Estimation of the amount of bismuth trioxide as radiopacifying agent by a radiopacity test in two mineral trioxide aggregate cements

Flores-Ledesma, Abigailt; Gutiérrez-Estrada, Kenya; Bucio-Galindo, Lauro; Flores-Ledesma, Abigailt; Gutiérrez-Estrada, Kenya; Bucio-Galindo, Lauro

doi:10.22201/fo.1870199xp.2019.23.3.75622

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Revista odontológica mexicana

versión impresa ISSN 1870-199X

Rev. Odont. Mex vol.23 no.3 Ciudad de México jul./sep. 2019 Epub 31-Mar-2025

https://doi.org/10.22201/fo.1870199xp.2019.23.3.75622

Original research

Estimation of the amount of bismuth trioxide as radiopacifying agent by a radiopacity test in two mineral trioxide aggregate cements

Abigailt Flores-Ledesma¹^*

Kenya Gutiérrez-Estrada²

Lauro Bucio-Galindo³

^¹ Laboratorio de Biomateriales Dentales. División de Estudios de Postgrado e Investigación, Facultad de Odontología, Universidad Nacional Autónoma de México.

^² Práctica Privada Especialista en Endodoncia egresada de la División de Estudios de Postgrado e Investigación, Facultad de Odontología, Universidad Nacional Autónoma de México.

^³ Instituto de Física, Universidad Nacional Autónoma de México.

Abstract

The mineral trioxide aggregate (MTA) cement contains approximately 20%wt of bismuth trioxide (Bi₂O₃), a radiopacifying material. However, the radiopacity reported in several commercial brands of these cements is variable because they have different amounts of bismuth, which affects its mechanical properties.

Objective:

To estimate by a radiopacity test the concentration of Bi₂O₃ in two brands of MTA cements available in Mexico.

Materials and methods:

Five mixtures of white Portland cement (WPC) with Bi₂O₃ concentrations of 0%, 10%, 15%, 20%, and 25%wt (WPC, Bi10%, Bi15%, Bi20%, Bi25%) and four lots of two commercial cements (two lots each), MTA Angelus and MTA Viardent, were analyzed by a radiopacity test according to the international Standard ISO 6876. These values were determined on the basis of radiographic density (shades of grey) and converted to millimeters of aluminum (mm Al). A linear adjustment was made with the mixtures of WPC and bismuth; the straight line equation was used to calculate the concentration of Bi₂O₃ in commercial cements.

Results:

Radiopacity increased with higher amounts of Bi₂O₃; the WPC obtained a radiopacity of 1.8 mm Al, while for Bi25% radiopacity was 6 mm Al. The 20%wt concentration was used as control; a statistically significant difference was observed in Bi15%, Bi10%, WPC, and MTA Angelus (p<0.05). In the MTA Viardent the amount of bismuth is 24-25%wt, while in the MTA Angelus is between 20-32%wt.

Conclusions:

Commercial cements have a higher bismuth concentration than recommended, which increases their radiopacity and may compromise their mechanical properties.

Keywords: Trioxide aggregate cement; radiopacity; bismuth trioxide; calcium silicate-based cements

Resumen

Se dice que el cemento mineral trióxido agregado (MTA) contiene 20%wt de trióxido de bismuto (Bi₂O₃) que le provee radiopacidad; sin embargo, la radiopacidad reportada en varias marcas de estos cementos ha sido variable, lo que sugiere que presentan diversa cantidad de bismuto, pudiendo afectar sus propiedades mecánicas.

Objetivo:

Estimar la concentración de trióxido de bismuto en dos marcas comerciales disponibles en México a partir de una prueba de radiopacidad.

Material y métodos:

Cinco mezclas de cemento portland blanco (CPB) con concentraciones de Bi₂O₃ al 0, 10, 15, 20 y 25%wt (CPB, Bi10%, Bi15%, Bi20%, Bi25%), se analizaron dos lotes de dos cementos comerciales: MTA Angelus y MTA Viardent mediante una prueba de radiopacidad de acuerdo a la ISO 6876. Estos valores fueron determinados con base en la densidad radiográfica (tonos de grises) y convertidos a milímetros de aluminio (mm Al); se realizó un ajuste lineal con las mezclas del CPB y bismuto; se utilizó la ecuación de la recta para calcular la concentración de Bi₂O₃ en los cementos comerciales.

Resultados:

Se observó aumento de radiopacidad a mayor cantidad de trióxido de bismuto, el CPB obtuvo una radiopacidad de 1.8 mm Al, mientas que en el Bi25% fue de 6 mm Al. La concentración de 20%wt se usó como control, se observaron diferencias estadísticamente significativas en Bi15%, Bi10%, cemento Portland blanco y MTA Angelus (p < 0.05). En el MTA Viardent la cantidad de bismuto es de 24-25%wt, mientras que el MTA Angelus presenta entre 20-32%wt.

