were removed from the solutions and weighed every 24 hours until the final mass stabilized (0.001g). Test specimens made with Bio-C Sealer were used as a control. Solubility was evaluated according to the difference between the initial and final mass in percentage. Two-Way ANOVA test and Tukey post-hoc tests were performed (α=0.05). Result: Immersion in distilled water provided greater solubility compared to PBS regardless of the experimental model (p<0.05). The test specimens showed greater solubility, followed by polyethylene and dentin models immersed in distilled water (p<0.05). There was no difference between the experimental models immersed in PBS (p>0.05). Conclusion: Bio-C Sealer presents significantly greater solubility in distilled water than in PBS under all conditions. Experimental model using bovine dentin and PBS as an immersion solution demonstrates reduction in the mass loss of Bio-C Sealer and can be a valuable alternative for evaluating the solubility of bioceramic sealers

A new proposal for evaluating of the solubility of bioceramic materials in dentin tubes after immersion in PBS: a laboratory investigation / Nova proposta para avaliação da solubilidade de materiais biocerâmicos em tubos de dentina após imersão em PBS: um estudo laboratorial

Introdução: Materiais reparadores devem apresentar baixa solubilidade. Solução salina tamponada com fosfato (PBS) permite simular condição clínica e interação com dentina pode ser importante para correta avaliação da perda de massa de cimentos biocerâmicos. Objetivo: Avaliou o efeito da imersão em água destilada (AD) ou PBS na solubilidade de Bio-C Repair (BCR, Angelus) ou MTA Repair HP (MTAHP, Angelus) usando modelo de tubo de dentina. Material e método: Tubos de dentina bovina foram confeccionados com 4 mm de comprimento, 1,5 mm de diâmetro interno e 1 mm aproximadamente de espessura de parede. Os espécimes foram imersos em AD por 24h, posteriormente preenchidos com BCR ou MTAHP (n = 14) e armazenados em estufa a 37°C e umidade 95% por 24h. Após serem pesados em balança de precisão para determinação da massa inicial, os corpos de prova foram imersos em AD (pH 6,5) ou PBS (pH 7,0) (n = 7) por 28 dias. Tubos vazios também foram utilizados para o cálculo de perda de massa da dentina (n=4). Após esse período, os espécimes foram pesados até a estabilização da massa final (0,001g). A solubilidade de cada material foi avaliada. Testes estatísticos ANOVA e Tukey foram realizados (α=0,05). Resultado: BCR e MTAHP apresentaram ganho de massa em AD e perda de massa em PBS (p<0,05). Conclusão: A solução de imersão influencia a solubilidade de BCR e MTAHP usando modelo de tubo de dentina. Nova proposta metodológica poderá ser uma alternativa às normas ISO para testar a solubilidade de cimentos biocerâmicos

Introduction: Repair materials must have low solubility. Phosphate buffered saline (PBS) allows simulating clinical condition and interaction with dentin may be important for the correct evaluate of mass loss of bioceramic cements. Objective: To evaluate the effect of distilled water (DW), or PBS immersion on the solubility of Bio-C Repair (BCR, Angelus) or MTA Repair HP (MTAHP, Angelus) using a dentin tube model. Material and method: Bovine dentin tubes with a length of 4 mm, an internal diameter of 1.5 mm and walls thickness of approximately 1 mm were made. The specimens were immersed in DW for 24h, then filled with BCR or MTAHP (n = 14) and stored in an oven at 37°C and 95% humidity for 24h. After being weighed on a precision balance to determine the initial mass, the specimens were immersed in DW (pH 6.5) or PBS (pH 7.0) (n = 7) for 28 days. Empty tubes also were used for calculating the mass loss of the dentin (n=4). After this period, the specimens were weighed until stabilization of the final mass occurred (0.001g). The solubility of each material was evaluated. ANOVA and Tukey statistical tests were performed (α=0.05). Result: BCR and MTAHP showing gain of mass in DW and mass loss in PBS (p<0.05). Conclusion: The immersion solution influenced the solubility of BCR and MTAHP using dentin tube model. The new methodological proposal could be an alternative to ISO standards for testing the solubility of bioceramic cement

