| Abstract|| |
Endodontic treatments have as their objective the appropriate sealing of the space caused by the root canal, providing a complete seal of the canal in all dimensions, creating an airtight seal against fluids. Thus, endodontic cements must possess physical properties such as solubility and long-term dimensional stability. An electronic search in the main endodontic magazines using appropriate keywords to identify studies that investigated the porosity of endodontic materials using micro-computed tomography. Of the 125 studies researched, 16 fulfilled the criteria for inclusion. Four studies analyzed the porosity of endodontic cements specifically. Twelve studies investigated and compared different techniques of root canal obturation and the repercussions from the lowering of porosity in the interior of the endodontic cement. The presence of porosity inside the endodontic cement is a constant in the treatments of root canals, even now when there is a great variety of endodontic cements.
Keywords: Endodontic sealer; microcomputed tomography; porosity; root canal filling materials; root canal obturation
|How to cite this article:|
Ortiz FG, Jimeno EB. Analysis of the porosity of endodontic sealers through micro-computed tomography: A systematic review. J Conserv Dent 2018;21:238-42
|How to cite this URL:|
Ortiz FG, Jimeno EB. Analysis of the porosity of endodontic sealers through micro-computed tomography: A systematic review. J Conserv Dent [serial online] 2018 [cited 2018 Jun 19];21:238-42. Available from: http://www.jcd.org.in/text.asp?2018/21/3/238/232935
| Introduction|| |
Among the principle key to the success of endodontic treatment is the sealing in an appropriate manner the root canal. The sealing of a root canal has historically been achieved with gutta-percha and a sealer, the goal being to completely seal the canal in all dimensions, creating an airtight seal against fluids and avoiding the entrance of bacteria, toxins, and their flow toward the periapical tissues. Therefore, it is important that sealing and repairing cements possess certain physical properties, such as solubility and long-term dimensional stability. There are studies that have analyzed that the solubility of a duct-sealing material is in permanent relationship with the porosity that this material may have. The porosity and other defects of the microstructure of the endodontic sealant can produce foci of structural weakness and tensile strength of the material, producing microcracks.
Microcracks are defined as a decrease in the partial or total strength of a sealant, which can cause leakage within the endodontic cement in the root canal. Therefore, when we use the term pores when we speak of an endodontic material, we refer to the interaction between its physical properties and the type of mixture that was used to produce the material. Sealing or duct repair materials that are mixed manually according to the studies that have been made are more prone to subjective factors induced by the operator, thus producing more structural defects.,
Micro-computed tomography (micro-CT) creates nondestructive three-dimensional (3D) images utilized to evaluate the microstructure, morphology, density of the mineralized tissues, and the internal structure.
In endodontics, micro-CT has been used to evaluate the anatomy of root canals, their geometry, or shape to estimate the morphology of the dental root in addition to the spatial details after the instrumentation of the root canal. Another use of micro-CT in endodontics is to analyze the volume of pores inside endodontic cements,,, and for the comparison of various obturation techniques that help to reduce the amount of pores in endodontic cements inside of the root canal.,,,,,,,,,,,
| Methodology of Publication Search|| |
An electronic search was made of the database PubMed (https://www.ncbi.nlm.nih.gov/pubmed/), Scopus (https://www.scopus.com) to identify the studies related to the evaluation of the porosity of different endodontic cements using micro-CT images. The following keywords were used: “Micro-CT” and “porosity” and “root canal filling materials” or “root canal obturation” or “endodontic sealer” and “obturation techniques.” The search was limited to publications written in English. A manual electronic search was also carried out for the following main endodontic magazines: Journal of Dental Research; Dental Materials; Journal of Dentistry; Journal of Endodontics; International Endodontic Journal; The Journal of the American Dental Association; European Journal of Oral Sciences; and Australian Endodontic Journal. The following keywords were used for this search: “Micro-CT” and “endodontic sealer” and “porosity.” The search included articles from the start of each publication up to November 30, 2017. After the elimination of duplicate articles and reviewing the titles and summaries, full-text articles were used to verify that the content of the article was relevant.
| Results|| |
Following the elimination of duplicate articles, the electronic search strategy produced 125 publications. The initial selection of the studies was done using the titles and summaries. However, when the suitability of an article was not clear, then the entire text was read. The writers evaluated the studies independently and discussed the results. Of the 125 studies found, 16 fit the criteria [Figure 1].
| Discussion|| |
Using microcomputed tomography to evaluate porosity
In the characterization of dental materials, micro-CT has gained much popularity due to its 3D nature and that it is not destructive, leaving the material intact following the analysis. Although micro-CT is widely used for the characterization of porous materials, the accuracy and reliability of this method still require more quantifying.
