## 1 Introduction  
The key objective of root canal treatment is to eradicate microorganisms within the root canal system and establish a barrier that ensures effective sealing of the canal. This is essential to prevent bacterial recontamination of the surrounding structures, including the oral cavity (and its microbiome) and periapical tissues [1; 2; 3]. After adequate chemical-mechanical preparation, the three-dimensional root filling hermetically seals the root canal system, preventing both bacterial colonization and the infiltration of oral cavity fluids into periapical tissues and thus establishing suitable conditions for periradicular tissue healing [4; 5; 6; 7]. In situations involving pulp necrosis in teeth with compromised root formation, the therapeutic approach poses a clinical challenge, as difficulties may appear in different steps of the treatment, particularly in establishing the boundaries of instrumentation, disinfection and root canal filling [8; 9]. Following deep caries lesions, developmental anomaly or trauma, an immature tooth may undergo compromised root maturation, with the absence of root apex closure and the interruption of root formation before reaching the final length [8; 10]. The interruption of the root formation leads to a divergent apical configuration, rendering it challenging to attain precise control of the working length for the root filling material [9]. This configuration, coupled with the absence of apical constriction, may result in the extrusion of intracanal dressing, irrigating solutions and the obturation material into the periapical tissues, which can lead to the failure of the root canal treatment [8; 11]. Current treatment techniques for necrotic teeth with open apex include apexification, the placement of an apical plug and regenerative endodontic treatment [12]. Apexification is an endodontic procedure that promotes the formation of a biological barrier or apical plug into the apical portion of the root. This process facilitates the closure of the root canal, establishes a boundary for the root filling material and prevents overfilling into the periapical tissues [13]. In contrast to regenerative endodontic treatments, apexification typically lacks the capacity to promote the thickening of dentin walls or to provide the root development of the tooth [13]. An apical plug is an alternative to the previously mentioned technique [8; 14; 15]. Plugs with an extension of 3-5 mm are deemed appropriate for optimizing marginal adaptation and achieving efficient sealing, thus enhancing therapeutic success [11; 16]. The materials employed in this clinical procedure should possess the ability to consistently provide sealing, exhibit good biocompatibility, ensure effective adhesion to root canal walls and maintain dimensional stability. Additionally, it is imperative for these materials to be hydrophilic [17; 18], with a low solubility, be easy to handle and have a short setting time and good radiopacity [19; 20]. Over time, innovative endodontic cements based on calcium silicates have been developed, including mineral trioxide aggregate (MTA) and other hydraulic calcium silicate cements [21]. MTA is a biomaterial resulting from a mixture of Portland cement and bismuth oxide, with smaller amounts of SiO\({}_{2}\), CaO, MgO, K\({}_{2}\)SO\({}_{4}\) and Na\({}_{2}\)SO\({}_{4}\)[16]. Upon contact with periapical tissue, MTA can stimulate the formation of hydroxyapatite-like hard tissue [22], showing its ability to induce odontoblastic differentiation [23]. In addition to these benefits, MTA also demonstrates a low solubility, good radiopacity, antimicrobial activity, high pH and expansion after setting [24]. However, the extended setting time, handling challenges and the potential of coronal discoloration associated with MTA have prompted the investigation of new materials to overcome these issues [25; 26]. Lately, new hydraulic calcium silicate cements have been introduced in endodontics as alternatives to MTA [11].