Physicochemical Properties and Antibiofilm Activity of Tricalcium Silicate Cement and its Association with Cetrimide / Propiedades físico-químicas y actividad antibiofilm del cemento de silicato tricálcico y su asociación con cetrimida

Abstract Cetrimide (CTR) is a cationic surfactant detergent with antimicrobial and antibiofilm activity. The aim of this study was to evaluate setting time, pH, solubility and antibiofilm activity of tricalcium silicate cement (TSC) with zirconium oxide (ZrO2) and its association with 0.2 and 0.4% cetrimide. Initial and final setting times (IST and FST) were assessed based on ISO-6876. pH was evaluated at periods of 1,3,7,14 and 21 days. Solubility was analyzed by weight loss. A modified direct contact test (MDCT) on the biofilm of Enterococcus faecalis formed on bovine root dentin blocks was performed, after 6 hours of manipulation and 15 hours of contact time. The analysis was performed by UFC mL ¯¹ counting. The data were analyzed by ANOVA and Tukey's tests (α=0.05). Higher IST was observed for TSC/ZrO2+CTR in both concentrations than for TSC/ZrO2 and lower FST for TSC/ZrO2+0.4% CTR (p0.05). All materials exhibited increased mass. TSC/ZrO2+CTR 0.4% had lower mass gain than the other materials (p<0.05). The highest antibiofilm activity was observed for TSC/ZrO2+CTR in both concentrations, when compared with the positive control (p<0.05). In conclusion, CTR exhibited potential to promote greater antibiofilm activity to tricalcium silicate cement, without harming its physicochemical properties of setting time, pH and solubility.

Resumen Cetrimida (CTR) es un detergente y surfactante catiónico con actividad antimicrobiana y antibiofilm. El objetivo de este estudio fue evaluar el tiempo de fraguado, pH, solubilidad y actividad antibiofilm del cemento de silicato tricálcico (CST) con óxido de zirconio (ZrO2) y su asociación con CTR a 0.2% y 0.4%. Tiempo de fraguado inicial y final (TFI y TFF) fueron determinados con base en las normas ISO-6876. pH fue evaluado en los períodos de 1,3, 7,14 y 21 días. Solubilidad fue analizada por la pérdida de masa/peso. El test de contacto directo modificado (TCDM) fue realizado sobre biofilm de Enterococcus faecalis formado en dentina radicular bovina, después de 6 horas de manipulación de los cementos y 15 horas de contacto. El análisis fue realizado por la cuantificación de UFC mL¯¹. Los datos fueron analizados usando las pruebas de ANOVA y Tukey (α=0.05). Mayor TFI fue observado para CST/ ZrO2+CTR en las dos concentraciones que para TSC/ZrO2 y menor TFF para TSC/ ZrO2+CTR 0.4% (p0.05). Todos los materiales mostraron aumento de masa. TSC/ZrO2+CTR 0.4% tuvo menor gano de masa que los otros materiales (p<0.05). Mayor actividad antibiofilm fue observado para CST/ZrO2+CTR en las dos concentraciones, cuando comparados con el grupo control positivo (p<0.05). En conclusión, CTR demostró potencial para promover superior actividad antibiofilm al cemento de silicato tricálcico (CST), sin perjudicar sus propiedades físico-químicas de tiempo de fraguado, pH y solubilidad.

Evaluation of in vitro experimental model for analysis of bioceramic sealers

Abstract This study aimed to evaluate physicochemical properties of three ready-to-use calcium silicate-based endodontic sealers: Endosequence BC Sealer, Bio C Sealer, and Sealer Plus BC. Radiopacity was evaluated using specimens of 10 mm in diameter and 1 mm in height, along with an aluminum step wedge. For the flow test, 0.5 mL of each sealer was deposited between glass plates and the mean of the measurement of two diameters was considered the cement flow value. For pH and calcium release, root canals of 30 prototypes of upper incisor acrylic resin teeth were filled with sealer and gutta percha point and then immersed in containers with 13 mL of ultrapure water. Both pH and release of calcium ions (atomic absorption spectrophotometer) were measured at 3, 24, 72, and 168 h. Acrylic resin teeth were scanned by Micro-CT 1174 at the time of pH and calcium ion readings for volumetric change analysis. The data were analyzed by ANOVA, Tukey's, Kruskal-Wallis, and Dunn's tests. Endosequence BC Sealer presented the lowest, and Bio C Sealer the highest volumetric change after 72 h and 168 h (p < 0.05). Endosequence BC Sealer presented higher radiopacity (p < 0.05). All materials showed alkalinization capacity. All of them presented calcium ion release, with a higher value for Sealer Plus BC. All materials presented alkalinization, calcium release capacity, radiopacity, and flow above the minimum values required by the ISO standard. The highest volumetric loss was experienced by Bio C Sealer and the lowest one by Endosequence BC Sealer.

