Abstract Dental materials should be stable over time. This study investigated volumetric change of the root canal sealers AH Plus, Fill Canal, and Sealapex; and the root-end filling materials Biodentine, IRM, and MTA after different periods of immersion in distilled water. Resin models were manufactured with cavities 3 mm deep. The cavities were filled with the materials and scanned by microcomputed tomography after setting, and after 7 and 30 days immersed in distilled water. Percentages of volumetric changes after 7 and 30 days of immersion were compared by t-test. ANOVA/Tukey tests were used to compare endodontic materials (5% significance level). All root canal sealers had an increase in their volumetric change after 30 days. Among root-end filling materials, only IRM showed difference between the periods. Biodentine showed more volumetric changes than MTA, but both materials kept their volume from 7 to 30 days. In conclusion, the immersion period of endodontic materials may affect their stability.

Resumo O objetivo deste estudo foi avaliar propriedades físicas de cimentos endodônticos (AH Plus, MTA Fillapex e Endofill), por meio de testes convencionais e micro-CT. A estabilidade dimensional foi avaliada após imersão dos materiais em água destilada por 30 dias. A solubilidade e a alteração volumétrica dos materiais foram avaliadas após 7 e 30 dias de imersão em água destilada. A solubilidade foi avaliada por meio de perda de massa e a alteração volumétrica foi avaliada por micro-CT. A porosidade foi avaliada por microscopia após 7 dias de imersão em água destilada e por micro-CT após a presa e imersão em água destilada por 7 e 30 dias. A análise estatística foi realizada por meio dos testes ANOVA e Tukey, com nível de significância de 5%. MTA Fillapex apresentou a maior solubilidade (p<0,05), com valores acima das recomendações ISO/ADA. As alterações volumétricas e dimensionais foram maiores para MTA Fillapex, seguido por Endofill e AH Plus (p<0,05). MTA Fillapex e AH Plus não cumpriram os padrões ISO/ADA em relação à estabilidade dimensional. Uma maior porosidade total foi observada para MTA Fillapex (p <0,05). Endofill apresentou maior porosidade total que o AH Plus pela avaliação em microscopia (p<0,05), e ambos os cimentos foram semelhantes na avaliação por micro-CT (p>0,05). Em conclusão, MTA Fillapex apresentou maior solubilidade, alteração dimensional e volumétrica, além de maior porosidade em relação aos demais cimentos avaliados. As propriedades físicas avaliadas estão relacionadas, e os diferentes testes forneceram dados complementares. Micro-CT é um método valioso para avaliação das propriedades físicas dos materiais endodônticos.

Abstract The aim of this study was to evaluate physical properties of endodontic sealers (AH Plus, MTA Fillapex and Endofill), by conventional and micro-CT tests. Dimensional stability was evaluated after immersion of materials in distilled water for 30 days. Solubility and volumetric change were evaluated after 7 and 30 days of immersion in distilled water. Solubility was evaluated by means of mass loss and volumetric change was assessed by micro-CT. Porosity was evaluated under a microscope after 7 days of immersion in distilled water, and by using micro-CT after setting and immersion in distilled water for 7 and 30 days. Statistical analysis was performed by ANOVA and Tukey’s test with 5% significance level. MTA Fillapex presented the highest solubility (p<0.05), showing values above the ISO/ADA recommendations. MTA Fillapex presented higher volumetric and dimensional changes, followed by Endofill and AH Plus (p<0.05). Dimensional stability of the MTA Fillapex and AH Plus did not follow ISO/ADA standards. The highest total porosity was observed for MTA Fillapex (p<0.05). Endofill had higher total porosity than AH Plus according to microscope evaluation (p<0,05), and both sealers were similar in micro-CT assessment (p>0,05). In conclusion, MTA Fillapex presented higher solubility, dimensional and volumetric change besides porosity compared to the other evaluated sealers. The assessed physical properties of sealers are related, and the different tests provided complementary data. Micro-CT is a valuable method for assessment of physical properties of endodontic materials.

Resumo Introdução Capacidade de preenchimento da cavidade retrógrada e porosidade são propriedades importantes de materiais retrobturadores e podem ser avaliadas por meio de microtomografia computadorizada (micro-CT). Objetivo Avaliar a capacidade de preenchimento e porosidade de materiais retrobturadores por meio de micro-CT. Material e método Cavidades com 1 mm de diâmetro e 3 mm de altura foram preparadas em dentina bovina utilizando pontas ultrassônicas (CVD No. 6.1107-6) e foram preenchidas com Mineral Trióxido Agregado (MTA), Sealer 26 (S26) e cimento de óxido de zinco e eugenol (OZE). As cavidades foram escaneadas em micro-CT antes e após o preenchimento. A capacidade de preenchimento foi calculada com base na porcentagem em volume, das cavidades preenchidas. O número e porcentagem dos poros fechados foram avaliados em toda extensão da cavidade preenchida (total) e por terços (cervical, médio e apical) por meio de análises bi e tridimensionais. Os dados de preenchimento foram submetidos aos testes estatísticos ANOVA e Tukey e a porosidade aos testes de Kruskall-Wallis e Dunn, com nível de significância de 5%. Resultado S26 e OZE apresentaram maior capacidade de preenchimento que o MTA (p<0,05). S26 mostrou maior porosidade total (em número e porcentagem) (p<0,05). Em todos os terços, após as análises 2D e 3D, a porosidade foi maior para S26 em comparação ao MTA e OZE (p<0,05). Conclusão Embora Sealer 26 tenha apresentado maior porosidade, o material foi associado a uma adequada capacidade de preenchimento. A análise em micro-CT mostrou ausência de correlação entre capacidade de preenchimento e porosidade.

