Dental caries, one of the most common diseases worldwide, progresses over time if not treated in the early stages, leading to conditions that require more complex treatments [1]. During the treatment of advanced carious lesions, situations such as proximity to the pulp tissue or pulpal perforations may arise [2]. In such cases, preserving the tooth's vitality is essential not only for its innervation and defense mechanisms but also for the nourishment and formation of dentin [3]. Pulpal exposures that occur during the treatment of vital teeth must be promptly sealed with a material that can induce the differentiation of human dental pulp stem cells into odontoblast-like cells, thereby stimulating hard tissue regeneration [4], [5]. However, the success of this treatment, also known as pulp capping, may be compromised due to factors such as the presence of bleeding in the exposed area, the effects of residual bacteria, the size of the exposure, and certain material-related weaknesses [6], [7].

An ideal pulp capping material (PCM) should not only be biocompatible but also set quickly, resist dissolution, and possess antibacterial and remineralizing effects [8], [9]. The antibacterial properties of PCMs help eliminate residual bacteria and prevent new bacterial growth, thereby reducing the risk of further infection [10]. The remineralizing effect of the capping material is crucial for accelerating the formation of a new dentin bridge in the damaged area and strengthening the dentin structure [11]. Additionally, the presence of abundant minerals such as calcium and phosphate in the material and their gradual release over time can contribute to forming a more compact dentin bridge, potentially reducing post-procedural hypersensitivity. Furthermore, the release of calcium and hydroxyl ions supports pulp tissue healing and mineralized tissue formation, while alkalinity contributes to microbial elimination [12], [13].

For a material to serve as a scaffold for tertiary dentin formation in the area of pulpal exposure, it must be mechanically durable and resistant to dissolution in tissue fluids. Ensuring a tight seal in the exposed area enhances the success of pulp capping treatment; therefore, the capping material should have the ability to bond both to dentin and the restorative material placed over it. A PCM that lacks adhesion to dentin may allow tissue fluid infiltration into the restoration area during treatment, facilitating the passage of residual bacteria in the cavity toward the pulp [11].

Currently, materials containing calcium hydroxide, calcium silicate, or resin-reinforced calcium silicate are used in vital pulp therapies [11], [14]. Calcium hydroxide-based materials have several disadvantages, including weak adhesion to dentin, high solubility, the formation of porous dentin bridges, and poor mechanical stability [14]. Mineral Trioxide Aggregate (MTA), a tricalcium silicate-based material, is considered the gold standard today. While MTA exhibits excellent antimicrobial properties and biocompatibility, it has drawbacks such as a long setting time, handling difficulties, extended preparation time, high cost, potential tooth discoloration, and weak bonding to resin-based materials [15], [16], [17]. Biodentine, a widely used alternative to MTA, exhibits reduced setting and handling times; however, these durations remain relatively prolonged (12 min for Biodentin), which may still pose clinical limitations [17]. To overcome these limitations, light-curable, resin-based calcium silicate PCMs have been developed [4]. However, resin-reinforced calcium silicate materials still have limitations, such as low calcium ion release, weak remineralization potential, and limited antibacterial effects [18]. Therefore, the search for an ideal PCM that optimally combines all the desired properties continues.

Calcium fructoborate (CF) is a plant-based sugar borate ester that simultaneously contains calcium and boron elements [19]. Extensive in vitro scientific research on CF has reported that it exhibits biological activities with potential therapeutic effects, including anti-inflammatory, anti-osteoporotic, antioxidant, and antitumor properties [20], [21], [22]. Compared to other commercial boron forms, this form of boron is considered safer and biologically available [20]. Research on the antibacterial activity of boron-containing compounds has shown that these compounds have the potential to prevent bacterial infections, especially [23].

Mesoporous silica material was discovered by researchers in the 1990s and quickly found applications in a wide range of fields [24]. Among the most commonly used types of mesoporous silica are MCM-41, MCM-48, KIT-6, and SBA-15 [25]. These nanoparticles have significant potential, particularly in catalyst transportation, drug delivery, sensor technology, and biological imaging. Among these materials, SBA-15, a mesoporous silica with an ordered hexagonal structure, has been one of the most extensively studied. SBA-15 is synthesized in a strongly acidic environment using block copolymer surfactants and is notable for its pore sizes ranging from 3 to 30 nm [26]. It is frequently preferred for incorporating biological agents into silica structures and studying the release kinetics of these agents from the matrix [27], [28].

In the literature, no study investigates the addition of CF into PCM formulations, either with or without a carrier. Therefore, this study aims to develop an experimental PCM by incorporating CF-loaded SBA-15 into a conventional resin-based PCM, aiming to create a formulation that supports cell attachment, allows hard tissue formation, exhibits antibacterial properties, is biocompatible, and has mechanical durability. The null hypotheses tested in this study are as follows:1.

The addition of CF-loaded SBA-15 reduces water absorption without significantly affecting the solubility of the resin-based PCM.

2.

The addition of CF-loaded SBA-15 has no effect on the monomer conversion degree of the resin-based PCM

3.

The addition of CF-loaded SBA-15 improves the antibacterial efficacy of the resin-based PCM.

4.

The addition of CF-loaded SBA-15 enhances the biocompatibility of the resin-based PCM.

5.

The addition of CF-loaded SBA-15 increases the hard tissue formation potential of the resin-based PCM.