Cytotoxicity and bioactive potential of new root repair materials for use with BMP-2 transfected human osteoblast cells

Abstract: Modified formulations of calcium silicate repair materials with additives have been developed to enhance handling, consistency, biocompatibility and bioactivity. Considering the relevance of osteoblastic cell response to mineralized tissue repair, human osteoblastic cells (Saos-2 cells overexpressing BMP-2) were exposed to mineral trioxide aggregate (MTA) (with calcium tungstate - CaWO4), MTA HP Repair, Bio-C Repair and Bio-C Pulpo. Cell viability was assessed by 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) and neutral red (NR), and cell death, by flow cytometry. Gene expression of bone morphogenetic protein 2 (BMP-2), runt-related transcription factor 2 (RUNX-2), and alkaline phosphatase (ALP) osteogenic markers were evaluated by real-time polymerase chain reaction (RT-qPCR). ALP activity and alizarin red staining (ARS) were used to detect mineralization nodule deposition. Bioactive cements presented no cytotoxic effect, and did not induce apoptosis at the higher dilution (1:12). MTA, Bio-C Repair and Bio-C Pulpo exhibited higher ALP activity than the control group (P < 0.05) after 7 days. MTA, MTA HP and Bio-C Pulpo affected the formation of mineralized nodules (p < 0.05). Exposure to all cement extracts for 1 day increased BMP-2 gene expression. RUNX-2 mRNA was greater in MTA, MTA HP and Bio-C Repair. MTA, MTA HP and Bio-C Pulpo increased the ALP mRNA expression, compared with BMP-2 unexposed cells (P < 0.05). Calcium silicate cements showed osteogenic potential and biocompatibility in Saos-2 cells transfected BMP-2, and increased the mRNA expression of BMP-2, RUNX-2, and ALP osteogenic markers in the BMP-2 transfected system, thereby promoting a cellular response to undertake the mineralized tissue repair.

Physicochemical properties and osteoclastogenesis for three premixed calcium silicate-based sealers post set

Abstract: Solubility, pH, ion release, cytotoxicity, and osteoclastogenesis inhibition in bone marrow-derived monocyte macrophages (BMMs) were evaluated in EndoSequence BC Sealer (END), Bio-C Sealer (BC), and Sealer Plus BC (SPBC). pH was determined after immersion of the sealers in deionized water (DW) and Minimum Essential Medium Alpha (α-MEM). Solubility was obtained by mass loss. Ion release was measured by using X-ray fluorescence spectroscopy (XRF). Cytotoxicity was evaluated by MTT assay. Inhibition of osteoclastogenesis was evaluated by tartrate-resistant acid phosphatase (TRAP). Data were analyzed using the t-test, ANOVA and Tukey/Dunnett's post-hoc tests (α = 0.05). END had the highest pH in DW (p < 0.05), and BC, in α-MEM (p < 0.05). Solubility in DW was the lowest for SPBC (p < 0.005). The highest calcium release was observed for BC in DW at 12 h (p < 0.05), and in α-MEM at 12 and 24 h (p < 0.05). The lowest toxicity was detected for END (p < 0.05). BC had the highest inhibitory effect on osteoclasts (p < 0.05). Overall, the highest solubility and pH values were found in DW. However, the calcium silicate-based sealer showed higher solubility than the ISO standards. Calcium release was the highest for BC. END showed the highest cell viability, and BC, the highest osteoclast inhibition.

