Chairs: Ed Deshmukh-Reeves and Rebecca McHugh

Biofilms are central to development of oral diseases, particularly dental caries, which exhibit heightened resistance to conventional treatments such as chlorhexidine. This study investigated antibiofilm properties of Omega-3 (n-3) fatty acids Eicosapentaenoic acid (EPA, C20:5) and Docosahexaenoic acid (DHA, C22:6) against Streptococcus mutans ATCC 25175, a primary cariogenic pathogen. Using a modified McBain medium simulating salivary conditions, bacterial growth was assessed at concentrations 250, 100, 50, 25, and 10 µg/ml. Minimum biofilm inhibitory concentration (MBIC) was determined on titanium discs preconditioned with artificial saliva and assessed using colony enumeration, crystal violet staining, and scanning electron microscopy (SEM). Cytotoxicity and proliferation effects on TR146 oral cells were assessed using lactate dehydrogenase (LDH) release and XTT assays. Additionally, n-3 incorporated medical-grade shellac coatings were evaluated for biofilm prevention. EPA and DHA significantly inhibited S. mutans growth and biofilm formation at 250-100 µg/ml. EPA was most effective in the presence of artificial saliva, with 25 µg/ml effecting growth and biofilm formation when exposed to salivary components. DHA was less effective at the same concentration, suggesting that salivary components may buffer or diminish its antibiofilm activity. Lowest concentration 10 µg/ml displayed no significant antibiofilm activity however, exhibited limited cytotoxicity compared to chlorhexidine. Shellac coatings containing Omega-3s effectively reduced surface biofilms in a dose-dependent manner, with SEM confirming biofilm inhibition at higher concentrations. These findings highlight the potential of Omega-3 fatty acids, particularly EPA, as alternative antibiofilm agents against S. mutans, offering a promising approach for caries prevention with reduced cytotoxicity.