OR32 - Subcutaneous Osteoinduction: Bioceramic Sealer-Driven Bone and Cartilage Formation

Objective: To evaluate subcutaneous reaction of Bioceramic sealer (BC, Brasseler, Savannah, GA, USA) after implantation in rat subcutaneous tissues.

Methods: Eighteen male Wistar rats weighing 160±10 grams were selected. Dorsal trichotomies were manually performed, and each animal received implants of BC sealer, AH₂₆ sealer, and sham operation as a control group. The animals were sacrificed at 7, 21, and 30 days after implantation. Specimens were processed for histomorphological and immunohistochemical examination using caspase 3, KI67, BMP₂, and osteopontin as biomarkers. Statistical analysis was performed, and p-value was set as significant at 0.05.

Results: After 7 days, there was a significant inflammatory infiltrate, congested blood capillaries, and expression of caspase 3 in BC and AH₂₆ groups compared to the control group (p <.05). BC group exhibited early remarkable cell proliferation (Ki-67), angiogenesis (CD34), and significant expression of BMP₂ and osteopontin. After 21 days, sham group exhibited normal tissue architecture, while AH₂₆ group had foreign body reaction with many giant cells at the interface area. BC group showed formation of cartilage with peripheral ossification. At 30 days, AH₂₆ group had many multinucleated giant cells with intracytoplasmic black particles of the engulfed material. The BC group showed either back to normal architecture (50%), foreign body giant cells (~16.7%), or bone with bone marrow formation (~33.3%).

Conclusion: BC sealer exhibited a strong osteoinductive potential when implanted in the subcutaneous tissues of rats, resulting in cartilage and bone formation as indicated by the expression of BMP₂ and osteopontin.