Journal of Conservative Dentistry

ORIGINAL ARTICLE
Year
: 2018  |  Volume : 21  |  Issue : 5  |  Page : 491--494

Porosity analysis of mineral trioxide aggregate Fillapex and BioRoot cements for use in endodontics using microcomputed tomography


Fabricio Guerrero1, Esther Berástegui1, Karla Aspiazu2,  
1 Department of Odonto-Stomatology, Faculty of Dentistry, University of Barcelona, Barcelona, Spain
2 Department of Research, School of Medicine, Catholic University of Cuenca, Cuenca, Ecuador

Correspondence Address:
Dr. Fabricio Guerrero
Department of Odonto-Stomatology, School of Dentistry, University of Barcelona, Barcelona
Spain

Abstract

Aim: The purpose of this study is to compare the porosity of two sealant cements, mineral trioxide aggregate (MTA) Fillapex® and BioRoot® root canal sealer (RCS). These samples were analyzed using microcomputed tomography. Materials and Methods: Sixteen samples were used in the study that were divided according to the composition of the materials used. MTA Fillapex® (n = 8) and BioRoot® RCS (n = 8) were the samples prepared according to the manufacturer's instructions. They were placed in silicone molds of 5 ± 0.1 mm in height and an internal diameter of 5 ± 0.1 mm; 24 h after its preparation, the samples were scanned through a microcomputed tomography, and the porosity results were analyzed statistically by independent t-tests. Results: It is evident that MTA Fillapex® has better porosity properties than BioRoot® RCS. The results of the study quantify a smaller number of pores per surface, a smaller volume in each pore per mm3, and a lower total porosity present in samples of MTA Fillapex® unlike BioRoot® RCS samples which is larger in both. Conclusions: The results obtained in computerized microtomography endodontic biomaterial samples concluded that MTA Fillapex® has a lower porosity than BioRoot® RCS.



How to cite this article:
Guerrero F, Berástegui E, Aspiazu K. Porosity analysis of mineral trioxide aggregate Fillapex and BioRoot cements for use in endodontics using microcomputed tomography.J Conserv Dent 2018;21:491-494


How to cite this URL:
Guerrero F, Berástegui E, Aspiazu K. Porosity analysis of mineral trioxide aggregate Fillapex and BioRoot cements for use in endodontics using microcomputed tomography. J Conserv Dent [serial online] 2018 [cited 2020 Jul 14 ];21:491-494
Available from: http://www.jcd.org.in/text.asp?2018/21/5/491/241193


Full Text

 Introduction



Basically, there are three causes for the existence of microfiltration: the first is the interface between the sealant and core material, the second is the interface between the sealant and the dentin wall, and the third cause of microfiltration is within the endodontic cement itself, that is, the porosity that the endodontic material presents. Corono-apical and apico-coronal filtration may be the form of the distribution of this filtration. The percentage of entry of microorganisms in the endodontic material would also be influenced by the pore distribution, size, and connectivity between them. In addition, the porosity is directly influenced by relating it to the microfiltration behavior of the obturation material of the root canal, and as a consequence, it will be related to the solubility.[1]

The techniques that have been used in the past to verify the porosity of the duct filling material [2] are complex and difficult to reproduce.[3] Unlike techniques that are being used as mercury perfusion,[4] porosimetry with adsorption isotherms / nitrogen desorption,[5] which allows the reproducibility of studies, there is currently a new technique that It is the computed tomography (micro-CT). It is a three-dimensional imaging technique that leaves the sample intact and is being used as an alternative means to determine the porosity of a biomaterial.[6]

 Materials and Methods



In this in vitro study, silicone tubes were used as molds to place the repair materials (n = 16); each silicone mold had a height of 5 ± 0.1 mm and an internal diameter of 5 ± 0.1 mm, filled with mineral trioxide aggregate (MTA) Fillapex ® (n = 8), and the other sealant cement used was BioRoot ® root canal sealer (RCS) (n = 8). All samples were prepared by a single operator following the manufacturer's instructions for powder-to-liquid ratios, preparation time, and setting time.