Analysis of the porosity of endodontic cements
Research and scientific publications that study only the porosity of endodontic obturation materials by means of micro-CT analysis present a reduced number of articles on this specific topic. We find references to Mokeem-Saleh and Mokeem et al., and their research that has analyzed the porosity of endodontic cements, which find that endodontic sealers produce a level of porosity depending on the composition of the endodontic cement and some cements present a higher volume of porosity than others. In addition, all of the researchers who analyzed the porosity of specific endodontic cements in vitro affirm that there is no material that is 100% free of porosity.,,,
A study performed with ProRoot ® MTA y MTA Angelus ®, in which the porosity of those endodontic materials was analyzed in vitro, found that there is no statistically significant difference between the two materials.
When comparing the following endodontic cements in a study in vitro, iRoot BP Plus ®, Biodentine ®, Ceramicrete-D, ProRoot ® MTA, the researchers found that iRoot BP Plus ® has the highest porosity and Ceramicrete-D is the endodontic cement with the least porosity. [Table 1].
|Table 1: Studies that reviewed the porosity of endodontic materials using micro-computed tomography analysis|
Click here to view
Analysis of the porosity of endodontic cements according to the obturation technique
In reference to the obturation technique applied at the moment of sealing a root canal, there are various in vitro studies that evaluate the porosity of the root canal through micro-CT, reporting similar findings among all of the analyzed studies in that of all the obturation materials and techniques used, there is not a single result that presents the absence of pores in the interior of the canal.,,,,,,,,,,,,,
The endodontic cement most analyzed, applying diverse obturation techniques according to the different studies analyzed in this systematic review, is AH Plus ®.,,,,,,, In the study by Gandolfi et al., MTA Flow™ was compared with AH Plus ® using Thermafil ® as the obturation technique and the study concluded that MTA Flow™ produced less porosity at the time of sealing the root canal. However, in another study that analyzed the porosity of the material when using the lateral condensation technique with BioRoot™ RCS and AH Plus ®, the results showed that BioRoot™ RCS produced greater porosity than AH Plus ®.
An in vitro study compared MTA Angelus ® and ProRoot ® MTA using different mixing techniques and condensation, showing that MTA Angelus ® presents a higher quantity of pores than ProRoot ® MTA and also that the mechanical mixing technique and indirect ultrasonic activation were the methods that produced the lowest amount of pores in root canals.
Among the various techniques available to seal the root canal, the lateral condensation technique, use of a single cone, and vertical compaction are the ones that obtain the best results when the porosity is measured using micro-CT, depending on the obturation material being applied.,,, There are other techniques that cannot be compared with the aforementioned since there is no in vitro scientific study to compare them. However, based on the results of the recently mentioned studies, we can say that the techniques BeeFill ®, Thermafil ®, and ReaSeal 1™ contribute to a reduction of porosity.,,, In addition, there are other materials such as RoekoSeal ® y Tubli-Seal™ Ewt that show a reduced volume of pores in the interior of said endodontic cements , [Table 2].
|Table 2: Studies that investigate the porosity of endodontic materials according to the obturation technique employed using micro-computed tomography|
Click here to view
| Conclusions|| |
The use of different obturation techniques and the wide variety of endodontic cements with varied compositions available currently allow us to lower substantially the presence of porosity in the interior of the root canal, but there does not exist any technique nor any endodontic material that eliminates porosity completely when performing an endodontic treatment.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Epley SR, Fleischman J, Hartwell G, Cicalese C. Completeness of root canal obturations: Epiphany techniques versus gutta-percha techniques. J Endod 2006;32:541-4.
Özok A, Van der Sluis L, Wu M, Wesselink P, Xu Q, Fan M, et al
. Sealing ability of a new polydimethylsiloxane-based root canal filling material. J Endod 2008;34:204-7.
Mokeem-Saleh A, Hammad M, Silikas N, Qualtrough A, Watts DC. A laboratory evaluation of the physical and mechanical properties of selected root canal sealers. Int Endod J 2010;43:882-8.
Mutal L, Gani O. Presence of pores and vacuoles in set endodontic sealers. Int Endod J 2005;38:690-6.