Conclusiones:

Los cementos comerciales muestran una concentración de bismuto mayor que la sugerida, lo que aumenta la radiopacidad de éstos, pudiendo afectar las propiedades mecánicas.

Palabras clave: Mineral trióxido agregado radiopacidad; trióxido de bismuto; cementos de silicato de calcio

Introduction

The mineral trioxide aggregate (MTA) was developed by Torabinejad et al.¹ at Loma Linda University in 1995. This compound has various clinical applications within the dental field, specifically in endodontics and pediatric dentistry. MTA has been suggested for use in apexification,²,³ as spray coating,⁴,⁵ repairer of furcal perforation during drilling,⁶,⁷ and material for retro-obturation.⁸

Silicate-based cements such as MTA have good biological properties; they stimulate the formation of mineralized tissue in pulp cells, the proliferation of bone tissue and thus the maturation activity of osteoblastic cells⁹-¹³ as well as the formation of apatites and stimulation of stromal cells.¹⁴-¹⁶ These qualities have been tested both in vitro¹⁷,¹⁸ and in vivo.¹⁹

The composition of white Portland cement is mainly based on tricyclic silicate, dicalcium silicate, and tricyclic aluminate.²⁰,²¹ MTA cements are composed of 80% Portland cement and 20% bismuth trioxide (Bi₂O₃), which provides radiopacity.²²-²⁴ To date, the biggest disadvantage of MTA cements is their long setting time of about 72 hours.²⁵ To overcome this drawback some accelerators have been used, such as calcium chloride, citric acid, calcium gluconate, chlorhexidine gluconate, and sodium hydroxide.²⁶-²⁸ Also, some materials have been added, such as bioactive glass and wollastonite.²⁹ These aids, however, have showed that MTA cements are sensitive to changes in their composition so their mechanical properties become weakened.

Some studies have tested various concentrations of radiopacifying materials, such as bismuth trioxide³⁰ or zirconium oxide.³¹ In both cases the physical properties of the cements were affected; the resistance to compression decreased, while porosity, setting time and solubility increased.³²-³⁴ These variations may lead to future treatment failures.

On the other hand, several studies have shown that MTA cement produces gingival and dental coloration changes toward brown or black tones.³⁵,³⁶ Initially changes were believed to be because by gray MTA, which has iron as one of its components. However, this color change has also been observed using white MTA.³⁷,³⁸ Subsequent studies have shown that the change in color is caused by bismuth,³⁹,⁴⁰ which is sensitive to contact with sodium hypochlorite³⁵,⁴¹ and light exposure.⁴²

The radiopacity of commercial MTA cements is highly variable with values ranging from 4 millimeters of aluminum (mm Al) to 7 mm Al.⁴³,⁴⁴ Radiopacity is related to the amount and type of radiopacifier; hence the objective of this study was to estimate the amount of bismuth trioxide in two different brands of MTA cements available in Mexico, by means of a radiopacity test.

Materials and methods

For this study we used five mixtures of white Portland cement (Cruz Azul, Mexico, Lot 033442), previously characterized20 with bismuth trioxide (Aldrich Chemical Company Inc., Lot 1304-76-3) at concentrations of 0, 10, 15, 20 and 25%wt, and two commercial cements, i.e. two lots of MTA Angelus (Angelus Dental Products Industry, Londrine, Brazil, lots 21934 and 20939) and two lots of MTA Viardent (Mexico, lots 160715 and A030317).

The methodology of this study followed the specified requirements for radiopacity of the international Standard ISO 6876.⁴⁵ Each of the cements was prepared at a ratio of 1 g powder/0.33 mL water.⁴⁶,⁴⁷ The mixture was placed inside a pill mold (n = 10) with internal diameter of 10 ± 0.1 mm and height of 1 ± 0.01 mm. Pressure was applied with a glass plate and the mold was placed in a C press to obtain pills with flat surfaces, free of pores and internal bubbles. The mold together with the press was placed inside an ambient chamber (Polyscience, USA, Mod. 106B 00351) at 37 oC and relative humidity of 95% for 24 hours. After this time the pills were placed on an occlusal radiograph (E-Speed Film, Kodak, Rochester, NY, Lot 3109744), along with a radiopacity indicator (aluminum stepped rack, 0.5 mm each step, purity of 95.5%).

The samples, the radiograph, and the rack were placed on a lead base for x-ray taking; irradiation was performed with an X-ray device (Progeny Dental, Model JB-70, USA, 65-5 kV) at a film distance of 30 cm from the focal point (distance was standardized with an acetate cylinder) and exposure lasted 0.15 seconds. The radiograph was developed following the times displayed in Table 1, with Kodak® developing liquids (Kodak, Rochester, NY, Lot 1011 C6 02819).

