Evaluation of a Microrna Expression Panel and Clinical Outcomes in Periodontitis Following Adjunctive Curcumin or Epigallocatechin-3-Gallate Therapy

Periodontitis is a chronic inflammatory disease driven by microbial dysbiosis and host immune responses, where microRNAs (miRNAs) play regulatory roles. This study evaluated the effects of systemic adjunctive therapies with epigallocatechin-3-gallate (EGCG) or curcumin on gingival miRNA expression and clinical out-comes in patients undergoing conventional periodontal therapy. In a short-term randomized clinical trial, 47 patients with moderate-to-severe periodontitis were stratified into three groups (EGCG, Curcumin, and pro-fessional mechanical plaque removal [PMPR]) and monitored at baseline, three months, and six months. Gingival biopsies were analyzed for miR-138-5p, miR-155-5p, miR-142-3p, and miR-27a-3p expression, alongside standard periodontal indices including probing pocket depth, clinical attachment level, bleeding on probing, plaque index, and OHIP-14 scores. The results demonstrated that both EGCG and curcumin can significantly modulated miRNA expression in gingival tissues, with curcumin inducing a more pronounced decreasing effect on four miRNAs, while EGCG showed increases in miR-138-5p, miR-155-5p, and miR-142-3p at three months. Clinically, EGCG primarily reduced shallow pockets and enhanced pocket closure, whereas curcumin was more effective in reducing deeper pockets, improving clinical attachment, and decreasing bleeding on probing. Both agents achieved higher pocket closure rates compared with PMPR alone. Patient-reported OHIP-14 scores indi-cated improved oral health perception in the adjunctive therapy groups. By six months, only miR-27a-3p re-mained significantly downregulated in the curcumin group, suggesting a sustained regulatory effect. These findings provide the first in vivo evidence that systemic EGCG and curcumin can modulate gingival miRNA expression in periodontitis, translating into measurable clinical benefits. Future research should in-vestigate long-term effects, optimize dosing strategies, and explore molecular pathways linking miRNA regu-lation with periodontal tissue regeneration.