Development of a novel bifunctional and volume-stable soft tissue substitute for peri-implant soft tissue and bone integration.

The collagen-based soft tissue substitutes are popularly used instead of autogenous connective tissue grafts (CTG). However, it has some drawbacks, such as rapid degradation and compromised volume stability. The novel bifunctional and volume-stable soft tissue substitute (BVSS), based on polyvinyl alcohol (PVA), biphasic calcium phosphate (BCP), and fish collagen was developed to overcome those mentioned problems. The physicochemical and mechanical properties were characterized and compared using scanning electron microscopy (SEM), degradation and swelling behavior, Fourier transform infrared spectroscopy(FT-IR), differential scanning calorimetry (DSC), and tensile testing, respectively. The biocompatibility was evaluated with fibroblast and osteoblast cells. The SEM images showed a rough and porous surface with interconnected porous structures. The 3% PVA-based scaffolds showed a suitable degradation rate in collagenase (40%-50%), more than 5% PVA (20%-30%) in 8 weeks. All prepared BVSS presented high water absorption rates. The 5% PVA-based scaffolds showed higher tensile strength than the 3% PVA-based scaffolds. The 3% 8:2 and 5% 8:2 demonstrated good cell proliferation and adhesion of both fibroblast and osteoblast cells on the scaffold. The prepared BVSS is compatible with hard and soft tissues and maintains a volume-stable character, making it ideal as a bifunctional peri-implant tissue scaffold.