Objective: This study investigates the effect of the new synthetic bone grafting material, high pure-phase beta-tricalcium phosphate (Cerasorb(1) M, granule size 500-1000microm), on the osteogenesis process and proliferation marker in bone marrow stromal cells (BMSCs) and its regenerative effect in the periodontal intrabony defects in dogs.
Design: The effect of Cerasorb(1) M (20 and 40mgml(-1) for 1 and 2 weeks) on the proliferation rate of BMSCs was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay on the proliferating cell nuclear antigen (PCNA) by immunoblotting and on alkaline phosphatase level by colourimetric assay. The regenerative effect of Cerasorb(1) M in the periodontal intrabony defects in dogs was investigated by histological and immunohistochemical analysis after 3 and 6 months of grafting.
Results: Incubation of BMSCs with Cerasorb(1) M for 2 weeks led to significant increase in cell proliferation rate, which was associated with increased PCNA. Cerasorb(1) M significantly increased the production of alkaline phosphatase as a marker for the osteogenic stromal lineage and for differentiation and bone formation in BMSCs after 2 weeks. In the histological features and immunohistochemical analysis of PCNA of the intrabony defects in dogs augmented with Cerasorb(1) M, osteoid tissue with a plate-like structure and cellular mesenchymal proliferation besides osteoid islands joined by bridges were observed after 3 months. Six months after the implantation, the Cerasorb(1) M granules were replaced by abundant new plate-like bone besides PCNA-enriched, small, oval-shaped mononuclear cells and multinucleated-giant cells that were attached to newly formed bones. No remains of the Cerasorb(1) M granules could be seen after 3 and 6 months with the newly formed plate-like bones and no histological sign of inflammatory reaction or formation of foreign-body granulomas.
Conclusion: Cerasorb(1) M may induce cell proliferation via induction of PCNA that may induce early osteogenesis and bone formation. Cerasorb(1) M regenerated the bone completely in intrabony defects and that this regeneration was highly associated with PCNA expression in different cell lineage.