Curcumin in oral health: mechanisms, clinical evidence, and delivery strategies

Curcumin, a polyphenolic compound derived from the turmeric rhizome (Curcuma longa), has attracted significant interest in dentistry and oral medicine because of its multifaceted therapeutic properties. In particular, curcumin exhibits potent anti-inflammatory, antioxidant, and antimicrobial activities that are relevant to a wide spectrum of oral diseases. We conducted a narrative search of PubMed (2000-2025) using iterative keyword combinations related to curcumin and oral diseases/mechanisms, screened reference lists, and selected studies on the basis of their relevance to oral pathobiology, delivery systems, and clinical/translational outcomes. This narrative review summarized the current knowledge concerning the molecular mechanisms of curcumin and its clinical applications in oral health. We outlined how curcumin modulates key inflammatory pathways and oxidative stress responses, and how it exerts broad-spectrum antimicrobial effects against oral pathogens. We detailed the efficacy of curcumin in specific oral conditions, including periodontal diseases, dental caries, recurrent aphthous stomatitis, oral lichen planus, oral submucous fibrosis, oral candidiasis, radiation/chemotherapy-induced oral mucositis, and oral cancers. In each context, we highlighted evidence from <i>in vitro</i> studies, animal models, and clinical trials, and noted the benefits of curcumin, such as reduced inflammation, enhanced healing, microbial inhibition, and in some cases outcomes comparable to those of standard therapies. Across conditions, curcumin shows adjunctive benefit: In periodontal disease, it reduces plaque and gingival inflammation comparable to chlorhexidine and improves probing outcomes when added to scaling and root planing; in recurrent aphthous stomatitis, it reduces pain and ulcer size with steroid-like efficacy; in radiotherapy/chemotherapy-induced oral mucositis, it delays onset and decreases severity; in oral candidiasis, it decreases fungal burden and enhances photodynamic therapy; and in oral squamous cell carcinoma early clinical studies show modulation of inflammatory cytokines and the oral microbiome. Various delivery systems developed to overcome the poor bioavailability of curcumin-from mouthwashes and gels to nanocarriers and mucoadhesive formulations-are reviewed. Although many studies reported promising results with minimal toxicity or side effects, there were study limitations such as small sample sizes, variability in formulations, and the pharmacokinetic properties of curcumin. Overall, the reviewed data support the role of curcumin as a safe, formulation-dependent adjunct-not a stand-alone therapy-in oral medicine.