Comparative analysis of clinical, patient-centered, and COL1A1 gene expression outcomes following coronally advanced flap with xenogeneic collagen matrix versus connective tissue graft in maxillary gingival recession: A parallel-arm, single-blinded randomized controlled clinical trial.

Objectives: Coronally advanced flap (CAF) combined with connective tissue graft (CTG) is a gold standard for root coverage but is limited by donor site morbidity. The aim of this study was to compare the clinical, patient-centered, and molecular outcomes of CAF combined with xenogeneic collagen matrix (XCM) versus CTG in the treatment of maxillary gingival recession defects, with a focus on COL1A1 gene expression. Methods: This randomized controlled trial included 40 patients with Cairo RT1 gingival recession defects, allocated into two groups: CAF + XCM (test; n = 20) and CAF + CTG (control; n = 20). Clinical parameters including probing pocket depth (PPD), clinical attachment level (CAL), width of keratinized tissue (WKT), recession height (RH), recession width (RW), and mean root coverage (MRC) were evaluated at baseline and 6 months. Root sensitivity was assessed at baseline and 6 months, while postoperative pain was recorded at 24 h, 7 days, and 14 days. Surgical duration was measured, and COL1A1 gene expression in gingival crevicular fluid was quantified using real-time quantitative PCR. Results: Both groups showed significant clinical improvement and upregulation of COL1A1 expression at 6 months (p < 0.05). Intergroup differences in clinical and molecular outcomes were not statistically significant. However, the XCM group had significantly shorter surgical time and lower postoperative pain scores (p < 0.05), indicating improved patient comfort. Conclusions: XCM offers comparable clinical and molecular outcomes to CTG with the added benefits of reduced surgical time and morbidity, making it a viable, patient-friendly alternative in the management of gingival recession.