β-Tricalcium phosphate promotes cell proliferation, osteogenesis and bone regeneration in intrabony defects in dogs

Abstract

Objective This study investigates the effect of the new synthetic bone grafting material, high pure-phase β-tricalcium phosphate (Cerasorb ® M, granule size 500–1000 μm), 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 ® M (20 and 40 mg ml −1 for 1 and 2 weeks) on the proliferation rate of BMSCs was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2 H-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 ® 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 ® M for 2 weeks led to significant increase in cell proliferation rate, which was associated with increased PCNA. Cerasorb ® 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 ® 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 ® 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 ® 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 ® M may induce cell proliferation via induction of PCNA that may induce early osteogenesis and bone formation. Cerasorb ® M regenerated the bone completely in intrabony defects and that this regeneration was highly associated with PCNA expression in different cell lineage.