# Antibacterialarial Agents Used in Modifications of Dental Resin Composites: A Systematic Review
## 4 Discussion
### Modification of RBC Compositions
#### 4.2.2 Other Additives  
[PERSON] et al. [38] proposed CuAAC-based composites made from different azide monomers and different copper concentrations. They formed biofilms from _Streptococcus mutans_ strains expressing luciferase. It was shown that the number of viable bacteria was reduced for biofilms grown on CuAAC-based composites compared to the control sample. No information about the strength and cytotoxicity of the modified materials was provided. [PERSON] et al. [39] proposed a composite prepared with amorphous calcium phosphate nanoparticles (NACPs) with or without dimethylaminohexadecyl methacrylate (DMAHDM). The study showed that the flexural strength and modulus of the experimental composite enriched with NACP-DMAHDM were similar to those of the control sample. The addition of DMHDM to the rechargeable NACP composite did not adversely affect the release and loading of Ca and P ions, and the composite showed significantly less biofilm growth [39]. These promising results in terms of remineralization and biostatic properties should be studied further to assess their lastingness and efficiency. [PERSON] et al. [40] also used DMAHDM or low-shrinkage-stress resin and NACP as potential composites with remineralizing and antimicrobial (against _Streptococcus mutans_) properties. As a control, a commercial composite (Heliomolar, Ivoclar) was used. The experimental monomers were found to have similar fibroblast viability to the commercial material used as a control. There was no negative effect of DMAHDM on the hydration of Ca and P ions. In addition, the flexural strength was similar to that of the control material, while the hardness of the control was twice as low as the values obtained for the experimental materials. Commercial bulk-fill materials containing antimicrobial fillers (alkasite), such as barium aluminosilicate glass and ytterbium trifluoride, were characterized by antibacterial properties, but these properties were weaker than those presented by chlorhexidine [41]. [PERSON] et al. [42] introduced a filler in the form of halloysite nanotubes loaded with chlorhexidine (HNT/CHXs; various mass fractions from 1 to 10% by weight). The experimental composite enriched with HNT/CHXs inhibited the growth of _Streptococcus mutans_. In addition, MTT tests showed that materials prepared with halloysite nanotubes loaded with chlorhexidine showed no cytotoxicity against NIH 3T3 fibroblast cells compared to the control sample. The results of the study may suggest a favorable safety profile, which in the long term may allow the material to be used clinically. Tests showed that the modification improved the elastic modulus, flexural strength, and compressive strength of the tested material [42]. The improvement in these properties is very promising, but it is important to evaluate the long-lasting durability and strength of the material. Core-shell chlorhexidine/amorphous calcium phosphate (CHX/ACP) nanoparticles were also successfully used to modify the resin composite. The best compromise between antimicrobial and mechanical properties was presented by the material prepared with 5 wt% CHX/ACPs [43]. Since this composite releases some ions, further studies on changes in its properties should be planned. [PERSON] et al. [44] used an inorganic antiseptic, magnesium oxide (nMgO), and a remineralizing agent, bioactive glass (BAG), to modify a composite resin. During the study, it was shown that the simultaneous introduction of nMgO and BAG into the composite material achieved very good antimicrobial properties against _Streptococcus mutans_, while the presence of BAG resulted in improved remineralization capacity with increasing substance concentration. The modification did not significantly affect hardness, flexural, or compressive strength, but the water sorption and curing depth increased with increasing amounts of nMgO and BAG. Increased water sorption can cause premature material degradation, affecting material performance. Further research is needed regarding the stability of the experimental composite.