Table 1: Developing times of radiographs.

Revelador	Agua	Fijador	Agua
15 seg.	15 seg.	3 min.	15 seg.

The radiograph was placed in the center of the negatoscope, which was covered with a cardboard box to limit outside light. The box had a hole through which the lens of the digital camera was adjusted (Lumix, Panasonic Mod FH20, China) to obtain digital X-rays. X-ray density was analyzed on the basis of a grayscale with ImageJ 1.44 (National Institutes of Health, USA) imaging software.

The radiopacity values were determined according to radiographic density (shades of gray) and converted to millimeters of aluminium (mm Al). The conversion was made following the formula reported by Vivan:⁴⁸

A×2B+mm Al inmediatos a la densidad radiográfica del material (DRM)

Where A: RDM - radiographic density of the aluminum rack increase immediate below RDM and B: radiographic density of the aluminum rack increase immediate above RDM - radiographic density of the aluminum rack increase immediate below DRM.

The results were analyzed using SPSS version 23. Since Bi20% concentration has been established as standard in the MTA patent,⁴⁹ the Bi20% group was taken as control. Kolmogorov-Smirnov test was performed to test the normality of the data, and parametric tests were carried out. ANOVA and post hoc Dunnett tests were performed with 95% confidence interval.

Results

The radiopacity of the experimental cements, MTA Angelus and MTA Viardent, is shown in Figure 1. The increase in radiopacity is clearly observed according to the amount of added bismuth trioxide. White Portland cement had a radiopacity of 1.8 mm Al; at Bi10% it increased to 2.8, with increasing values of 4.3, 5.7, and 6.0 mm Al at Bi15%, Bi20%, and Bi25%, respectively. Statistically significant differences were found in the cements with Bi15% and Bi10%, white Portland cement, and MTA Angelus (lot 21934) when compared with the Bi20% group (control).

Figure 1: Results of the radiopacity test, ANOVA p < 0.05, post hoc Dunnett test p < 0.05; the Bi20% group was used as control. The numbers at the bottom and the error bars represent the means for each group and the standard deviation, respectively (n = 10).

The radiopacity mean of the cements with 0, 10, 15, 20 and 25% wt bismuth trioxide concentrations were plotted, with a linear adjustment. The straight line equation and R value were obtained (Figure 2). This equation was used to clear the value of X, using the slope and intersection values to calculate the bismuth concentration in each of the commercial cements (Table 2).

Figure 2: Graph of the bismuth trioxide concentration. The linear adjustment was made to obtain the straight line equation (n=10). The mean and the standard deviation were plotted.

Table 2: Estimated concentration of bismuth trioxide in the commercial cements studied.

	MTA Angelus Lote-21934	MTA Angelus Lote-20939	MTA Viardent Lote 160715	MTA Viardent Lote 030317
% de Bi₂O₃	32.3	20.6	24.5	25.6

In the case of MTA Viardent, the concentration of bismuth trioxide varied between 24-25%, whereas in the MTA Angelus the concentration varied between 20-32%.

Discussion

The international Standard ISO 6876 «Specification for dental root canal sealing materials»⁴⁵ states that 1 mm of such materials must have at least 3 mm of aluminum in order to show an adequate radiopacity. The addition of 20wt% bismuth trioxide helps achieve this goal.⁴⁹ The basic composition of MTA is 80% Portland cement,²⁰,²³ which has a radiopacity of 1.8 mm Al, a value similar to that obtained by Hungaro- Duarte⁵⁰ of 1.01 mm Al, although the latter is not ideal for identification.

According to Grossman,⁵¹ the ideal obturating material must present among its properties sufficient radiopacity. This quality allows distinguishing the material from the surrounding structures to ensure the correct performance of obturations and sealing in root canals, perforations, and retropreparations. In turn, this favors the elimination of persistent disease in endodontic treatment.⁵²

When using a calcium silicate-based cement it is important to check radiographically that it is located within the cavity or in the desired area; that it is well compacted, it can be differentiated from dentin and bone, in cases of re-calibration in periapical surgery, and it obturates together with guttapercha in root canal treatments, i.e. that these materials are distinguishable ensuring the sealing of both. A material with poor radiopacity may cause confusion with the anatomical areas of dentin, bone, and periodontal ligament. On the contrary, a more radiopaque material with strong contrast can lead to the false impression of a dense and homogeneous filling and it can mask gaps in the obturation where the material has not penetrated properly.⁵²

