# The Impact of Silver Nanoparticles on Detntinal Tubule Penetration of Endodontic Bioceramic Sealer  
[PERSON]  
1 Division of Endodontics, Department of Restorative Dental Science, College of Dentistry, King Saud University, Riyadh 13313, Saudi Arabia; [EMAIL_ADDRESS]  
2 University Dental Hospital, King Saud University, Riyadh 13313, Saudi Arabia;  
[EMAIL_ADDRESS]  
3 [EMAIL_ADDRESS]  
4  
[PERSON]  
5 Department of Electrical and Engineering Sciences, University of Utah, Salt Lake City, Utah, Salt Lake City  
sealers enhances and extends their antibacterial efficacy, while limiting the potential for bacterial resistance. This effectively eliminates residual bacteria in the root canal and inhibits their proliferation [4; 5]. The addition of AgNPs to sealers will impact their characteristics, including setting time, stiffness, solubility, and biochemical affinity to dentin. Furthermore, it will enhance the depth of penetration of zinc oxide sealer into the dentinal tubules [6]. Endodontic sealers, including zinc oxide-based, epoxy resin-based, and bioceramic (BC) sealers, are primarily employed to fill the gap between the core filling material and the root canal walls, ensuring a hermetic seal. Bioceramic sealers, in particular, differ from other sealer types due to their unique composition and properties. These sealers are made of ceramic materials predominantly composed of alumina, zirconia, bioactive glass, calcium phosphate, and hydroxyapatite [7; 8]. Notably, BC sealers exhibit strong bonding capabilities with dentin, attributed to their calcium phosphate content. This chemical similarity to the composition of natural tooth and bone material facilitates enhanced adhesion [9]. BC sealers have become increasingly popular in recent years due to their outstanding biocompatibility, ability to stimulate bone growth, antimicrobial properties, high radiopacity, and exceptional sealing capabilities [10]. The sealing effectiveness is enhanced by the sealer's penetration into the dentinal tubules creating a mechanical interlock [11]. The degree of tubular penetration varies depending on the physical and chemical properties of different sealers [12]. Moreover, the depth to which a sealer can penetrate dental tubules is determined by the irrigation protocol and the method of irrigation activation [13; 14]. BC sealers demonstrate a high flow rate and enhanced penetration depth into dental tubules [15]. Yet, there are contradictory results concerning the ability of the BC sealer to penetrate dental tubules. Some investigators discovered that there was no significant difference in the penetration of dentinal tubules when comparing epoxy resin and BC sealers [16; 17]. However, other studies reported improved penetration of dentinal tubules when utilizing BC sealers [18; 19]. Previous studies have indicated that the obturation technique, such as the single-cone (SC) or continuous wave condensation (CWC), may influence the sealer's penetration into dentin, with the CWC generally resulting in deeper sealer penetration than the SC [10; 20]. The SC technique involves placing a pre-fitted gutta-percha (GP) cone, coated with sealer, into the root canal at the working length (WL). A heated instrument is then used to trim the cone at the canal orifice. In contrast, the CWC technique begins similarly, with a GP cone coated in sealer that is then introduced to the WL. However, after initial placement, a heated instrument is advanced into the canal to a depth approximately 5 mm short of the WL for the pack down phase. Vertical condensation is then applied using endodontic pluggers, and the canal is subsequently backfilled with thermoplasticized GP [21; 22]. Incorporating AgNPs into BC sealers will enhance their antibacterial efficacy, raise the pH level, decrease solubility, and accelerate the setting times [5; 23]. However, the impact of adding AgNP to BC sealers on their ability to penetrate dental tubules is still unknown.