Tailoring and characterization of bioactive graft material for alveolar bone preservation and regeneration in fresh extraction sockets of dog model

The objective of this study was to tailor an osteoinductive scaffold for alveolar bone regeneration and around immediately placed implants in extraction sockets of dogs. Tailored amorphous multiporous bioactive glass (TAMP -BG) was prepared and characterized for bioactivity and response of human alveolar bone marrow mesenchymal stem cells (hABMSCs). Extraction sockets of twenty-two male mongrel dogs received TAMP-BG in the right side around implant in the distal socket of the mandibular fourth premolar (P4), while the adjacent empty mesial socket of the same tooth was filled with the same graft. Autologous bone chips were used in the left side. Animals were euthanized at 1, 2, 4, 8 &12 weeks for histological and SEM analyses. SEM/EDX, FTIR and XRD analyses displayed formation of a bioactive hydroxycarbonated apatite layer. TAMP-BG significantly increased proliferation and migration of hABMSCs. Histologically, at the 1^st week, advanced bone healing was shown in TAMP-BG group. At four weeks bone density was significantly higher forTAMP-BG (92.71% ± 1.71) versus control (62.92% ± 2.02) (P = 0.0001).At eight weeks, significant increase in width of buccal plate and height of lingual bony plate was observedfor TAMP-BG grafted implant.The socket orifice width significantly decreased for autologous bone from 1 to 12 weeks (P < 0.001), while it significantly increased for TAMP-BG (P = 0.03). We conclude that TAMP-BG can provide a preservative dynamic microenvironment following extraction up to three months which can be attributed to its unique physico-chemical characteristics.