Screening and Efficacy Assessment of Deep Eutectic Solvents for Potential Application in Dental Cleaning

Background: Effective removal of tenacious calculus and extrinsic stains without oral irritation remains a major challenge in dental cleaning. Deep eutectic solvents (DESs) are tunable green solvents, but their potential for dental care is largely unstudied. This study screened DESs assembled from food-grade starting components and evaluated their cleaning efficacy, antibacterial activity and preliminary biosafety. Methods: Twelve DESs were synthesized and characterized. Their solubilization toward dental stain-related components was tested under stirring, ultrasonication and electro-stirring. The best-performing DESs were further assessed on natural dental calculus and stained bovine teeth, with comparison against commercial dental cleaners. Antibacterial effects and biosafety were also determined. Results: Hydrophilic low-pH DES-3 (maleic acid-xylitol) and DES-5 (lactic acid-citric acid-xylitol) efficiently dissolved calcium phosphate and pigments, while hydrophobic DES-12-P emulsion performed best for oily stains. Cleaning performance depended on DES concentration and agitation approaches. The optimized DES outperformed commercial products for complex mixed stains on bovine teeth with no enamel damage. It also displayed potent antibacterial effects against Staphylococcus aureus and Escherichia coli, with good biosafety in zebrafish tests. Conclusions: DESs exhibit favorable cleaning and antibacterial performance under the tested in vitro conditions, suggesting their potential as a candidate strategy for dental hygiene and oral care applications.