Hence the need to perform radiopacity tests on calcium silicate-based cements in order to confirm that they meet the requirements set by ISO 6876.⁴⁵ Most of these cements have much higher radiopacity values, between 6.53 and 7.17 mm of Al,⁵³,⁵⁴ up to 9 mm of Al.⁵⁵ In this study we observed that the minimum concentration of 10% of Bi₂O₃failed to obtain the 3 mm of Al necessary for clinical use, but with the concentration of 15% were obtained 4.3 mm of Al. However, the amount of bismuth in MTA cements has been shown to affect their physical properties. Compression resistance decreases, while porosity and solubility increase with higher concentrations of the radiopacifying agent.³⁰,⁵⁶ In the case of compression resistance and porosity, an inverse linear relationship between these two properties was observed, i.e. to higher porosity there was lower compression resistance. These properties are of clinical relevance because as is well known, the porosity of the material relates to its solubility⁵⁷ and results in greater degradation of the material, which compromises the clinical success of the restoration.

In the present study, we observed that adding between 10-15% of bismuth trioxide allows obtaining the radiopacity of 3 mm Al requested by ISO 6876, in agreement with Bueno et al.,⁵⁸ who suggest adding only 15% of the radiopacifying agent to maintain the best physical properties.

It should be noted that the physical properties of the materials are related to particle size. The use of bismuth trioxide particles of micrometric (10 μm) and nanometric (40-80 μm) size does not affect the radiopacity, but it does affect the resistance to compression and surface microhardness, which increase with the use of nanometric bismuth.⁵⁵ On the other hand, there is little evidence on the effect of bismuth trioxide on the hydration and setting process; it is only known that bismuth trioxide is not involved in the cement hydration process.⁵⁹,⁶⁰

The above mentioned physical properties of bismuth trioxide have been observed in isolation, but we should consider that regardless of the radiopacifying agent, calcium silicate cements possess the ability to produce apatites in an acellular environment, such as in contact with simulated bodily fluids.¹⁵,⁶¹,⁶² Thus, the possible failure in marginal adaptation due to material loss could be favored by the formation of apatites.

If we focus on the clinical part, color change has been observed in teeth restored with MTA.³⁶,³⁸,³⁹ Some studies mention a change to a grayish color of dental tissue,³⁷ which makes necessary a second clinical procedure to lighten the affected tooth. These changes in luminosity are given by the interaction between bismuth and collagen type I,⁴⁰ since dentin amino acids cause a sedimentation toward metal bismuth. During endodontic irrigation protocols, sodium hypochlorite is the most commonly used solution in different concentrations (0.5- 5.25%).⁶³-⁶⁵ The contact of the bismuth contained in the MTA with the sodium hypochlorite solution generates a dark brown-black pigmentation³⁵ due to a reduction of sodium hypochlorite to sodium chloride. This suggests that the higher the concentration of bismuth in cement, the greater the color change is in the dental structure.

Color change has not been observed with other bioceramic cements that use a radiopacifying agent other than bismuth trioxide, such as zirconium oxide,⁶⁶ which at 20% shows the same radiopacity as bismuth. There are also other materials, such as barium sulfate (BaSO₄), which is a radiopacifying agent used in resins and sealing cements in endodontics. Being white, it is expected that it will not suffer this pigmentation behavior, but when added at 20% concentration it does not show the radiopacity required, so it must be used at higher concentrations, which could affect its mechanical properties.⁶⁷ As for other radiopacifying agents, their biocompatibility and possible antimicrobial effect⁶⁸-⁷⁰ must be considered before use. It is important as well to evaluate these properties associated with different concentrations of bismuth trioxide.

Conclusions

The different amount of bismuth trioxide concentration in commercial cements can result in a different chemical and physical behavior than expected. An increased amount of the radiopacifying agent may cause lower resistance to compression and increased porosity and solubility, leading to decreased obturating capacity and thus higher chance of failure. The variation in concentration also affects the color stability of the restored tooth, creating black or grayish pigmentations. It is therefore important that quality control be maintained at the time of manufacturing commercial MTA cements with bismuth trioxide content.

Referencias / References

1. Torabinejad M, Hong C. Physical and chemical properties of a new root-end filling material. J Endod. 1995; 21 (7): 349- 353. [ Links ]

2. Simon S, Rilliard F, Berdal A, Machtou P. The use of mineral trioxide aggregate in one-visit apexification treatment: a prospective study. Int Endod J. 2007; 40 (3): 186-197. [ Links ]

3. Felippe W, Felippe M, Rocha M. The effect of mineral trioxide aggregate on the apexification and periapical healing of teeth with incomplete root formation. Int Endod J. 2006; 39 (1): 2-9. [ Links ]

4. Li Z, Cao L, Fan M, Xu Q. Direct pulp capping with calcium hydroxide or mineral trioxide aggregate: a meta-analysis. J Endod. 2015; 41 (9): 1412-1417. [ Links ]

