Development and Evaluation of Carvacrol‐Loaded Methacrylate Dental Composites with Antibacterial Activity

Abstract Secondary caries is a leading cause of failure in resin‐based restorations, emphasizing the need for materials with intrinsic antimicrobial activity. This study presents the systematic incorporation of carvacrol, a natural phenolic compound with proven antimicrobial properties, into methacrylate‐based dental composites. Experimental resins were prepared with 2%, 4%, and 6% carvacrol by weight and evaluated for polymerization kinetics, flexural strength, elastic modulus, water sorption, solubility, degree of conversion (DC), antimicrobial activity, and cytotoxicity. Results showed that the 6% carvacrol formulation reduced Streptococcus mutans viability by over 90%, while maintaining flexural strength above 80 MPa and a DC comparable to the control. Water sorption significantly decreased with increasing carvacrol concentration, attributed to its hydrophobic nature. However, higher concentrations also led to increased cytotoxicity in fibroblast cultures. These findings highlight the potential of carvacrol as a multifunctional additive to impart antibacterial functionality to dental resins, though concentration‐dependent trade‐offs with biocompatibility must be considered. To our knowledge, this is the first study to comprehensively evaluate carvacrol‐loaded methacrylate resin composites, offering a promising strategy to address secondary caries and enhance restoration longevity.