Performance of a multiphase bioactive socket plug with a barrier function for alveolar ridge preservation

Abstract The multiphase bioactive socket plug is designed to overcome the natural healing process of the extraction socket by maintaining the three-dimensional (3D) volume of extraction sockets, particularly in sockets with wall defects, and later provide sufficient alveolar bone volume for implant placement. The study aimed to fabricate and evaluate the physical, mechanical, and biological performance of a multiphase bioactive socket plug in vitro. A multiphase bioactive socket plug was fabricated through freeze-drying and layer-by-layer assembly, comprised of a base serving as a scaffold, a central portion for promoting bone regeneration, an upper buccal portion for maintaining alveolar socket dimension with a covering collagen membrane (Memb) on the top and upper buccal surface to prevent soft tissue infiltration. The multiphase bioactive socket plug (BP) as the experimental group, and a pure collagen plug (CP) as a control group were investigated and compared in physicochemical and in vitro biological properties. Scanning electron microscopy (SEM), radiograph and Energy-dispersive spectroscopy (EDS) mapping confirmed the four-part BP was successfully assembled and fabricated. Swelling rate analysis indicated that BP, CP, and Memb reached swelling equilibrium within 1 hour. BP exhibited a high percentage of the remaining weight in collagenase solution (68.81 ± 2.21% on day 90) and sustained calcium ion release, reaching the maximum 0.13 ± 0.04 mmol/L on day 14. In biological assays, BP exhibited excellent cell proliferation (The OD value increased from 0.02 on day 1 to 0.23 on day 21.). The BP group exhibited higher alkaline phosphatase (ALP) activity and Osteocalcin (OCN) content compared to the CP group within 21 days. Memb and BP exhibited outstanding barrier function, as evidenced by Hematoxylin and eosin (H&E) staining. In summary, the multiphase bioactive socket plug represents a promising scaffold for alveolar ridge preservation application.