De-Deus G, Scelza MZ, Neelakantan P, Sharma S, Neves Ade A, Silva EJ, et al.
Three-dimensional quantitative porosity characterization of syringe- versus hand-mixed set epoxy resin root canal sealer. Braz Dent J 2015;26:607-11.
Almeida JF, Gomes BP, Ferraz CC, Souza-Filho FJ, Zaia AA. Filling of artificial lateral canals and microleakage and flow of five endodontic sealers. Int Endod J 2007;40:692-9.
Sisli SN, Ozbas H. Comparative micro-computed tomographic evaluation of the sealing quality of proRoot MTA and MTA angelus apical plugs placed with various techniques. J Endod 2017;43:147-51.
Duque JA, Fernandes SL, Bubola JP, Duarte MA, Camilleri J, Marciano MA, et al.
The effect of mixing method on tricalcium silicate-based cement. Int Endod J 2018;51:69-78.
Nazarian A, Snyder BD, Zurakowski D, Müller R. Quantitative micro-computed tomography: A non-invasive method to assess equivalent bone mineral density. Bone 2008;43:302-11.
Ordinola-Zapata R, Martins JN, Bramante CM, Villas-Boas MH, Duarte MH, Versiani MA, et al.
Morphological evaluation of maxillary second molars with fused roots: A micro-CT study. Int Endod J 2017;50:1192-200.
Mokeem A, Hammad M, Silikas N, Watts D. Micro-CT evaluation of porosity in set endodontic sealers. Dent Mater 2009;25:16.
Basturk 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.
De Souza ET, Nunes Tameirão MD, Roter JM, De Assis JT, De Almeida Neves A, De-Deus GA, et al.
Tridimensional quantitative porosity characterization of three set calcium silicate-based repair cements for endodontic use. Microsc Res Tech 2013;76:1093-8.
Can E, Keleş A, Aslan B. Evaluation of the root filling quality of three root canal filling systems with micro-CT. Int Endod J 2016;18:155-61.
Celikten B, Uzuntas CF, Orhan AI, Orhan K, Tufenkci P, Kursun S, et al.
Evaluation of root canal sealer filling quality using a single-cone technique in oval shaped canals: An in vitro
micro-CT study. Scanning 2016;38:133-40.
Moinzadeh AT, Zerbst W, Boutsioukis C, Shemesh H, Zaslansky P. Porosity distribution in root canals filled with gutta percha and calcium silicate cement. Dent Mater 2015;31:1100-8.
Viapiana 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.
Keleş A, Alcin H, Kamalak A, Versiani MA. Micro-CT evaluation of root filling quality in oval-shaped canals. Int Endod J 2014;47:1177-84.
Wolf M, Küpper K, Reimann S, Bourauel C, Frentzen M. 3D analyses of interface voids in root canals filled with different sealer materials in combination with warm gutta-percha technique. Clin Oral Investig 2014;18:155-61.
Naseri 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.
El-Ma'aita AM, Qualtrough AJ, Watts DC. A micro-computed tomography evaluation of mineral trioxide aggregate root canal fillings. J Endod 2012;38:670-2.
Gandolfi MG, Parrilli AP, Fini M, Prati C, Dummer PM. 3D micro-CT analysis of the interface voids associated with thermafil root fillings used with AH plus or a flowable MTA sealer. Int Endod J 2013;46:253-63.
Anbu R, Nandini S, Velmurugan N. Volumetric analysis of root fillings using spiral computed tomography: An in vitro
study. Int Endod J 2010;43:64-8.
Hammad M, Qualtrough A, Silikas N. Evaluation of root canal obturation: A three-dimensional in vitro
study. J Endod 2009;35:541-4.
Swain MV, Xue J. State of the art of micro-CT applications in dental research. Int J Oral Sci 2009;1:177-88.
Economides N, Panagiotis B, Kolokouris I, Gogos C, Kokorikos I. Comparative study of the sealing ability of a polydimethylsiloxane-based root canal sealer. Braz Dent J 2005;16:145-8.
Zogheib C, Naaman A, Sigurdsson A, Medioni E, Bourbouze G, Arbab-Chirani R, et al.
Comparative micro-computed tomographic evaluation of two carrier-based obturation systems. Clin Oral Investig 2013;17:1879-83.
Dr. Fabricio Guerrero Ortiz
Department of Odontostomatology, School of Dentistry, University of Barcelona, Barcelona
Source of Support: None, Conflict of Interest: None
[Table 1], [Table 2]