Different formulations of peracetic acid: effects on smear layer removal, dentine erosion, cytotoxicity and antibiofilm activity

Abstract Objective: To assess the effects of different peracetic acid (PAA) formulations on smear layer (SL) removal, dentine erosion, cytotoxicity, and antibiofilm activity. Methodology: SL removal and dentine erosion were assessed using 90 premolars, distributed into six groups, according to final irrigation: PAA formulations (1% Sigma, 1% Bacterend OX, 1% Arposept, and 0.09-0.15% Anioxyde), 17% ethylenediaminetetraacetic acid (EDTA), and water (control). Cytotoxicity was assessed by methyl-thiazol-tetrazolium (MTT) and neutral red assays. Antibacterial and antibiofilm effectiveness was evaluated against Enterococcus faecalis. For cytotoxicity and antibiofilm activity assessment, the 2.5% NaOCl was also included. Results: EDTA, Sigma, and Bacterend OX removed more SL than Arposept, Anioxyde, and water (p<0.05). EDTA caused more severe dentine erosion than Sigma and Bacterend OX (p<0.05). Sigma and Bacterend OX had higher cytotoxicity than the other solutions (p<0.05). NaOCl, Bacterend OX, Sigma, and Anioxyde significantly reduced E. faecalis colony-forming units (CFU) (p<0.05). The 2.5% NaOCl solution promoted greater biofilm biomass reduction (p<0.05) than the other solutions. All PAA formulations promoted greater biomass reduction than 17% EDTA (p<0.05). Conclusions: Although Sigma and Bacterend OX had higher cytotoxicity, they had a SL removal capability similar to that of EDTA, were as effective as NaOCl against E. faecalis biofilm, and promoted less dentine erosion than EDTA. Arposept and Anioxyde failed to remove the SL, had lower cytotoxicity, and showed less bacterial activity than NaOCl.

Efeito do momento de imersão na alteração volumétrica do agregado trióxido mineral HP / Effect of the immersion moment at the volumetric alteration of the mineral trioxide aggregate HP

Introdução: A solubilidade é uma propriedade relaciona- da à dissociação dos constituintes do material, pela ação do contato com o líquido circundante. Introdução: O objetivo do presente estudo foi avaliar o efeito da hidratação durante a varredura com microtomografia (micro-TC) sobre a alteração volumétrica do MTA HP. Métodos: foram utilizados 20 dentes incisivos superiores de acrílico com cavidade retrógrada. O cimento MTA HP foi inserido na cavidade com um condensador Paiva. As amostras foram inspecionadas visualmente com uma lupa de 5x, para garantir que não permanecessem espaços vazios ou lacunas. Os espécimes foram divididos em dois grupos (n=10). Os dentes foram escaneados logo após o manuseio do MTA. Para o grupo com imersão em água, Eppendorf hidratado foi mantido com 1mL de água durante a varredura; no outro grupo, os dentes foram escaneados sem água. Nos dois grupos, os dentes foram imersos em água durante sete dias. Em seguida, os dentes foram escaneados novamente em micro-TC usando os mesmos parâmetros e condições de cada grupo. Foi realizada a reconstrução das imagens pelo software Nrecon e o volume de solubilidade, determinado pelo software CTan, analisando-se a variação volumétrica. Resultados: O grupo de corpos de prova escaneados imersos na água apresentou maior variação volumétrica, com diferenças estatisticamente significativas em relação ao grupo escaneado sem imersão. O escaneamento do corpo de prova imerso em água favorece uma maior perda volumétrica do material. Conclusão: Os estudos para avaliar a variação volumétrica de cimentos de silicato de cálcio devem ser feitos com imersão em água.

