This study investigated the effectiveness of hyaluronic acid gel in enhancing soft tissue healing after periodontal surgery for residual pockets (5-8 mm). A 3-month prospective, randomized controlled trial included 26 patients from Aristotle University's Postgraduate Periodontology Clinic who had completed initial periodontal therapy and exhibited at least one residual pocket.

Participants were randomly assigned to an experimental group (receiving 0.6 ml hyaDENT BG hyaluronic acid gel) or a control group (receiving 0.6 ml saline). Before surgery, gingival crevicular fluid (GCF) samples were collected for inflammatory and healing biomarkers (PGE-2, MMP-9, IL-1β, VEGF, EGF), analyzed using ELISA. Surgery was performed at sites with persistent pockets, and follow-ups occurred at 14 days and 3 months postoperatively.

Healing was assessed using the Landry, Turnbull, and Howley Wound Healing Index (WHI). Clinical parameters, including probing pocket depth (PPD), bleeding on probing (BoP), clinical attachment level (CAL), and plaque index (PI), were measured at 3 months, with treatment success defined as PPD ≤4 mm without BoP. Patient-reported outcomes, such as pain, swelling, chewing, speech, and aesthetics, were evaluated using a Visual Analog Scale (VAS).

The current study aimed to investigate the effectiveness of hyaluronic acid gel in accelerating soft tissue healing following periodontal surgery for the treatment of residual periodontal pockets with a depth of 5-8 millimeters.

A prospective, randomized controlled clinical study with a duration of 3 months was designed. Twenty six (26) patients attending the Postgraduate Periodontology Clinic of the Dental School at Aristotle University of Thessaloniki (AUTH). These patients had completed Steps 1 and 2 of initial causative periodontal therapy and had at least one residual periodontal pocket with a depth of 5-8 mm during the re-evaluation (according to the 2018 classification of periodontal and peri-implant diseases). Clinical measurements and radiographic evaluation were performed using the parallel technique, and patients received oral hygiene instructions as part of the initial assessment. Surgical intervention was scheduled two weeks later at sites showing a periodontal pocket depth of 5-8 mm during re-evaluation. The participants were randomly assigned to one of two groups: the experimental group, which received surgical treatment with 0.6 ml of hyaDENT BG hyaluronic acid gel inside the flap, and the control group, which received surgical treatment with 0.6 ml of normal saline (placebo). Prior to surgery, two sterile paper strips (Periostrips) were used to collect gingival crevicular fluid (GCF) samples for inflammatory biomarkers (PGE-2, MMPs-9, IL-1β) and markers for angiogenesis and epithelial cell proliferation (VEGF, EGF). Biomarker concentrations were assessed using the Elisa technique. The patients were followed up on the 14th day and at 3 months post-surgery. GCF samples were taken from the same periodontal pocket on the 14th day (after suture removal) for the evaluation of VEGF and EGF, and at 3 months for the study of PGE-2, MMP-9, and IL-1β. Clinical re-assessments were conducted at 3 months, including measurements of pocket depth (PPD), bleeding on probing (BoP), clinical attachment level (CAL), and plaque index (PI). Treatment success was defined as a pocket depth of ≤4 mm without bleeding on probing at the initial lesion sites. Soft tissue healing was evaluated macroscopic using the Landry, Turnbull, and Howley Wound Healing Index (WHI). Postoperative pain, swelling, chewing and speaking ability, and appearance were assessed using a Visual Analog Scale (VAS).

Inclusion Criteria:

• the presence of at least one residual pocket with depth 5-8mm at the follow - up examination, after the completion of Steps 1 and 2 of the initial etiological periodontal therapy.

Exclusion Criteria:

• severe systematic disease of patients by which a surgical procedure cannot be performed (e.g., uncontrolled diabetes, chemotherapy, immunosuppressive therapy, use of bisphosphonates)
• previous periodontal surgery at the site of the lesion
• antibiotic intake in the last one month before treatment
• patients who smoke more than 10 cigarettes per days
• use drugs or alcohol
• women in pregnancy or lactation period
• periodontal lesions indicated for regeneration (3-walled, craters) were excluded from the study and were threated accordingly