Bilayered Porcine Derived Collagen Membranes for Soft Tissue Augmentation in the Oral Cavity

Soft tissue augmentation in the oral cavity is limited by mechanical loading, salivary enzymes, and rapid degradation of collagen-based biomaterials. Porcine-derived collagen membranes (PDCMs) may provide an alternative to autografts, but their clinical performance is influenced by membrane architecture, crosslinking, and the surgical environment. This study evaluated the long-term biocompatibility, degradation behavior, and soft tissue healing outcomes of two novel crosslinked PDCMs compared with an established noncrosslinked bilayer membrane in a canine mandibular defect model. Standardized full-thickness mandibular soft tissue defects were created in n=24 beagles and treated with a bilayer PDCM with high crosslinking (HXL), a bilayer PDCM with low crosslinking (LXL), or a predicate bilayer membrane (Mucograft, MG). Untreated defects served as controls. Animals were euthanized at 4, 8, and 12 weeks. Qualitative and semiquantitative analyses assessed membrane presence, inflammation, and subepithelial healing, while membrane thickness was quantified across timepoints. All membranes supported successful healing with decreasing inflammation over time. At 4 weeks, MG demonstrated greater membrane thickness (p = 0.023) and inflammation (p = 0.004) than LXL. At 8 weeks, both HXL and LXL showed reduced membrane presence relative to MG (p = 0.001), and this difference persisted at 12 weeks (p = 0.018). At 12 weeks, LXL achieved superior subepithelial healing compared with MG (p = 0.047), with more organized collagen and improved integration. Overall, LXL provided a favorable balance of stability, integration, and biocompatibility, supporting coordinated soft tissue remodeling.