## 2 Nanomaterials in Endodontics
### Bioglass
Four weeks after application of the preparation, a thin dentin bridge was formed and no local inflammation or only minor inflammation was observed in the vicinity of the biomaterial [95]. Research indicates that the ions released by bioglass particles not only do not inhibit the growth of human dental pulp stem cells, but also contribute to the formation of a dense and strong dentin bridge. This discovery is important in the context of regenerative dentistry, where the formation of durable and strong dentin structures is crucial to maintaining tooth health and function [96; 97; 98]. The use of Bio-Gutta, i.e., gutta-percha in combination with Bioglass 4555, as an alternative to conventional gutta-percha in root canal treatment seems to be very beneficial. The combination of these two materials ensures the effective sealing of the root canals, which is crucial in preventing bacteria from leaking into the pulp cavity [99]. Additionally, Bio-Gutta has additional benefits, such as the ability to bond to the dentin walls without the need to use additional sealants, which improves the durability of the filling and simplifies the root canal treatment process [100; 101]. Additionally, the fact that Bio-Gutta is a biocompatible material means it has the potential to minimize allergic reactions or other unwanted side effects in patients [102]. Sealing the root canal system with biocompatible and dimensionally stable filling materials plays a key role in the success of endodontic treatment. Correct sealing can be achieved through the appropriate technique and use of the appropriate filling material, which must meet certain physicochemical and biological properties, such as flowability, viscosity and a good adhesion to the substrate [103]. Gutta-percha and endodontic cements are considered necessary materials in the final phase of endodontic treatment, enabling the filling of the root canal system [104]. However, one of the biggest problems associated with the failure of these procedures remains the lack of an apical seal, which may lead to the leakage of fluids from the oral cavity into the root canals, which in turn is associated with the recurrence of infection or other complications [105]. Therefore, bioactive glass is now added to endodontic sealants. In in vitro tests, samples of material with the addition of bioglass were hardened in a simulated body fluid and a gradual decrease in its pH was observed, which stabilized at a level of approximately pH = 10. It was shown that this pH value is optimal for the formation of hydroxyapatite on the surface of bioglass [106]. Bioglass is often supplemented with additional substances that support the fight against microorganisms. Thanks to the alkaline reaction of the material and the addition of silver, preparations with antibacterial properties are obtained. They prove to be effective in combating bacteria found in the oral cavity, such as _E. coli, P. aeruginosa, S. sanguinis, A. viscosus and S. mutans,_ responsible for the development of caries and periodontal diseases [107; 108; 109; 110]. An interesting example here is the research of [PERSON] et al., who created and then tested three different bioactive glass compositions produced using the sol-gel method [112]. These compositions differed in chemical composition and percentage of SiO\({}_{2}\), CaO, MgO and CuO. The researchers showed that two out of three bioglass nanoparticle compositions inhibit the growth of _E. faecalis_ after 48 h of incubation, while for all compositions a significant reduction in the viability of _C. albicans_ was noted [112]. An important requirement for materials sealing root canals is their biocompatibility, due to their direct contact with the hard tissues of the tooth and the soft tissues of the periapical area. In most studies, the biocompatibility of materials is assessed based on cytological tests [113]. This was also analyzed in in vivo studies after removal surgery of coronal and root pulp in rat teeth.