Sample preparation

The silicone molds were proceeded to clean the internal part that is empty and were placed on a glass plate. Subsequently, a repair cement was mixed, until the eight samples per group were made according to the material used, in which the endodontic cement was placed by means of an amalgam holder and a metal spatula to fill the silicone molds; this procedure was repeated in each sample of the two materials that were analyzed in the present study. We waited for 24 h by which the materials merged completely according to the indications of the manufacturers before passing to the analysis by means of the micro-CT (SkyScan 1174, Bruker micro-CT, Kontich, Belgium). The silicone mold was not removed from repairing cements because being a material that allows the passage of X-rays that produce the micro-CT does not influence or alter the study. In each sample that was found to be defective due to voids in the repair material in the silicone mold, the sample showing the defect was removed and replaced with a new sample.

Scanning of microcomputed tomography

The samples were scanned using a micro-CT (SkyScan 1174, Bruker micro-CT, Kontich, Belgium). The following scan parameters were applied: 50 kV and 800 μA voltage source, 9.6 μm pixel size, 0.80° rotation to achieve 180° total rotation and exposure time of 16,000 ms. Using NRecon software (Skyscan), the 450 images obtained from the scan were reconstructed to show two-dimensional slices of the internal structure of the MTA Fillapex ® and BioRoot ® RCS samples. Three-dimensional reconstruction, volumetric analysis, and measurement of the pore volume were analyzed using CTan and CTVol (Bruker SkyScan, Belgium) software of 450 cross-sections of each sample.

Statistical analysis

The porosity values present in the endodontic repair cement samples analyzed in the study were compared using the Student's “t-” tests for independent samples (SPSS version 24.0, SPSS Inc., Chicago, IL, USA). P < 0.05 was considered statistically significant.

 Results



Through the sagittal and transverse sections of the samples [Figure 1], it was possible to quantify the volume of each pore per mm 3, the number of pores per surface, and the total porosity present in the endodontic materials, both based on MTA and based on calcium silicate [Table 1] and [Table 2].{Figure 1}{Table 1}{Table 2}

It has been found that the repair material based on MTA Fillapex ® has better properties in regard to porosity unlike the material based on calcium silicate BioRoot ® RCS, since the results of MTA Fillapex ® in what refers to the amount of pores per surface are notably lower than those presented by BioRoot ® RCS (P = 0.000). In addition, the volume of each pore per mm 3 in MTA Fillapex ® is smaller in volume than the MTA (P = 0.006) and the total porosity is also smaller in MTA Fillapex ® (P = 0.051).

 Discussion



In the characterization of dental materials, the micro-CT has obtained much popularity, by not altering or destroying the sample analyzed, and its innovative three-dimensional technology.[7] Although the micro-CT is widely used for the characterization of porous materials, the precision and reliability of this method still require a greater specialization.[8]

The use of computed microtomography in the area of endodontics has been one of the specialties in which the micro-CT is being used since the endodontic materials can be evaluated, as well as the techniques of duct filling.[7],[9]

In a study conducted by Viapiana et al.[10] in which they investigated the ability of BioRoot ® RCS and AH Plus ® to effectively seal the root canals in an ex vivo study using a micro-CT, the results showed that BioRoot ® RCS had more percentage of porosity than AH Plus ® in a significant way. BioRoot ® RCS exhibited a different pattern of sealing penetration and interaction with dentin walls compared to AH Plus ®. In the same way, it happened in the present study in relation to BioRoot ® and the porosity within the material analyzed by means of a micro-CT, since MTA Fillapex ® presented less porosity when compared with BioRoot ®. They reaffirm Camilleri et al.[11] who evaluated the porosity of four endodontic materials, BioRoot ® RCS, Biodentine ®, a prototype of tricalcium silicate cement (TCS-20-Zr) and an intermediate restorative material (IRM); the porosity was measured using mercury intrusion porosimetry. The results determined that Biodentine ® and IRM exhibited the lowest levels of porosity in the aforementioned endodontic materials.