Introduction: Solubility is a property related to the dissocia- tion of the constituents of the material by the action of contact with the surrounding liquid, for this reason, the aim of this study was to evaluate the effect of the hydration during the scanning in the microtomography on the volumetric alteration of the MTA HP. Methods: Twenty acrylic teeth upper incisor with retrograde cavity were utilized. The MTA HP cement was inserted into the cavity using a Paiva condensor. The specimens were visually inspected with a 5x magnifying glass to ensure they did not remain void or gaps. The specimens were divided into 2 groups (n=10). The teeth were scanned shortly after handling the MTA. For the group with water immersion, hydrated Eppendorf was kept with 1mL the water during the scanning and the other group, the teeth were scanning without water. In the two groups the teeth were immersed into water during 7 days. Next the teeth were newly scanned in the Micro-CT using the same parameters and conditions of each group. Reconstruction of images by the Nrecon software and the solubility volume determined by the CTan, analyzing the volumetric change. Results: The group of specimens scanned immersed into the water presented higher volumetric change with statistically significant differences in relation the group scanned without immersion. The scanning of the specimen immersed in water favors the greater volumetric loss of the material. Conclusion: Studies to evaluate volumetric change of calcium silicate cements should be made immersed in wate

Physicochemical properties, cytocompatibility and antibiofilm activity of a new calcium silicate sealer

Abstract The aim of this study was to evaluate the physicochemical properties, cytocompatibility and antibiofilm activity of a new calcium silicate-based endodontic sealer, Sealer Plus BC (MK Life, Brazil), in comparison with TotalFill BC Sealer (FKG Dentaire SA, Switzerland) and AH Plus (Dentsply, Germany). Setting time and flow were evaluated based on ISO 6876 standard. The pH was evaluated after different periods, and radiopacity by radiographic analysis (mmAl). Solubility (% mass loss) and volumetric change (by micro-CT) were assessed after 30 days of immersion in distilled water. Cytocompatibility was assessed by methyltetrazolium (MTT) and neutral red (NR) assays, after exposure of Saos-2 cells to the sealer extract for 24 h. An additional analysis was performed by using MTT assay after 1, 3 and 7 days of exposure of Saos-2 to the sealers 1:8 dilution extracts. Antibiofilm activity against Enterococcus faecalis and/or Candida albicans was evaluated by crystal violet assay and modified direct contact test. The physicochemical properties were analyzed using ANOVA/Tukey tests; MTT and NR data were analyzed by ANOVA and Bonferroni tests; the antimicrobial tests were analyzed by Kruskal-Wallis and Dunn tests (α=0.05). Sealer Plus BC had proper setting time, radiopacity, flow and alkalization capacity. Sealer Plus BC was significantly more soluble than AH Plus (p<0.05) and presented volumetric change similar to AH Plus and TotalFill BC (p>0.05). Sealer Plus BC presented antibiofilm activity and no cytotoxic effect. In conclusion, although Sealer Plus BC had higher solubility, this sealer showed proper physicochemical properties, cytocompatibility, and antibiofilm activity.

Resumo O objetivo deste estudo foi avaliar as propriedades físico-químicas, a citocompatibilidade e a atividade antibiofilme de um novo cimento endodôntico à base de silicato de cálcio, Sealer Plus BC (MK Life, Brasil), em comparação com TotalFill BC Sealer (FKG Dentaire SA, Suíça) e AH Plus (Dentsply, Alemanha). O tempo de presa e o escoamento foram avaliados com base nas normas ISO 6876. O pH foi avaliado após diferentes períodos, e a radiopacidade por análise radiográfica (mmAl). A solubilidade (% de perda de massa) e alteração volumétrica (por micro-CT) foram avaliadas após 30 dias de imersão em água destilada. Citocompatibilidade foi avaliada pelos ensaios metiltetrazólio (MTT) e vermelho neutro (NR), após exposição das células Saos-2 ao extrato de cimento por 24 horas. Análise adicional foi realizada através do ensaio MTT após 1, 3 e 7 dias de exposição das células Saos-2 aos extratos dos cimentos na diluição de 1:8. Atividade antibiofilme contra Enterococcus faecalis e/ou Candida albicans foi avaliada pelos ensaios cristal violeta e contato direto modificado. As propriedades físico-químicas foram analisadas utilizando os testes ANOVA e Tukey; MTT e NR foram analisados pelos testes ANOVA e Bonferroni; os ensaios antimicrobianos foram analisados pelos testes Kruskal-Wallis e Dunn (α=0.05). Sealer Plus BC apresentou tempo de presa, radiopacidade e escoamento adequados, além de capacidade de alcalinização. Sealer Plus BC foi significantemente mais solúvel que AH Plus (p<0.05) e apresentou alteração volumétrica similar à de AH Plus e TotalFill BC (p>0.05). Sealer Plus BC apresentou atividade antibiofilme, sem efeito citotóxico. Como conclusão, embora Sealer Plus BC apresente maior solubilidade, este cimento apresentou propriedades físico-químicas adequadas, citocompatibilidade e atividade antibiofilme.

