Soft-Tissue Volume Augmentation at Dental Implant Placement Using Collagen-Based Matrix Characterized by Oriented Open Pore Structure: A Retrospective Study with a Median Follow-Up of 17 Months.

Background/Objective: Soft-tissue volume augmentation with gingival grafts enhances implant-prosthodontic esthetics by maintaining or reconstructing a convex contour of the vestibular mucosa. However, it presents disadvantages related to donor site, surgical complexity, and post-procedural discomfort. This study evaluated clinical performance of a native porcine-derived collagen-elastin matrix with uniquely oriented porous structure for soft-tissue volume augmentation at single implant sites. Method and Materials: Soft-tissue augmentation was performed at sites of a single implant, which underwent immediate, early, or late loading protocols. Implant success, its survival, and mucosal health status including change in tissue thickness acquired through 3D scans of casts prepared from impressions before and after tissue augmentation were evaluated. Biocompatibility of the collagen matrix (CM) was assessed through histological analyses. Results: Forty-five patients received 50 implants with simultaneous augmentation using CM. At the last follow-up (mean 22.1 ± 15.0 months), the peri-implant soft tissue was healthy and stable, and all implants were surviving and successful. Tissue thickness change at augmented sites did not vary with time interval between pre- and post-treatment, indicating stability of augmentation. Soft-tissue biopsies (n = 3) showed healthy peri-implant soft tissue with good vascularization and no inflammation. Conclusions: This retrospective analysis demonstrated good clinical performance and high biocompatibility of CM for soft-tissue volume augmentation around dental implants.