Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 0 0 2026 08 04 1 18 Mengzheng Chen Department of Stomatology, The Affiliated YangMing Hospital of NingBo University, Yuyao, Zhejiang, China Ke Chen Department of Stomatology, The Affiliated YangMing Hospital of NingBo University, Yuyao, Zhejiang, China Shichun Zhong Department of Stomatology, The Affiliated YangMing Hospital of NingBo University, Yuyao, Zhejiang, China Chaofeng Shen Department of Stomatology, The Affiliated YangMing Hospital of NingBo University, Yuyao, Zhejiang, China 2026 03 23 2026 05 03 The aim of this study was to evaluate the clinical and inflammatory outcomes of minocycline hydrochloride combined with tinidazole in patients with chronic periodontitis. PubMed, Cochrane Library, Embase, CNKI, WanFang Data, and VIP were searched through December 2025 for randomized and nonrandomized controlled studies. Randomized trials were assessed using the Cochrane Risk of Bias tool, while the cohort study was assessed using ROBINS-I. Meta-analysis was conducted using RevMan 5.3. Random-effects models were applied when substantial heterogeneity was present, and sensitivity analyses were performed by excluding the cohort study. Fourteen studies were included. Compared with the control treatment, combination therapy was associated with greater improvements in gingival index (MD=−0.71; 95% CI, −0.77 to −0.65), probing pocket depth (MD=−0.87; 95% CI, −1.07 to −0.66), clinical attachment level (MD=−0.77; 95% CI, −1.06 to −0.49), plaque index (MD=−0.38; 95% CI, −0.45 to −0.32), and sulcus bleeding index (MD=−0.68; 95% CI, −0.96 to −0.40). Changes were also observed in several inflammatory and immune-related indicators, whereas CRP did not differ significantly between the groups. Substantial heterogeneity was present for most outcomes. Overall, minocycline hydrochloride combined with tinidazole may provide additional short-term benefits for patients with chronic periodontitis. Nevertheless, these findings should be interpreted cautiously because of methodological limitations, substantial heterogeneity, incomplete safety reporting, and short follow-up periods. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/4776 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/4776/2381