For decades, it has played a significant role in dental materials and pharmacology due to its broad biological activities, which include analgesic, anti-inflammatory, antimicrobial, antioxidant, and sedative effects.
Pharmacological Properties Relevant to Dentistry
1. Analgesic and Sedative Effects
★ Eugenol acts on peripheral nociceptors, reducing pain perception.
★ It has a local anesthetic-like effect by blocking voltage-gated sodium channels in sensory nerves.
★ This explains its widespread use in temporary restorative materials for pulpal sedation and pain relief.
2. Anti-inflammatory Activity
★ Inhibits prostaglandin synthesis by blocking cyclooxygenase (COX) enzymes.
★ Reduces inflammatory mediators (e.g., TNF-α, IL-1β), which contributes to pain control in cases of pulpitis and post-extraction inflammation.
3. Antimicrobial Properties
★ Exhibits broad-spectrum antimicrobial action against oral pathogens such as Streptococcus mutans, Enterococcus faecalis, and Candida albicans.
★ Useful as an adjunct in endodontic disinfection and dry socket management (alveolar osteitis).
4. Antioxidant Action
★ Scavenges free radicals, reducing oxidative stress in inflamed dental tissues.
★ This property may help protect periapical and pulpal tissues during healing.
► DENTAL MATERIALS: Clinical Applications for Dental Assistants and Dental Hygienists - W. Stephan Eakle and Kimberly G. Bastin (2025)
Clinical Applications in Dentistry
1. Restorative Dentistry
★ Used in zinc oxide–eugenol (ZOE) cements as a base, liner, or temporary restorative material.
★ Provides pulpal sedation in deep cavities.
★ Serves as a sealer for temporary and sometimes permanent restorations.
2. Endodontics
★ Incorporated into root canal sealers.
★ Applied in the management of symptomatic pulpitis.
★ Occasionally used as an intracanal medicament due to its antimicrobial activity.
3. Oral Surgery
★ Key ingredient in dressings for alveolar osteitis (dry socket), helping relieve pain and promote healing.
4. Periodontics
★ Included in some periodontal dressings as an antiseptic and anti-inflammatory component.
Limitations and Safety Considerations
★ Cytotoxicity: In high concentrations, eugenol can cause irritation and necrosis of the pulp or soft tissues.
★ Allergic Reactions: Some patients may develop contact dermatitis or hypersensitivity.
★ Incompatibility: Eugenol can inhibit the polymerization of resin composites; therefore, its use under composite restorations is not recommended.
Conclusion
Eugenol remains a fundamental therapeutic agent in dentistry. Its unique combination of analgesic, anti-inflammatory, and antimicrobial effects ensures its continued role in restorative dentistry, endodontics, oral surgery, and periodontics.
Despite the rise of synthetic alternatives, eugenol-based materials are still preferred worldwide due to their effectiveness, affordability, and long clinical history.
For best outcomes, clinicians should use eugenol-based materials judiciously, considering both their benefits and potential adverse effects, especially when working near vital pulp tissues or planning composite restorations.
