Effect of sodium hypochlorite and hyaluronic acid in subgingival re-instrumentation – a randomized clinical trial

BACKGROUND: Adjunctive antimicrobials may improve the outcome of subgingival instrumentation, but due to the lack of evidence no antimicrobial agent is recommended for subgingival re-instrumentation (SRI). The aim of this study was to clinically, immunologically and microbiologically evaluate the potential additional effects of amino-acid sodium hypochlorite (AA-NaOCl) and cross-linked hyaluronic acid (xHA) to SRI at 3 and 6 months. METHODS: At the time point of reevaluation during systematic periodontal therapy, eligible patients were allocated to either control group receiving SRI of residual pockets, or test group with the adjunctive AA-NaOCl and xHA. Per patient 2 study sites were selected and clinical periodontal parameters (PD, CAL, BOP, and pocket closure), immunological biomarkers and 8 major periopathobionts were analyzed at baseline, after 3 and 6 months. Detection of IL-1β and MMP-8 was carried out using ELISA, the abundance of the periopathobionts by qPCR. RESULTS: Improvements in the clinical parameters were demonstrated in all 42 included patients. In the test group an additional PD reduction by 0.50 mm (1.38, 95% CI range: 1.11-1.65 vs. 0.88, 95% CI range: 0.62-1.14; p = 0.008) and CAL gain by 0.57 mm (1.07, 95% CI range: 0.70-1.44 vs. 0.50, 95% CI range: 0.24-0.76; p = 0.017) was found compared to the control group. The percentage of residual pockets decreased by 88.1% (n = 37) in the test, and 38.1% (n = 16) in the control group. There was no significant change in the immunological parameters. The abundance of 5 periopathobionts significantly decreased in the test group. CONCLUSIONS: The adjunctive application of AA-NaOCl and xHA significantly improved the clinical and microbiological outcome 3 and 6 months after SRI. TRIAL REGISTRATION: This trial was registered in the German Clinical Trials Register (ID: DRKS00017415 at 03/06/2019).