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The proposed study investigates the antimicrobial efficacy of eugenol, a bioactive compound derived from clove (Syzygium aromaticum), against Prevotella intermedia, a key pathogen implicated in periodontal diseases. Eugenol was extracted and evaluated at concentrations of 0.5, 1.0, and 2.0 mg/mL. Its antimicrobial performance was benchmarked against a standard 0.12% chlorhexidine mouthwash and a commercially available herbal formulation. Experimental analyses included biofilm inhibition assays, determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), and cytotoxicity assessment using human gingival fibroblasts (HGFs). The results demonstrate that eugenol exhibits a concentration-dependent antimicrobial effect, achieving comparable efficacy to chlorhexidine at the highest tested concentration. Moreover, eugenol significantly reduced biofilm formation while maintaining acceptable cytocompatibility. These findings highlight the potential of eugenol as a promising natural alternative for the prevention and management of periodontal diseases and support its incorporation into oral healthcare formulations.