Therapeutic Effects of Curcumin on Different Types of Oral Diseases: Evidence from Preclinical Animal Studies and Clinical Trials

Background: The present study aims to review and summarize the therapeutic effects of curcumin on different types of oral diseases, along with the mechanisms of action based on evidence. Methods: A comprehensive review of preclinical animal studies and clinical trials published from 2014 to 2024 in PubMed, Scopus, ScienceDirect, Web of Science, Wiley Online Library, and Google Scholar was conducted. Risk of bias was assessed using SYRCLE’s RoB tool for preclinical animal studies and Cochrane RoB 2 for clinical trials. Results: Based on the review, we highlight that curcumin has strong potential as a promising adjuvant therapeutic agent for various oral diseases, such as periodontal diseases (gingivitis and periodontitis), recurrent aphthous stomatitis, oral mucositis, oral lichen planus, oral leukoplakia, oral submucous fibrosis, and oral cancer, as evidenced by both preclinical animal studies and clinical trials. These effects are attributed to curcumin’s reported anti-inflammatory, antioxidant, antifungal, antimicrobial, immunomodulatory, and anticancer activities. We also found that no significant adverse side effects were reported from subjects given curcumin compared with those given conventional therapy. However, although curcumin offers significant therapeutic effects on oral diseases, we found limitations in clinical trials of curcumin on some diseases, especially oral cancer. Therefore, future studies related to clinical trials on some oral diseases with rigorous methods may be warranted. Conclusion: Curcumin seems promising as a therapeutic agent for oral diseases. However, further clinical trials with more rigorous methods and larger samples are strongly needed.