5. Tuna D, Olmez A. Clinical long-term evaluation of MTA as a direct pulp capping material in primary teeth. Int Endod J. 2008; 41 (4): 273-278. [ Links ]

6. Unal G, Maden M, Isidan T. Repair of furcal iatrogenic perforation with mineral trioxide aggregate: two years follow-up of two cases. Eur J Dent. 2010; 4 (4): 475-481. [ Links ]

7. Arens DE, Torabinejad M. Repair of furcal perforations with mineral trioxide aggregate. Oral Surgery, Oral Med Oral Pathol Oral Radiol Endodontology [Internet]. 1996 Jul [cited 2015 Nov 19]; 82 (1): 84-88. Available from: Available from: http://www.sciencedirect.com/science/article/pii/S1079210496803829 . [ Links ]

8. Shipper G, Grossman ES, Botha AJ, Cleaton-Jones PE. Marginal adaptation of mineral trioxide aggregate (MTA) compared with amalgam as a root-end filling material: a low-vacuum (LV) versus high-vacuum (HV) SEM study. Int Endod J. 2004; 37 (5): 325-336. [ Links ]

9. Lee H, Shin Y, Kim S-O, Lee H-S, Choi H-J, Song JS. Comparative Study of Pulpal Responses to Pulpotomy with ProRoot MTA, RetroMTA, and TheraCal in Dogs’ Teeth. J Endod [Internet]. 2015 Aug [cited 2015 Nov 19]; 41 (8): 1317- 1324. Available from: Available from: http://www.sciencedirect.com/science/article/pii/S0099239915003428 . [ Links ]

10. De Rossi A, Silva LAB, Gatón-Hernández P, Sousa-Neto MD, Nelson-Filho P, Silva RAB et al. Comparison of pulpal responses to pulpotomy and pulp capping with biodentine and mineral trioxide aggregate in dogs. J Endod [Internet]. 2014; Sep [cited 2015 Oct 4]; 40 (9): 1362-1369. Available from: Available from: http://www.sciencedirect.com/science/article/pii/S0099239914001514 . [ Links ]

11. Mitchell PJ, Pitt Ford T, Torabinejad M, McDonald F. Osteoblast biocompatibility of mineral trioxide aggregate. Biomaterials [Internet]. 1999; Jan [cited 2015 Nov 19]; 20 (2): 167-173. Available from: Available from: http://www.sciencedirect.com/science/article/pii/S0142961298001574 . [ Links ]

12. Koh ET, McDonald F, Pitt Ford TR, Torabinejad M. Cellular response to mineral trioxide aggregate. J Endod. 1998; 24 (8): 543-547. [ Links ]

13. Maeda T, Suzuki A, Yuzawa S, Baba Y, Kimura Y, Kato Y. Mineral trioxide aggregate induces osteoblastogenesis via Atf6. Bone Reports [Internet]. 2015; Jun [cited 2015 Nov 19]; 2: 36-43. Available from: Available from: http://www.sciencedirect.com/science/article/pii/S2352187215000078 . [ Links ]

14. Gandolfi MG, Ciapetti G, Taddei P, Perut F, Tinti A, Cardoso MV et al. Apatite formation on bioactive calcium-silicate cements for dentistry affects surface topography and human marrow stromal cells proliferation. Dent Mater. 2010; 26 (10): 974-992. [ Links ]

15. Gandolfi MG, Taddei P, Tinti A, Prati C. Apatite-forming ability (bioactivity) of ProRoot MTA. Int Endod J. 2010; 43 (10): 917-929. [ Links ]

16. Gandolfi MG, Taddei P, Siboni F, Modena E, Marchetti C, Prati C. Apatite-type phases on MTA cements depend on soaking medium volume. Dent Mater [Internet]. 2011 Jan [cited 2015 Nov 19]; 27: e81-82. Available from: Available from: http://www.sciencedirect.com/science/article/pii/S010956411100813X . [ Links ]

17. Hakki SS, Bozkurt SB, Hakki EE, Belli S. Effects of mineral trioxide aggregate on cell survival, gene expression associated with mineralized tissues, and biomineralization of cementoblasts. J Endod. 2009; 35 (4): 513-519. [ Links ]

18. Zhou H, Shen Y, Wang Z, Li L, Zheng Y, Häkkinen L et al. In vitro cytotoxicity evaluation of a novel root repair material. J Endod. 2013; 39 (4): 478-483. [ Links ]

19. Dreger LAS, Felippe WT, Reyes-Carmona JF, Felippe GS, Bortoluzzi EA, Felippe MCS. Mineral trioxide aggregate and portland cement promote biomineralization in vivo. J Endod. 2012; 38 (3): 324-329. [ Links ]

