Treatment of Residual Pockets in Stage III and IV Periodontitis Using an Oscillating Chitosan Device With or Without a Chitosan Gel—A Randomised Parallel‐Arms Clinical Trial

ABSTRACT Aim To compare non‐surgical subgingival re‐instrumentation with an oscillating chitosan brush (OCB), with and without a novel chitosan hydrogel (LGX), in residual or recurrent pockets in step 3 or 4 of stage III–IV periodontitis patients. Materials and Methods Patients presenting with residual 5–8 mm probing pocket depth (PPD) and modified bleeding on probing (mBOP) scores of 2 or 3 at 3–8 teeth were randomly assigned to treatment with either an OCB alone or OCB combined with LGX gel. Treatment was repeated at 3 months. Examinations took place at baseline (BL) and at 1 (Tp1), 3 (Tp2) and 6 months (Tp3) thereafter. Primary outcomes comprised changes in PPD, mBOP and pocket closure (PC). Results Thirty‐eight patients were included in the analysis. Both treatments resulted in significant PPD and mBOP reductions at all follow‐ups. However, sites treated with adjunctive LGX resulted in significantly greater PPD reductions and higher rates of PC compared to OCB alone (Tp2: PPD reductions 1.55 vs. 1.04, p < 0.001; PC: 67.1% vs. 46.4%, p < 0.001; Tp3: PPD reductions 1.73 vs. 1.33, p = 0.001; PC: 76.8% vs. 60.8%, p < 0.01). Conclusion Adjunctive LGX gel application enhanced the efficacy of repeated subgingival re‐instrumentation with OCB, reducing the need for additional step 3 interventions. Trial Registration ClinicalTrials.gov identification number: NCT05773911, first submitted: 2022‐09‐15 ( https://clinicaltrials.gov/study/NCT05773911 )