In vitro evaluation of the antimicrobial efficacy, antibiofilm effect, and resistance to biodegradation of a novel composite against Streptococcus mutans.

Background and Aim: Research confirming the ability of cariogenic bacteria Streptococcus mutans to degrade dental resin composites and adhesives is of great concern as it points a finger on the clinical longevity of the restoration. Incorporation of antibacterial particles to the composite may serve as a potent solution to overcome this detrimental effect. This study evaluated the antimicrobial efficacy, antibiofilm effect, and resistance to biodegradation of a novel composite and commercial composite incorporated with zinc oxide nanoparticles (ZnO-NPs) against S. mutans. Materials and Methodology: Thirty six samples (12 samples each) of Group I (Tetric N Ceram), Group II (Novel composite, Sri Chitra Tirunal Institute for Medical Sciences and Technology [SCTIMST]), and Group III (Tetric N Ceram incorporated with 5 wt% ZnO-NPs) were prepared for the study. Antibacterial efficacy was measured using direct contact test, antibiofilm effect was tested on 7-day-old biofilm using live-dead staining and viewed under confocal Raman microscope, and resistance to biodegradation was measured using high performance liquid chromatography, all tested against S. mutans. Results: Intergroup evaluation of antimicrobial efficacy, antibiofilm effect, and resistance to biodegradation showed that Group II and Group III showed significantly favorable results as compared to Group I, tested using analysis of variance followed by post hoc analysis. Conclusion: The novel composite (SCTIMST) and composite incorporated with 5 wt% ZnO-NPs have better antibacterial property, antibiofilm effect, and resistance to biodegradation as compared to the unmodified composite, against S. mutans.