Adjunctive Antioxidant Benefits in Periodontal Therapy: A Systematic Review and Network Meta‐Analysis

Aim This systematic review evaluated the clinical evidence on the benefits of antioxidant supplementation as an adjunct to conventional periodontal therapy in chronic periodontitis treatment. Materials and Methods A comprehensive literature search was conducted across PubMed, Scopus, Web of Science, and Cochrane Library from inception to February 2025 for relevant randomized controlled trials. A network meta‐analysis was performed, with evidence certainty assessed using CINeMA. Results Nineteen randomized controlled trials (810 patients) were identified and seven antioxidants were evaluated. For probing depth, adjunctive melatonin (standardized‐mean‐difference = 1.88, 95% CI: [1.09, 2.67]), resveratrol (standardized‐mean‐difference = 1.42, 95% CI: [0.33, 2.51]), and green tea (standardized‐mean‐difference = 1.30, 95% CI: [0.03, 2.57]) showed significant improvements over scaling and root planing alone. For clinical attachment loss, melatonin (standardized‐mean‐difference = 2.37, 95% CI: [1.31, 3.44]) and curcumin (standardized‐mean‐difference = 1.37, 95% CI: [0.02, 2.73]) demonstrated efficacy. No antioxidants significantly improved plaque or gingival indices. CINeMA results indicated that some evidence had low to very low certainty. Conclusion Adjunctive melatonin may enhance probing depth reduction and clinical attachment gain, green tea and resveratrol may contribute to reducing probing depth, and curcumin may improve clinical attachment loss. However, owing to limited evidence of low certainty, these conclusions require cautious interpretation.