β-Tricalcium Phosphate Induces Apoptosis on Dental Follicle Cells

Dental stem cells represent a good treatment option in regenerative dentistry. Regeneration of large bone defects can be achieved by a cell-based therapy consisting of osteogenic progenitor cells, such as dental follicle precursor cells (DFCs), in combination with bone substitute material used as a scaffold. A previous trial had shown that β-tricalcium phosphate (TCP) improves the osteogenic differentiation of DFCs. In the present trial, we investigated the attachment, survival, and proliferation of DFCs on TCP in more detail. A high initial cell number was required for the adhesion, attachment, and sufficient proliferation of DFCs on a TCP scaffold. The TCP scaffold released fine soluble particles enriched in TCP eluates that induced cell death and showed typical characteristics of programmed cell death (apoptosis) in DFCs. During cultivation on the TCP scaffold, DFCs showed a highly upregulated expression of antiapoptotic genes but a downregulated expression of proapoptotic markers. In conclusion, TCP supports osteogenic differentiation in DFCs but also induces programmed cell death. Our data suggest that surviving DFCs avoid programmed cell death by inducing antiapoptotic genes.