applied sciences  
The Impact of Incorporating Five Different Boron Materials into a Dental Composite on Its Mechanical Properties  
[PERSON] and [PERSON],*(c)  
Boron exists within the human body, with the greatest amount found in bones and teeth [6]. However, increasing the intake of boron changes the mineral composition of the teeth and shows beneficial effects on the alveolar bone in moderate amounts [7]. Boric acid can reduce alveolar bone loss [8]. Boron enhances the odontogenic and osteogenic differentiation processes in human dental germ stem cells, promoting the proliferation of human dental pulp stem cells. Moreover, it exerts a substantial influence on the growth and development of both bones and teeth [9]. AN0128 is a compound containing boron and possesses antibacterial and anti-inflammatory characteristics. A study conducted to test its potential effectiveness in the treatment of periodontal disease in rats shows that when experimental periodontitis is created by placing ligatures, histological and micro-CT evaluations significantly reduce the occurrence of inflammatory leakage and reduce bone density [10]. The addition of boron to silicate bioactive glass has recently emerged as an effective way to strengthen the mechanical properties thanks to the ability to form a boron network in the glass structure. Bioactive glass containing boron has shown improved biocompatibility and a certain antibacterial activity [9]. In studies with different materials, boron provides. For example, the addition of a small amount of boron significantly improves the casting structure and strength of titanium alloys [11].  
Today, the most commonly utilized and preferred material for restorative treatments in dentistry is resin-based dental composite materials. Since the introduction of resin-based composites in dentistry, many strategies have been tested to obtain a new material with superior physical and chemical properties, such as mechanical and antibacterial properties [12]. Boron-doped bioactive glass nanoparticles (BG-NPS) are used on dental pulp stem cells and are also used in dental tissue engineering as a coating material for dental implants [13]. Methacrylate-based adhesive resin containing boron nitride nanotubes (BNNTs) can be successfully incorporated as a filler [14].  
In addition to including some metal oxides such as titanium, silver, and zinc oxides to increase the antibacterial activity of the composite on secondary caries, which are the causes of failure in composite fillings [3], boron nitride nanolayers and their zinc oxide-modified derivatives have also achieved good mechanical properties [12]. In a study related to adhesives, it was also concluded that boron nitride nanotubes were successfully incorporated into a resin-containing adhesive, which is beneficial for their improved physicochemical properties and long-term bond stability without reducing the viability of fibroblast cell growth [15]. In the context of preceding studies, this investigation was orchestrated to examine the impact of incorporated boron material on dental composites, with a specific focus on elucidating which type of boron would prove more efficacious, particularly concerning various mechanical properties such as surface roughness, surface microhardness, and color stability. The hypothesis of the study is that in all experimental groups with added boron, surface roughness, upper surface microhardness, and color stability values will yield better results compared to the control group.