## 4 Discussion
This was confirmed by SEM photographs, which found more adaptation of MTA Fillapex to the root canal wall under all magnifications. AH Plus is an epoxy resin sealer with proper flowability and viscosity, which may help provide a higher degree of penetration. It etches the dentinal surface, exposes collagens, and results in a more efficient attachment to the dentinal walls [34]. [PERSON] et al. [35] compared the marginal matching of MTA Fillapex, AH Plus, and Endofill. They showed that the greatest marginal matching capacity was shown with AH Plus, followed by Endofill and MTA Fillapex. The lowest microleakage of the AH Plus sealer may be due to its better marginal matching, better tubular penetration, and weak acidity [36; 37]. The difference between our study and that of [PERSON] et al. [35] may be due to the results provided by [PERSON] et al. [28], who stated that the best bond strength can be achieved by using 7% maleic acid as the final irrigant for the best bonding results with AH Plus sealer, while the final irrigant in our study was EDTA, which was proven by [PERSON] et al. [28] to give the best bonding results with MTA-based sealers. AH Plus has superior penetration into the micro irregularities that increases the mechanical interlocking between the dentin and the sealer because of its great capacity to creep and the long setting time unlike other bio-ceramic sealers which creates a chemo-mechanical bond with the root dentin [35; 36; 37; 38]. That may be because of the hydrophobicity and the likelihood of shrinkage for AH Plus. The gutta-percha/AH Plus sealer interface is highly hydrophobic [39; 40], and while the dentin is hydrophilic, the dentin/sealer interface is rather hydrophilic, creating gaps that act as major pathways of leakage. This was confirmed by SEM photographs which showed the adaptation of AH Plus sealer to the root canal wall under all magnifications when used with the lateral condensation technique. Previous studies showed that the dentin-sealer gaps with bio-ceramic sealers are smaller than those with epoxy resin-based sealers. Properties such as shrinkage resistance, insolubility in the oral fluids, and hydrophilicity can help in gap formation reduction with bio-ceramic sealers. Attributable to the features and composition of bio-ceramic sealers, they can also produce Ca\({}^{2+}\) hydroxide and hydroxyapatite, which can ensure an excellent bond to both the dentinal walls and the obturating core material [41; 42]. Therefore, voids act as a reservoir for the bacteria and microorganisms, resulting in microleakage and jeopardizing the long-term success rate of root canal treatment. CeraSeal is a premixed Ca\({}^{2+}\) silicate-based sealer. According to the manufacturer, this sealer consists of Ca\({}^{2+}\) silicates, zirconium oxide, and thickening agent and has a superior antimicrobial effect and high volumetric stability. It is claimed that it can be used with single-cone obturation due to expansion and hermetic sealing [43]. Surprisingly, although CeraSeal is a Ca\({}^{2+}\) silicate-based bio-ceramic sealer, in the present study, 80% of the samples leaked over a period of 60 days. However, although this group had the most leaked samples, we must keep in mind that only two samples leaked within the first 7 days. This result may be due to the washout effect of the sealer. The washout effect is a phenomenon in which the resistance to the outflow decreases with the volume flowing through it [44]. This was confirmed by SEM photographs, which showed the least adaptation of CeraSeal sealer to the root canal wall under all magnifications when used with the single-cone technique. Portland cement is the major component of MTA. It is used as a binder in concrete. Ca\({}^{2+}\) silicate-based cements (the main component of the Portland cement in MTA) exhibit an increase in washout resistance after adding carboxymethyl chitosan or gelatin to their components [40]. The manufacturer added a thickening agent to the CeraSeal sealer to improve the washout effect of the sealer.