20. Flores-Ledesma A, Barcelo SF, Bucio L, Arenas AJA. Elemental chemical composition and phase analysis by means of PIXE, DSC, TGA and XRD of MTA Angelus® and white Portland cement. Rev Odontológica Mex. 2016; 20 (3): 187-192. [ Links ]

21. Asgary S, Eghbal MJ, Parirokh M, Ghoddusi J, Kheirieh S, Brink F. Comparison of mineral trioxide aggregate’s composition with Portland cements and a new endodontic cement. J Endod. 2009; 35 (2): 243-250. [ Links ]

22. Parirokh M, Torabinejad M. Mineral trioxide aggregate: a comprehensive literature review--Part I: chemical, physical, and antibacterial properties. J Endod. 2010; 36 (1): 16-27. [ Links ]

23. Belío-Reyes IA, Bucio L, Cruz-Chavez E. Phase composition of ProRoot mineral trioxide aggregate by X-ray powder diffraction. J Endod. 2009; 35 (6): 875-878. [ Links ]

24. Park J-W, Hong S-H, Kim J-H, Lee S-J, Shin S-J. X-Ray diffraction analysis of white ProRoot MTA and Diadent BioAggregate. Oral Surg Oral Med Oral Pathol Oral Radiol Endod [Internet]. 2010; Jan [cited 2015 Nov 21]; 109 (1): 155-1558. Available from: Available from: http://www.sciencedirect.com/science/article/pii/S1079210409006593 . [ Links ]

25. Torabinejad M, Hong CU, McDonald F, Pitt Ford TR. Physical and chemical properties of a new root-end filling material. J Endod [Internet]. 1995; Jul [cited 2015 Nov 2]; 21 (7): 349-353. Available from: Available from: http://www.sciencedirect.com/science/article/pii/S0099239906809672 . [ Links ]

26. Kogan P, He J, Glickman GN, Watanabe I. The effects of various additives on setting properties of MTA. J Endod [Internet]. 2006; Jun [cited 2015 Nov 21]; 32 (6): 569-572. Available from: Available from: http://www.sciencedirect.com/science/article/pii/S0099239905000269 . [ Links ]

27. Lee BN, Hwang YC, Jang JH, Chang HS, Hwang IN, Yang SY et al. Improvement of the properties of mineral trioxide aggregate by mixing with hydration accelerators. J Endod [Internet]. 2011; 37 (10): 1433-1436. Available from: http://dx.doi.org/10.1016/j.joen.2011.06.013. [ Links ]

28. Huang T-H, Shie M-Y, Kao C-T, Ding S-J. The effect of setting accelerator on properties of mineral trioxide aggregate. J Endod [Internet]. 2008; 34 (5): 590-593. Available from: http://www.ncbi.nlm.nih.gov/pubmed/18436041. [ Links ]

29. Flores-Ledesma A, Barceló Santana F, Bucio L, Arenas- Alatorre JA, Faraji M, Wintergerst AM. Bioactive materials improve some physical properties of a MTA-like cement. Mater Sci Eng C. 2017; 71: 150-155. [ Links ]

30. Coomaraswamy KS, Lumley PJ, Hofmann MP. Effect of bismuth oxide radioopacifier content on the material properties of an endodontic Portland cement-based (MTA-like) system. J Endod. 2007; 33 (3): 295-298. [ Links ]

31. Viapiana R, Guerreiro-Tanomaru JM, Hungaro-Duarte MA, Tanomaru-Filho M, Camilleri J. Chemical characterization and bioactivity of epoxy resin and Portland cement-based sealers with niobium and zirconium oxide radiopacifiers. Dental Materials. 2014; 30 (9): 1005-1020. [ Links ]

32. Grazziotin-Soares R, Nekoofar MH, Davies TE, Bafail A, Alhaddar E, Hübler R et al. Effect of bismuth oxide on white mineral trioxide aggregate: chemical characterization and physical properties. Int Endod J. 2014; 47 (6): 520-533. [ Links ]

33. Cutajar A, Mallia B, Abela S, Camilleri J. Replacement of radiopacifier in mineral trioxide aggregate; characterization and determination of physical properties. Dent Mater. 2011; 27 (9): 879-891. [ Links ]

34. Islam I, Kheng Chng H, Jin Yap AU. Comparison of the physical and mechanical properties of MTA and portland cement. J Endod. 2006; 32 (3): 193-197. [ Links ]

35. Camilleri J. Color stability of white mineral trioxide aggregate in contact with hypochlorite solution. J Endod. 2014; 40 (3): 436-440. [ Links ]

36. Bortoluzzi EA, Araújo GS, Guerreiro Tanomaru JM, Tanomaru-Filho M. Marginal gingiva discoloration by gray MTA: a case report. J Endod. 2007; 33 (3): 325-327. [ Links ]

