Meta-analysis of 16 trials shows no added benefit of subgingival chemical irrigation for periodontitis

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Clinical oral investigations Published May 13, 2026 Medically reviewed May 13, 2026 Study authors: da Silveira Marcela Iunes, Maciel Clarissa Carvalho Martins, Grant Melissa M, Chapple Iain L C, De M… PubMed ↗ DOI ↗ By Dr. Ji-eun Park, MD · Brain, Mind & Pain

Key Takeaway

Note that subgingival chemical irrigation offers no proven benefit over non-surgical periodontal treatment alone.

This systematic review and meta-analysis examined the role of subgingival irrigation with chemical agents as adjuvants to non-surgical periodontal treatment in patients with periodontitis. The review synthesized data from 16 randomized clinical trials comparing these adjunctive strategies against non-surgical periodontal treatment alone. The chemical agents assessed included povidone-iodine, essential oils, chlorhexidine, ozonated water, and boric acid. The setting of these trials was not reported in the source data.

Key findings indicated that subgingival irrigation did not provide additional benefit for probing pocket depth, clinical attachment level, or bleeding on probing. Statistical analysis showed P values greater than 0.05 for all secondary outcomes, suggesting no significant difference between the intervention and control groups. The absolute numbers and specific effect sizes were not reported in the source material.

The authors noted that most studies raised some concerns regarding the risk of bias, with 2 studies showing a high risk of bias. Consequently, evidence levels are classified as low to very low. Funding or conflicts of interest were not reported. These limitations underscore the need for cautious interpretation of the results.

Study Details

Study typeMeta analysis

EvidenceLevel 1

PublishedMay 2026

PMID42126682

View Original Abstract ↓

OBJECTIVE: This systematic review aims to assess the efficacy of chemical agents (CA) in subgingival irrigation as an adjunct to non-surgical periodontal treatment (NSPT) in the treatment of periodontitis. METHODS: Search strategies were developed for MEDLINE via PubMed, Web of Science, and LILACS databases for publications up to March 2025. Risk of bias was assessed according to the RoB 2.0 tool. Random-effects meta-analyses were conducted for clinical attachment level (CAL), probing pocket depth (PPD), and bleeding on probing (BOP). RESULTS: From 1244 studies initially screened, 16 randomized clinical trials were included for qualitative and quantitative analyses. Studies assessed the effects of the following chemical agents: Povidone-iodine (PVP-I), Essential Oils (EOs); Chlorhexidine (CHX), Ozonated water (OW) and Boric Acid (BA). Overall, the meta-analysis showed that the adjunctive use of CA as subgingival irrigation did not provide additional benefit in PPD reduction, CAL gain, and BOP compared with controls (P > 0.05). Most studies raised some concerns with risk of bias, and 2 showed a high risk of bias. CONCLUSION: Adjunctive use of chemical agents in subgingival irrigation during NSPT for periodontitis patients does not appear to provide additional benefit over NSPT alone, although evidence levels are low to very low. CLINICAL RELEVANCE: CA are frequently used as adjuncts to NSPT, despite uncertainty regarding their real clinical contribution. The findings of this study help clinicians make more evidence-based decisions and avoid unnecessary use of adjunctive subgingival irrigation strategies during periodontal treatment.