Adjunctive 0.8% Hyaluronic Acid Gel in Open-Flap Surgery for Thin Gingival Phenotype in Patients With Periodontitis

Evaluation of the Clinical and Volumetric Effectiveness of 0.8% Hyaluronic Acid Gel Adjunct to Open-Flap Surgery in Periodontitis Patients With Thin Gingival Phenotype

The aim of this study is to evaluate the clinical effectiveness of 0.8% hyaluronic acid (HA) gel as an adjunct to open flap debridement (OFD) in periodontitis patients with a thin gingival phenotype.

The primary research question is:

Does the adjunctive use of 0.8% HA gel reduce gingival recession and improve clinical parameters? To answer this, researchers will compare the adjunctive use of 0.8% HA gel to physiological saline in combination with OFD, assessing their effects on clinical outcomes and gingival recession in patients with a thin gingival phenotype.

Participants will:

• Receive 0.8% HA gel application during OFD surgery and a second application at 4 weeks postoperatively.
• Attend follow-up visits at 1, 3, and 6 months after surgery for clinical assessments and measurements.

A total of 40 patients were enrolled in the study and randomly assigned to two groups: (a) OFD + 0.8% HA gel (n = 20, test group) and (b) OFD alone (n = 20, control group). Clinical parameters including plaque (P), bleeding on probing (BoP), probing pocket depth (PPD), and clinical attachment level (CAL) were recorded at baseline. Following initial periodontal therapy, sites with PPD ≥ 5 mm and horizontal bone loss, were identified in patients with a thin gingival phenotype, determined using color-coded gingival probes. Intraoral digital scans were taken, and relative gingival recession (rGR) was recorded immediately before surgery.

During OFD, the test group received adjunctive 0.8% HA gel, while the control group received physiological saline. In the test group, HA gel application was repeated at 4 weeks postoperatively. Changes in soft tissue volume (mm³) and thickness (mm) were measured using specialized computer software. Follow-up evaluations were performed at 3 and 6 months post-treatment.

Inclusion Criteria:

1. Diagnosis of periodontitis (Stage II/III);
2. Presence of horizontal bone loss with at least three adjacent teeth, each exhibiting a probing depth ≥ 5mm and a keratinized tissue width ≥ 2mm on single-rooted teeth;
3. a thin gingival phenotype;
4. Areas with horizontal bone loss without intra-bony defects, where no additional hard and soft tissue augmentation was required
5. a full-mouth plaque score (FMPS) and full-mouth bleeding score (FMBS <20%.

Exclusion Criteria:

• Systemic diseases
• Smokers
• Pregnant or lactating women
• Those who received periodontal treatment within the last 6 months