# The Impact of Silver Nanoparticles on Detntinal Tubule Penetration of Endodontic Bioceramic Sealer
## 4 Discussion
Confocal microscopy was employed in the current study to assess sealer penetration, as it enables the precise detection of sealer penetration along the canal circumference by establishing different contrast points within the dental tubules. This method allows for the exclusion of artifacts and backgrounds to improve image analysis, while also allows for detection control at differing depths of the sample [37]. Additionally, the labeling dye (Rhodamine B) employed in this study has been demonstrated to exhibit robust fluorescence within dental tubules and does not affect the physical properties of the sealer [38]. The TotalFill(r) Hillow BC sealer was used in the current investigation due to many reports indicating a high flow rate that allows for good penetration ability. [PERSON] et al. reported that the TotalFill(r) BC sealer attained the maximum flow rate of 30.8 mm in comparison to other bioceramic sealers [15]. [PERSON] et al. also reported a high flow rate of 24.83 mm for the TotalFill(r) BC sealer compared to other BC sealers [12]. Earlier research has shown that the incorporation of nanoparticles into endodontic sealers enhances the flow by lowering their viscosity. While the mechanical or physical characteristics of the modified sealer remained unchanged [39]. Our findings are consistent with previous data, indicating that the BC sealer with AgNPs had greater penetration distance (1417-2096 \(\upmu\)m) relative to groups devoid of AgNPs. Consequently, the degree of tubular penetration and adaptation is influenced by the type of sealer used. The impact of different obturation techniques on the tubular penetration depth of the sealers employed was assessed in numerous studies. When utilizing a variety of BC sealers, such as EndoSequence(r) BC Sealer HiFlow, EndoSequence(r) BC Sealer, Bio-C(r) Sealer, MTA Fillapex, and TotalFill(r) BC Sealer, the warm vertical technique achieved a higher level of tubular penetration than the single-cone technique [14; 30]. This was in direct opposition to our conclusions. Nevertheless, a prior investigation did not identify any substantial distinctions between the obturation techniques (continuous condensation wave and single-cone) when using BC sealer [14]. Additionally, numerous investigations determined that the sealer penetration was not affected by the obturation technique [26; 29]. Our findings supported the recommendation to use BC sealers with cold obturation techniques, particularly the single-cone technique. The continuous condensation wave technique's heat generation could potentially alter or weaken the physical properties of the sealers, leading to a weaker bond, a shorter setting time, and a slower flow rate [40]. Therefore, the manufacturer's instructions recommend using the Hillow form of the BC sealer, with warm obtution techniques up to 220 \({}^{\circ}\)C. The HiFlow premixed BC sealers are made up of zirconium oxide, tricalcium silicate, dicalcium hydroxide, and fillers. Heat did not adversely affect the physical properties of these sealers, including the setting time, microhardness, solubility, chemical composition, and cytotoxicity [41]. Under high temperatures, HiFlow BC sealers had superior performance on flow, viscosity, and film thickness compared to conventional BC sealers. Furthermore, using the continuous wave obturation technique with the Hillow BC Sealer resulted in a greater intratubular penetration compared to single-cone techniques [42]. Multiple prior studies examined different regions of the root to evaluate the penetration depth of calcium silicate-based sealers; it was observed that the penetration depth decreased as we moved toward the apical third [43; 44].