Silver Ions To Essential Lipids: A Comparative In-Vitro Analysis of the Antimicrobial Action of Silver Diamine Fluoride and Omega-3 Fatty Acids Against Streptococcus Mutans

AIM & BACKGROUND: Dental caries is a widespread global disease, with Streptococcus mutans playing a key role in its development. Silver diamine fluoride (SDF) is an effective antimicrobial and caries-arresting agent; however, its use is limited by tooth discoloration. Omega-3 fatty acids have shown antimicrobial potential with limited evidence in caries management, highlighting the need for safer and aesthetically acceptable alternatives. To compare the antimicrobial efficacy of silver diamine fluoride (SDF) and omega-3 fatty acid against Streptococcus mutans using an in-vitro model. METHODS: Streptococcus mutans was isolated from a carious lesion and cultured in tryptic soy broth. The bacterial suspension was standardized to 0.5 McFarland and diluted to 1 × 10⁵ CFU/mL. Test agents included 38% SDF and omega-3 oil emulsified with Tween-80 and ethanol. Serial two-fold dilutions were prepared, and bacterial inoculum was added to microtiter wells. Following incubation at 37°C for 24 hours, bacterial viability was assessed using the MTT assay, and optical density was measured at 540 nm. RESULTS: The growth control optical density (OD) was 0.436. Omega-3 fatty acid at 100 mg/mL (OD 0.104) demonstrated antimicrobial activity comparable to SDF at 25 mg/mL (OD 0.110). Similarly, 50 mg/mL omega-3 (OD 0.122) showed effects comparable to 12.5 mg/mL SDF (OD 0.126). Although both agents significantly reduced S. mutans growth, SDF exhibited superior antibacterial efficacy. CONCLUSION: SDF remains more effective against Streptococcus mutans; however, omega-3 fatty acid demonstrated notable antimicrobial potential without causing tooth discoloration. CLINICAL-SIGNIFICANCE: Omega-3 fatty acids may serve as a biocompatible adjunct or alternative in caries management, particularly where aesthetics is a concern. Further studies exploring synergistic combinations and clinical applications are warranted.