The purpose of this randomized controlled clinical trial (RCT) was to investigate the clinical and biochemical efficacy of a gel containing PDRN and HA used in association with subgingival re-instrumentation in the treatment of residual periodontal pockets.

The aim of the present study was to investigate the clinical and biochemical efficacy of a gel containing polynucleotides (PDRN) and hyaluronic acid (HA) used in association with subgingival re-instrumentation in the treatment of residual periodontal pockets.

50 patients were enrolled in a randomized, split-mouth clinical trial. For each patient, two teeth with similar residual pockets with probing depth (PD) ≥ 5 mm were selected to receive re-instrumentation with (test) or without (control) the adjunctive use of a PDRN and HA based gel. Differences in changes of PD, gingival recession (REC), clinical attachment level (CAL), modified sulcular bleeding index (mSBI), plaque index (PLI) from baseline to 6, 8, 24, 36 and 48 weeks were analyzed and the frequencies of sites with PD <4 mm at 48 weeks were compared. Furthermore, changes in the dosage of alpha-2-macroglobulin (α2M) and of matrix metalloproteinase-9 (MMP-9) from baseline to 6 weeks were evaluated.

Inclusion Criteria:

• males and females with ≥ 18 years
• stage 3 generalized periodontitis
• 3-6 months after step 1 and 2 of periodontal treatment, at least two non-adjacent teeth showing one residual pocket with probing depth (PD) ≥5, without mobility and without furcation involvement.

Exclusion Criteria:

• full-mouth plaque score (FMPS) and full-mouth bleeding score (FMBS) >20%
• inadequate restorative therapy or malocclusion
• uncontrolled systemic disease
• immunosuppressive therapy or therapy with corticosteroid or with bisphosphonates
• inflammatory and autoimmune diseases of the oral cavity
• history of malignancy, radiation therapy or chemotherapy for malignancy in the last 5 years
• insulin-dependent diabetes;
• smoking (> 10 cigarettes per day)
• drug and alcohol abuse
• pregnant or lactating.