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Journal of Isfahan Medical School

Journal of Isfahan Medical School

Comparative In Vitro Antimicrobial Activity of Mentha longifolia Essential Oil and Chlorhexidine Against Streptococcus mutans and Candida albicans

Document Type : Original Article (s)

Authors
1 Assistant Professor, Department of Oral and Maxillofacial Medicine, School of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
2 Postgraduate Student, Department of Periodontics, School of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
3 Professor, Department of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
4 Assistant Professor, Department of Periodontics, School of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
5 Undergraduate Student, Department of Periodontics, School of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
Abstract
Background: Oral infections and dental caries are significant health concerns, especially in developing countries. Streptococcus mutans and Candida albicans play key roles in dental caries and oral fungal infections, while chlorhexidine may have side effects. Plant-derived compounds such as Mentha longifolia essential oil are therefore being explored as alternative or adjunctive therapies. This study compared the antimicrobial effects of Mentha longifolia essential oil and chlorhexidine.
Methods: In 2025, an in vitro study was conducted at the Bacteriology Laboratory of Ahvaz University of Medical Sciences on S. mutans PTCC1683 and C. albicans PTCC10231 obtained from Iranian bacterial and fungal collections. Minimum inhibitory concentration (MIC), minimum bactericidal/fungicidal concentration (MBC/MFC), and microbial killing times were determined for both agents.
Findings: For S. mutans, MIC values were 0.035 µg/mL for chlorhexidine and 108.33 µg/mL for Mentha longifolia oil, with MBCs of 0.03 and 223.33 µg/mL, respectively. Both agents completely eradicated bacteria within 5 hours. For C. albicans, MICs were 0.56 µg/mL (chlorhexidine) and 7290.66 µg/mL (Mentha longifolia oil), with MFCs of 2.27 and 14583.33 µg/mL, respectively; Mentha longifolia oil eliminated the fungus within 1 hour, while chlorhexidine required 24 hours.
Conclusion: Chlorhexidine exhibited stronger inhibitory and bactericidal/fungicidal effects at lower concentrations. Nonetheless, Mentha longifolia essential oil demonstrated significant antimicrobial activity and may serve as a complementary option in future studies.

Highlights

Maryam Robati:Google Scholar ,PubMed

Keywords
Subjects

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Volume 44, Issue 872
4th Week, September
September and October 2026
Pages 1367-1374

  • Receive Date 28 July 2026
  • Accept Date 02 August 2026