With regard to studies carried out on porosity by means of a micro-CT analyzing the MTA Fillapex ® endodontic cement, we have not known so far any study in the scientific literature, with which we can compare the results obtained in the present study. However, there are studies carried out using mercury intrusion porosimetry, as in the case of the study conducted by Marciano et al.[12] who investigated the porosity of calcium silicate-based sealants. They prepared experimental sealers based on the calcium silicate with calcium tungstate and zirconium oxide radiopacifiers by mixing 1 g of powder to 0.3 ml of 80% distilled water and 20% propylene glycol. MTA Angelus ® and MTA Fillapex ® were used as controls. The results concluded that the prototype sealants showed a percentage porosity similar to MTA, but that MTA Fillapex ® exhibited the lowest porosity of all the sealants analyzed in the study. In the same way, Gomes et al.[13] investigated the physical characterization of porosity in MTA Fillapex ® endodontic sealants, AH Plus ®, Sealer 26®, and Endofill ®. Using the technique of analysis of porosity by intrusion of mercury. The porosimetry showed that the MTA Fillapex ® had the best results with a lower porosity than the other sealing materials. Sealer 26® showed the highest porosity among the cements analyzed.

 Conclusions



Within the limitations presented by the in vitro study, and considering the results of the analysis of the images obtained through the micro-CT in the samples of the repairing cements with regard to porosity, it is observed that the repair cement MTA Fillapex ® presents less porosity compared to the porosity present in BioRoot ® RCS.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Saghiri MA, Lotfi M, Saghiri AM, Vosoughhosseini S, Fatemi A, Shiezadeh V, et al. Effect of pH on sealing ability of white mineral trioxide aggregate as a root-end filling material. J Endod 2008;34:1226-9.
2Torabinejad M, Parirokh M. Mineral trioxide aggregate: A comprehensive literature review – Part II: Leakage and biocompatibility investigations. J Endod 2010;36:190-202.
3Wu MK, Wesselink PR. Endodontic leakage studies reconsidered. Part I. Methodology, application and relevance. Int Endod J 1993;26:37-43.
4Formosa LM, Damidot D, Camilleri J. Mercury intrusion porosimetry and assessment of cement-dentin interface of anti-washout-type mineral trioxide aggregate. J Endod 2014;40:958-63.
5Westermarck S. Use of Mercury Porosimetry and Nitrogen Adsorption in Characterisation of the Pore Structure of Mannitol and Microcrystaline Cellulose Powders, Granules and Tablets. Finland: University of Helsinki; 2000.
6Basturk FB, Nekoofar MH, Gunday M, Dummer PM. Effect of various mixing and placement techniques on the flexural strength and porosity of mineral trioxide aggregate. J Endod 2014;40:441-5.
7Swain MV, Xue J. State of the art of micro-CT applications in dental research. Int J Oral Sci 2009;1:177-88.
8Naseri M, Kangarlou A, Khavid A, Goodini M. Evaluation of the quality of four root canal obturation techniques using micro-computed tomography. Iran Endod J 2013;8:89-93.
9Ahmed HM. Nano-computed tomography: Current and future perspectives. Restor Dent Endod 2016;41:236-8.
10Viapiana R, Moinzadeh AT, Camilleri L, Wesselink PR, Tanomaru Filho M, Camilleri J, et al. Porosity and sealing ability of root fillings with gutta-percha and bioRoot RCS or AH plus sealers. Evaluation by three ex vivo methods. Int Endod J 2016;49:774-82.
11Camilleri J, Grech L, Galea K, Keir D, Fenech M, Formosa L, et al. Porosity and root dentine to material interface assessment of calcium silicate-based root-end filling materials. Clin Oral Investig 2014;18:1437-46.
12Marciano MA, Duarte MA, Camilleri J. Calcium silicate-based sealers: Assessment of physicochemical properties, porosity and hydration. Dent Mater 2016;32:e30-40.
13Gomes A, Antônio R, José do Nascimento A, Lobianco S. Analysis of the Porosimetry of the Cement MTA-Fillapex Compared with AH Plus, Sealer 26 and Endofill. Angelus. Available from: http://www.angelus.ind.br/medias/1504011007_CC0004-ING. [Last accessed on 2018 Mar 14].