Antibacterial effect of a dental adhesive containing SCH-79797 on Streptococcus mutans biofilms

Antibacterial modification of dental adhesives has emerged as a viable strategy for caries prevention. In this study, a newly identified dual-target antimicrobial, SCH-79797, known for its strong antibiofilm activity, was incorporated into a dental adhesive. Its antibiofilm performance was subsequently evaluated using a Streptococcus mutans (S. mutans) biofilm model.

The bonding performance, polymerization behavior and surface wettability of the SCH-79797-modified adhesive were evaluated by shear bond strength testing, degree of conversion, and water contact angle measurements, respectively. Biocompatibility was examined in L929 fibroblasts using CCK-8 assays and live/dead cell staining. Antibacterial activity against biofilms was evaluated through CFU counting, MTT assays, SEM observation, and live/dead bacterial staining. In addition, biofilm virulence was evaluated by analyzing water-insoluble polysaccharide and extracellular polysaccharide (EPS) production, as well as changes in pH and lactic acid production.

Incorporating SCH-79797 at concentrations up to 0.5% did not adversely affect the adhesive properties and resulted in minimal cytotoxicity. Compared with the control, the SCH-79797-modified adhesive reduced bacterial viability by approximately 6 log CFU, and significantly decreased lactate production and EPS synthesis by approximately 90% and 90%, respectively.

These findings indicate that SCH-79797-modified dental adhesives possess promising in vitro anticaries activity against cariogenic bacteria.