## 4 Discussion
It has been demonstrated that hexagonal boron nitrate (h-BN) can inhibit bacterial growth in a cell culture medium [28], and the incorporation of sodium pentaborate pentahydrate into the structure of dental composites at specific ratios has been proven to significantly suppress bacterial growth according to direct contact test results [3]. Additionally, the addition of boron nitride nanotubes with fissure sealant has been found to reduce the surface energy of the composite structure and enhance the bioactivity of the fissure sealant [16]. When the literature is thoroughly examined, the presence of a limited number of studies is evident, and in existing studies, it is often observed that one or two types of boron materials are usedand added to the structure in different percentages. The majority of these studies focus on antibacterial activity, whether or not there is therapeutic efficacy. At this crucial point, what becomes important is the size of the impact of the added boron material on the mechanical properties of the composite structure. One of the most crucial factors for a restoration to endure within the oral cavity for an extended period of time is its ability to withstand chewing forces. It is an undeniable fact that there are already numerous therapeutic agents available for use when performing a restoration in the oral cavity. In studies related to boron, it is essential to first examine to what extent the mechanical properties are affected if added to the composite structure. Then, work with numerous boron materials, and organize subsequent studies by selecting the most suitable boron materials. After obtaining the data, the antibacterial efficacy or cytotoxic effect of the relevant boron material should be evaluated. Based on this, this study was designed to work with numerous boron materials, with all materials added to the structure in equal proportions. In this study, a microhybrid-type composite material was used as the base, and the same composite was used in all experimental groups. Currently, there is no in vitro evidence in the literature suggesting that nanofill or submicron resin composites exhibit better smoothness or gloss compared to traditional microhybrids [29]. Of course, it is an undeniable fact that nanofil or nanohybrid-based dental composites can demonstrate clinical performance, marginal adaptation, and mechanical properties similar to traditional composites. However, according to the conducted study, it has been revealed that nearly three-quarters of dentists preferentially choose a microhybrid composite material for direct restorations [30]. In this context, it was decided to incorporate a microhybrid-based composite in our study. Additionally, in such studies, boron derivatives can be introduced using different methods [3; 9; 17]. The sol-gel method facilitates the formation of nano-sized filler particles and provides a higher content of nanofillers compared to traditional microfilled composites [31]. At the same time, boron materials can be incorporated into the polymer chain by hydroborating organic double bonds through the corroboration method. This method can reveal polymerization efficiency and yield controllable polymer structures [32]. Instead of these methods, the technique employed in the study by [PERSON] et al. [3] was applied due to financial reasons and laboratory facilities. This situation constitutes one of the limitations of the study. Surface microhardness tests are a testing methodology that is widely utilized not only in industrial settings but also in the dental field, offering crucial insights into the durability, performance, and quality of materials. These tests ensure control over materials and manufactured components by measuring a material's resistance to scratching. According to conducted research, various tests such as Brinell, Rockwell, Vickers, Knoop, Barcol, and Shore are commonly employed to determine the hardness of dental materials [33; 34].