Abstract Introduction Filling ability of retrograde cavity and porosity are important properties for root-end filling materials and may be evaluated by using microcomputed tomography (micro-CT). Objective To evaluate filling ability and porosity of root-end filling materials using microcomputed tomography (micro-CT). Material and method Cavities with 1 mm internal diameter and 3 mm depth were prepared in bovine dentin sections by using ultrasonic tips (CVD No. 6.1107-6), and filled by Mineral Trioxide Aggregate (MTA); Sealer 26 (S26) and zinc oxide and eugenol cement (ZOE). Before and after filling, cavities were scanned by using micro-CT (SkyScan 1176). Filling and porosity were analyzed by using CTAn software. Filling ability was calculated based on volumetric percentage of the filled cavity. The number and percentage of closed pores were measured throughout entire extension of the filled cavity (total) and in each third (cervical, middle and apical), by using bi and tridimensional analyses. The filling data were submitted to ANOVA and Tukey statistical tests, and porosity data to Kruskall-Wallis and Dunn tests, at a 5% significance level. Result S26 and ZOE presented higher filling ability than MTA (p<0.05). S26 showed the highest total porosity (number and percentage) (p<0.05). In all thirds after 2D and 3D analyses, porosity was higher for S26 in comparison to MTA and ZOE (p<0.05). Conclusion Although Sealer 26 presented more porosity, the material was associated with a great filling ability. Micro-CT analysis showed no correlation between filling ability and porosity.

Abstract Objective To evaluate solubility, dimensional stability, filling ability and volumetric change of root-end filling materials using conventional tests and new Micro-CT-based methods. Material and Methods Solubility (loss of mass) after 7 and 30 days, and dimensional stability (in mm) were evaluated in accordance with Carvalho-Junior, et al. 7 (2007). The filling ability and volumetric change (in mm3) were evaluated by Micro-CT (Bruker-MicroCT, Kontich, Belgium) using resin models with cavities 3 mm deep and 1 mm in diameter. The cavities were filled with materials to evaluate filling ability, and then scanned by Micro-CT. After 7 and 30 days immersed in distilled water, the filled cavities were scanned again to evaluate the volumetric change. MTA Angelus (MTA), Biodentine (BIO) and zinc oxide-eugenol cement (ZOE) were evaluated. Data were submitted to analysis of variance (ANOVA) and Tukey's test with 5% significance level. Results The results suggested correlated or complementary data between the proposed tests. At 7 days, BIO showed higher solubility and at 30 days, showed higher volumetric change in comparison with MTA (p<0.05). With regard to volumetric change, the tested materials were similar (p>0.05) at 7 days. At 30 days, they presented similar solubility. BIO and MTA showed higher dimensional stability than ZOE (p<0.05). ZOE and BIO showed higher filling ability (p<0.05). Conclusions ZOE presented a higher dimensional change, and BIO had greater solubility after 7 days. BIO presented filling ability and dimensional stability, but greater volumetric change than MTA after 30 days. Micro-CT can provide important data on the physicochemical properties of materials complementing conventional tests.

ABSTRACT Objective To evaluate solubility and sealing ability of Mineral Trioxide Aggregate (MTA) and root-end filling materials. Material and Methods The materials evaluated were: MTA, Calcium Silicate Cement with zirconium oxide (CSC/ZrO2), and zinc oxide/eugenol (ZOE). Solubility test was performed according to ANSI/ADA. The difference between initial and final mass of the materials was analyzed after immersion in distilled water for 7 and 30 days. Retrograde cavities in human teeth with single straight root canal were performed by using ultrasonic tip CVD 9.5107-8. The cavities were filled with the evaluated materials to evaluate sealing ability using the bacterial leakage test with Enterococcus faecalis. Bacterial leakage was evaluated every 24 hours for six weeks observing the turbidity of Brain Heart infusion (BHI) medium in contact with root apex. Data were submitted to ANOVA followed by Tukey tests (solubility), and Kruskal-Wallis and Dunn tests (sealing ability) at a 5% significance level. Results For the 7-day period, ZOE presented highest solubility when compared with the other groups (p<0.05). For the 30-day period, no difference was observed among the materials. Lower bacterial leakage was observed for MTA and CSC/ZrO2, and both presented better results than ZOE (p<0.05). Conclusion MTA and CSC/ZrO2 presented better bacterial sealing capacity, which may be related to lower initial solubility observed for these materials in relation to ZOE.