Influência da agulha e fluxo de irrigação na limpeza do canal radicular e extrusão apical de irrigante: análise em micro-CT / Influence of needle and irrigation flow rate on root canal cleaning and apical extrusion of irrigant: Micro-CT analysis

Introdução: O tipo de agulha e fluxo de irrigação é importante para a limpeza adequada no terço apical do canal radicular. Objetivo: Avaliar a influência do tipo de agulha e fluxo de irrigação na limpeza do canal radicular e canais laterais simulados e na extrusão apical do irrigante. Métodos: Trinta e dois dentes de resina foram utiliza- dos. Após a instrumentação do canal radicular, foram feitos quatro canais laterais a 2 e 7 mm do ápice. Os canais radiculares foram preenchidos com solução de contraste. Os canais foram irrigados com dois tipos de agulha, 29G e 31G, com diferentes designs (abertura lateral e apical) e dois fluxos (2 ou 5 mL/min), a 1 mm aquém do comprimento de trabalho. O volume da solução de contraste nos canais principal e laterais após irrigação e a extrusão apical do irrigante (mm3 ) foi avaliado por micro-CT, em comparação com a análise inicial. Os dados em porcentagem foram analisados pelos testes ANOVA e Tukey (α=0,05). Resultados: não houve diferença entre os protocolos de irrigação para limpeza da solução de contraste. Maior volume de extrusão apical com agulha 29G com abertura apical e 5 mL/min foi observado, em comparação ao mesmo tipo de agulha e 2 mL/min (p<0,05). Conclusão: Todos os protocolos de irrigação foram associados à limpeza dos canais radiculares. Maior extrusão apical foi observada com agulha 29G ­ abertura apical com maior fluxo de irrigação (5 mL/min). Implicações clínicas: Irrigação endodôntica com agulha com abertura apical e maior fluxo da solução pode favorecer a extrusão dos irrigantes para os tecidos periapicais (AU).

Introduction: needle and irrigation flow rate are important for proper cleaning of the root canal. Aim: to evaluate the influence of type of needle and irrigation flow rate on cleaning of root canal and simulated lateral canals and the apical extrusion of irrigant. Methods: Thirty-two resin teeth were used. After root canal instrumentation, four lateral canals were made at 2 and 7 mm from the apex. Root canals were filled with contrast solution. The root canals were irrigated with two types of needle, 29G and 31G, with different designs (side and apical opening) and two flow rates (2 or 5 mL/min), at 1 mm short of the working length. The volume of the contrast solution in the main and lateral canals after irrigation and apical extrusion of the irrigant (mm3) were evaluated by Micro-CT, in comparison with the initial analysis. Data in percentage were analyzed by ANOVA and Tukeys tests (α = 0.05). Results: no difference among the irrigation protocols for contrast solution cleaning was observed. Higher volume of apical extrusion using needle 29G-apical opening and 5 mL/min in comparison with the same type of needle and 2 mL/min was observed (p < 0.05). Conclusion: all irrigation protocols were associated with root canals cleaning. Greater apical extrusion was observed for needle 29G-apical opening with higher irrigation flow rate (5 mL/min). Clinical implications: endodontic irrigation using a needle with apical opening and higher flow rate of solution may favor extrusion of irrigant to the periapical tissues (AU).