37. Belobrov I, Parashos P. Treatment of tooth discoloration after the use of white mineral trioxide aggregate. J Endod. 2011; 37 (7): 1017-1020. [ Links ]

38. Felman D, Parashos P. Coronal tooth discoloration and white mineral trioxide aggregate. J Endod. 2013; 39 (4): 484-487. [ Links ]

39. Jang J-H, Kang M, Ahn S, Kim S, Kim W, Kim Y et al. Tooth discoloration after the use of new pozzolan cement (Endocem) and mineral trioxide aggregate and the effects of internal bleaching. J Endod. [Internet]. 2013; 39 (12): 1598-1602. Available from: http://www.ncbi.nlm.nih.gov/pubmed/24238455. [ Links ]

40. Marciano MA, Costa RM, Camilleri J, Mondelli RFL, Guimarães BM, Duarte MAH. Assessment of color stability of white mineral trioxide aggregate angelus and bismuth oxide in contact with tooth structure. J Endod. 2014; 40 (8): 1235-1240. [ Links ]

41. Camilleri J. Staining Potential of Neo MTA Plus, MTA Plus, and biodentine used for pulpotomy procedures. J Endod [Internet]. 2015. Jul [cited 2015 Nov 8]; 41 (7): 1139-1145. Available from: Available from: http://www.sciencedirect.com/science/article/pii/S0099239915002101 . [ Links ]

42. Kang S-H, Shin Y-S, Lee H-S, Kim S-O, Shin Y, Jung I-Y et al. Color changes of teeth after treatment with various mineral trioxide aggregate-based materials: an ex vivo study. J Endod. 2015; 41 (5): 737-741. [ Links ]

43. Islam I, Chng HK, Yap AUJ. Comparison of the root-end sealing ability of MTA and Portland cement. Aust Endod J. 2005; 31 (2): 59-62. [ Links ]

44. Moreno-Vargas YA, Luna-Arias JP, Flores-Flores JO. Hydration reactions and physicochemical properties in a novel tricalcium-dicalcium silicate-based cement containing hydroxyapatite nanoparticles and calcite: a comparative study. Ceram Int. 2017; 43: 13290-13298. [ Links ]

45. ISO. Specification for dental root canal sealing materials. ISO 6876. London; 2011. [ Links ]

46. Shojaee N, Adl A, Jafarpur D, Sobhnamayan F. Effect of different water-to-powder ratios on the compressive strength of calcium-enriched mixture. Iran Endod J. 2018; 13 (3): 395-397. [ Links ]

47. Fridland M, Rosado R. MTA solubility: long tern study. J Endod. 2005; 31: 376-379. [ Links ]

48. Vivan RR, Ordinola-Zapata R, Bramante CM, Bernardineli N, Garcia RB, Hungaro Duarte MA et al. Evaluation of the radiopacity of some commercial and experimental root-end filling materials. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009; 108 (6): e35-8. [ Links ]

49. Torabinejad M, White DJ. Tooth filling material and method of use. Washington, DC: United States Patent & Trademark Office; Patent Number 5,769,638, May 16, 1995. [ Links ]

50. Húngaro Duarte MA, de Oliveira El Kadre GD, Vivan RR, Guerreiro Tanomaru JM, Filho MT, de Moraes IG. Radiopacity of portland cement associated with different radiopacifying agents. J Endod. 2009; 35 (5): 737-740. [ Links ]

51. Sureshchandra B, Gopikrishna V. Grossman’s endodontic practice. 13th Edition. Ser, editor. India: Wolter Kluwer Health; 2014. p. 343. [ Links ]

52. Ørstavik D. Materials used for root canal obturation: technical, biological and clinical testing. Endod Top. [Internet]. 2005; 12 (1): 25-38. Available from: http://doi.wiley.com/10.1111/j.1601-1546.2005.00197.x. [ Links ]

53. Torabinejad M, Hong C. Physical and chemical properties of a new root-end filling material. J Endod. 1995; 27 (1): 349-353. [ Links ]

54. Hwang YC, Lee SH, Hwang IN, Kang IC, Kim MS, Kim SH et al. Chemical composition, radiopacity, and biocompatibility of Portland cement with bismuth oxide. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009; 107 (3): e96-102. [ Links ]

55. Saghiri MA, Gutmann JL, Orangi J, Asatourian A, Sheibani N. Radiopacifier particle size impacts the physical properties of tricalcium silicate-based cements. J Endod [Internet]. 2015; Feb [cited 2015 Nov 21]; 41 (2): 225-230. Available from: Available from: http://www.sciencedirect.com/science/article/pii/S0099239914009303 . [ Links ]

