Introduction. Secondary caries is the most important reason for replacement and removal of restorative materials containing composite resins, because caries causes infectious complications and many bacteria, including Streptococcus mutans and lactobacilli, which have been isolated from cariogenic plaques, once known that composites based on resins favour the growth of Streptococcus. Therefore, the use of composite resins with antimicrobial properties for the prevention of secondary decay will be very useful; to this end, we synthesized 4-amino-2H-chromen-2-one as a new antibacterial compound, used it in dental composites, and investigated its physical-mechanical properties. Materials and methods. In this experimental study, 4-amino-2H-chromen-2-one was synthesized by the reaction between 4-hydroxy coumarin and ammonium acetate and the antibacterial activity of flowable dental composites containing 0–5 wt% 4-amino-2H-chromen-2-one, as well as their mechanical and physical properties, influencing flowable dental composites, were investigated. Statistical analysis was performed using one‑way ANOVA test (P < 0.001). Results and discussion. The direct contact test demonstrates that, by increasing the 4-amino-2H-chromen-2-one content, bacterial growth is significantly diminished (p<0.001). Average flexural strength results show that, with increasing 4-amino-2H-chromen-2-one until 2% in the composite, no significant difference was observed in flexural strength (p>0.001), while the mean of compressive strength results shows no significant difference between 0-4% groups (p>0.001). Conclusions. Incorporation of 4-amino-2H-chromen-2-one into flowable resin composites in 2% wt can reduce the activity of Streptococcus mutans.
Keywords:- antibacterial
- dental composites
- mechanical properties
- resin composites