Physicochemical properties and effect of bioceramic root canal filling for primary teeth on osteoblast biology

Abstract Bio-C Pulpecto (Bio-CP) was recently developed as the first bioceramic root filling material for primary teeth. Objective To evaluate the physicochemical properties of radiopacity, setting time, pH, cytocompatibility and potential of Bio-CP to induce mineralisation, compared with (1) Calen thickened with zinc oxide (Calen-ZO), and (2) zinc oxide and eugenol (ZOE). Methodology Physicochemical properties were evaluated according to ISO 6876. Saos-2 (human osteoblast-like cell line) exposed to extracts of the materials were subjected to assays of methyl thiazolyl tetrazolium, neutral red, alkaline phosphatase (ALP) activity and mineralised nodule production. The results were analysed using one-way or two-way ANOVA and Tukey's or Bonferroni's post-tests (α=0.05). Results All the materials showed radiopacity higher than 3 mm Al. Bio-CP had lower pH than Calen-ZO, but higher pH than ZOE. Calen-ZO and Bio-CP did not set. The setting time for ZOE was 110 min. The cytocompatibility order was Calen-ZO > Bio-CP > ZOE (1:2, 1:4 dilutions) and Calen-ZO > Bio-CP = ZOE (1:12, 1:24 dilutions) and Calen-ZO = Bio-CP > ZOE (1:32 dilution). Bio-CP induced greater ALP activity at 7 days, and greater mineralised nodule production, compared to Calen-ZO (p<0.05). Conclusions Bio-CP showed adequate physicochemical properties, cytocompatibility and potential to induce mineralisation.

Effect of irrigation protocols on root canal wall after post preparation: a micro-CT and microhardness study

Abstract: The aim of this study was to investigate the effects of different post space irrigation protocols for removing residual filling material from dentin walls, by using microcomputed tomography (micro-CT), and the influence of these protocols on dentin microhardness. Bovine incisors (n = 35) were filled with the single-cone technique and MTA Fillapex (Angelus, Londrina, PR, Brazil). Post space preparation (PSP) was performed 7 days after filling, using the Odous Touch electrical system (Odous De Deus Ind. e Com., Belo Horizonte, MG, Brazil), followed by post space irrigation using manual irrigation, passive ultrasonic irrigation, or Easy Clean, together with 2.5% sodium hypochlorite (NaOCl), or with 2.5% NaOCl and 17% EDTA (NaOCl/EDTA). Micro-CT scans were performed at three time points. The residual filling material was evaluated at three levels: cervical, middle and apical. The Knoop test was measured with four indentations around the canal lumen at three dentin depths: X (100 μm), Y (200 μm) and Z (400 μm). Statistical analysis was performed using ANOVA (p < 0.05). The effects of the activation method (p < 0.001), and the root level (p = 0.013), as well as the interaction between the irrigant and the activation method (p = 0.041), led to different percentages of residual filling material. Lower amounts of residual filling material were observed at the cervical versus the middle and apical levels (p < 0.05). No significant differences were observed in dentin microhardness (p > 0.05). The best removal of the residual filling material was performed using the Easy Clean tip and NaOCl/EDTA, regardless of the activation methods.

Influence of voxel size on dentinal microcrack detection by micro-CT after root canal preparation

Abstract The aim of this study was to assess the influence of micro-computed tomography (micro-CT) voxel size on dentinal microcrack detection after root canal preparation using rotary heat-treated nickel-titanium files. Curved mesial root canals (n = 24) of mandibular molars were prepared using ProDesign Logic 30/.05 (PDL) or HyFlex EDM 25/.08 (HEDM). The specimens were scanned by micro-CT at 5 μm voxel size before and after root canal preparation. The percentage of microcracks was evaluated in images at 5, 10 and 20 μm voxel size, by two examiners at two moments. The Kappa and McNemar tests (α = 0.05) were used. The percentage of dentinal microcracks was similar before and after PDL and HEDM preparations, at 10 and 20 μm (p > 0.05). HEDM showed a higher percentage of dentinal microcracks in the middle third at 5 μm after preparation (p < 0.05). The detection of dentinal microcracks before and after instrumentation using PDL was more accurate at 5 μm than at 20 μm, in all thirds (p < 0.05). Within the limitations of this ex vivo study, as expected, the results showed that different resolutions influence the micro-CT analysis of microcracks. The highest accuracy in detecting microcracks was observed for analyses performed at 5 μm voxel size. HyFlex EDM caused even more microcracks to develop in the middle third, detectable only by visualization of images made at 5 μm voxel size.

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.