Evaluation of the clinical and volumetric effectiveness of 0.8% hyaluronic acid gel application adjunct to open flap debridment in periodontitis patients with thin gingival phenotype

Hyaluronic acid (HA) is a local chemotherapeutic agent that plays a role in inflammation and wound healing mechanisms. The aim of this study is to evaluate the clinical effectiveness of 0.8% HA gel application adjunct to open flap debridement (OFD) in patients with stage II/III periodontitis who have a thin gingival phenotype. A total of 40 patients were included in the study and were randomly divided into 2 groups: a) OFD + 0.8% HA gel (n=20, test) and b) OFD (n=20, control). Plaque (P), bleeding on probing (BoP), probing pocket depth (PPD), and clinical attachment level (CAL) measurements were recorded at baseline for all individuals. After completion of initial periodontal therapy, areas with PPD ≥ 5mm and horizontal bone loss were identified in patients with a thin gingival phenotype. Gingival phenotype was determined using Hu-Friedy colored gingival probes. Intraoral digital scans were obtained. Relative gingival recession (rGR) measurements were recorded immediately before the surgery. The test group received additional application of 0.8% HA gel during OFS, while the control group received additional application of saline solution. HA application was repeated 4 weeks after OFD in test group. Changes (Δ) in soft tissue volume (mm3 ) and thickness (mm) were measured via using computer software. Evaluations were repeated 3 and 6 months after treatment. When the changes in clinical periodontal parameters at 3 and 6 months were compared, it was found that there was a significant decrease in P (%) in the test compared to the control group (p<0.05); significant clinical attachment gain was determined in the test compared to the control group (p<0.05), and the amount of GR was greater in the control group compared to the test group (p<0.05). On the other hand, although the percentages of BoP and PPD decreased significantly in both groups (p<0.05), the changes did not reach significant between the groups (p>0.05). The changes in gingival volume (mm3 ) and thickness were found to be significantly greater in the control group than that of control (p<0.05). Within the limitations of our study, it was concluded that the additional application of 0.8% HA gel adjunct to OFD in patients with periodontitis having thin gingival phenotype increased clinical attachment gain and reduced the amount of gingival recession and dimensional changes in the gingiva. Therefore, the clinical use of 0.8% HA gel should be recommended in addition to surgical periodontal treatment especially for individuals having thin gingival phenotype where gingival recession is expected. Keywords: Hyaluronic acid, periodontal debridement, periodontitis, phenotype, three dimensional analysis