From Plant-Derived Compound to Bioactive Agent in Dentistry: The Expanding Role of Thymol

Background: Thymol has been considered a possible bioactive phytocompound in dentistry due to its antimicrobial, antibiofilm, antifungal and anti-inflammatory properties. The current narrative review aims to critically review the present evidence on biological properties, mechanism of action, formulations and applications of thymol in preventive dentistry, periodontics, endodontics, prosthodontics and emerging dental materials and delivery systems, highlighting the current limitations and future perspectives. Methods: A literature search was carried out on PubMed, Scopus, ScienceDirect and Google Scholar databases. The search included publications related to thymol and its applications in oral health and dentistry. Results: The most recent evidence supports the adjunctive use of thymol in preventive and periodontal oral-care products, particularly in essential oil-based formulations. Moreover, recent advances in nanoformulations and dental materials suggest that its therapeutic potential can be further improved by optimized delivery systems. Conclusions: Thymol is a naturally occurring active compound that offers numerous benefits in various dental applications due to its multifaceted properties and safety profile. Preliminary and clinical evidence is encouraging, but more standardized clinical studies are needed to better define its long-term efficacy, optimal formulations, therapeutic concentrations, and clinical applicability in dentistry.