56. Formosa LM, Mallia B, Bull T, Camilleri J. The microstructure and surface morphology of radiopaque tricalcium silicate cement exposed to different curing conditions. Dent Mater [Internet]. 2012 May [cited 2015 Nov 19]; 28 (5): 584-595. Available from: Available from: http://www.sciencedirect.com/science/article/pii/S0109564112000504 . [ Links ]

57. Fridland M, Rosado R. Mineral trioxide aggregate (MTA) solubility and porosity with different water-to-powder ratios. J Endod. 2003; 29 (12): 814-817. [ Links ]

58. Bueno CE d S, Zeferino EG, Manhaes JLRC, Rocha DGP, Cunha RS, De Martin AS. Study of the bismuth oxide concentration required to provide Portland cement with adequate radiopacity for endodontic use. Oral Surgery, Oral Med Oral Pathol Oral Radiol Endodontology [Internet]. 2009; 107 (1): e65-59. Available from: http://dx.doi.org/10.1016/j.tripleo.2008.09.016. [ Links ]

59. Camilleri J. Hydration mechanisms of mineral trioxide aggregate. Int Endod J. 2007; 40 (6): 462-470. [ Links ]

60. Camilleri J, Sorrentino F, Damidot D. Investigation of the hydration and bioactivity of radiopacified tricalcium silicate cement, Biodentine and MTA Angelus. Dent Mater [Internet]. 2013; May [cited 2015 Nov 19]; 29 (5): 580-593. Available from: Available from: http://www.sciencedirect.com/science/article/pii/S0109564113000559 . [ Links ]

61. Coleman NJ, Nicholson JW, Awosanya K. A preliminary investigation of the in vitro bioactivity of white Portland cement. Cem Concr Res. 2007; 37 (11): 1518-1523. [ Links ]

62. Abd Rashid R, Shamsudin R, Abdul Hamid MA, Jalar A. In-vitro bioactivity of wollastonite materials derived from limestone and silica sand. Ceram Int. 2014; 40 (5): 6847-6853. [ Links ]

63. Cárdenas-Bahena Á, Sánchez-García S, Tinajero-Morales IIC, González-Rodríguez VM, Baires-Várguez L. Hipoclorito de sodio en irrigación de conductos radiculares: sondeo de opinión y concentración en productos comerciales. [Use of sodium hypochlorite in root canal irrigation. Opinion survey and concentration in commercial products]. Rev Odontológica Mex. 2012; 16 (4): 252-258. [ Links ]

64. Del Castillo G, Perea B, Labajo E, Santiago A, Garcia F. Lesiones por hipoclorito sódico en la clínica odontológica: causas y recomendaciones de actuación. Científica Dent. 2011; 8 (1): 71-79. [ Links ]

65. Siqueira JF, Rqas N, Favieri A. Chemomechanical reduction of the bacterial and irrigation with 1%, 2.5%, and 5.25% sodium population in the root canal after instrumentation hypochlorite. J Endod. 2000; 26 (6): 331-334. [ Links ]

66. Beatty H, Svec T. Quantifying coronal tooth discoloration caused by biodentine and endosequence root repair material. J Endod. 2015; 41 (12): 2036-2039. [ Links ]

67. Bortoluzzi EA, Guerreiro-Tanomaru JM, Tanomaru-Filho M, Duarte MAH. Radiographic effect of different radiopacifiers on a potential retrograde filling material. Oral Surgery, Oral Med Oral Pathol Oral Radiol Endodontology [Internet]. 2009; 108 (4): 628-632. Available from: http://dx.doi.org/10.1016/j.tripleo.2009.04.044. [ Links ]

68. Vega-Jiménez AL, Almaguer-Flores A, Flores-Castaneda M, Camps E, Uribe-Ramirez M, Aztatzi-Aguilar OG et al. Bismuth subsalicylate nanoparticles with anaerobic antibacterial activity for dental applications. Nanotechnology. 2017; 28 (43): 1-12. [ Links ]

69. Campos V, Almaguer-Flores A, Velasco-Aria D, Díaz D, Rodil SE. Bismuth and silver nanoparticles as antimicrobial agent over subgingival bacterial and nosocomial strains. J Mater Sci Eng A. 2018; 8 (7-8): 142-146. [ Links ]

70. Hernandez-Delgadillo R, Del Angel-Mosqueda C, Solís- Soto JM, Munguia-Moreno S, Pineda-Aguilar N, Sánchez-Nájera RI et al. Antimicrobial and antibiofilm activities of MTA supplemented with bismuth lipophilic nanoparticles. Dent Mater J [Internet]. 2017; 36 (4): 503-510. Available from: https://www.jstage.jst.go.jp/article/dmj/36/4/36_2016-259/_article. [ Links ]

Received: August 01, 2018; Accepted: April 01, 2019

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