Bone Regeneration Capacity of a Novel Semi-Rigid Shell Barrier System in a Rabbit Model, an In Vivo Study

This study utilized a novel semi-rigid shell barrier system for bone regeneration in a rabbit's calvarial defects. A semi-rigid shell barrier system (SSBS) is comprised of a semi-rigid shell (SRS) and a covering semi-resorbable membrane (SRM). The rabbit's bilateral calvarial defects were divided into five groups and covered with the SSBS (SRS + SRM), the SRM, the d-PTFE (PF), the collagen membrane (CM), and the empty defect (ED) without grafting material. Bone regeneration capacity was evaluated using new bone volume from micro-CT and bone area from histomorphometry at 4 weeks and 12 weeks post-operatively (six defects per group per time point). At 4 and 12 weeks, the SSBS showed significantly highest bone volumes (24.53% ± 1.34%, 35.96% ± 1.51%) and the SRM (25.23% ± 1.75%, 29.25% ± 2.75%), the PF (18.69% ± 1.32%, 29.72% ± 3.00%), the CM (16.93% ± 1.32%, 26.26% ± 1.97%), and the ED (18.39% ± 2.14, 21.63% ± 2.60%). Histomorphometry of the new bone area also showed the same trend as the bone volume. Histological features of the SSBS and SRM showed substantial new bone formation that nearly bridged the defects, demonstrating effective space-maintaining ability and bone infiltration into the material, indicative of osteoinductive properties. The novel semi-rigid shell barrier system proved good in vivo biocompatibility, bone regeneration capacity, and osteoinductive properties.