Calcium phosphates (CaP) of different porosities have been widely and successfully used as scaffolds with osteoblast cells for bone tissue regeneration. However, the effects of scaffold porosities on cell viability and differentiation of human dental pulp cells for dentin tissue regeneration are not well known. In this study, biphasic calcium phosphate (BCP) scaffolds of 20/80 hydroxyapatite to beta tricalcium phosphate ratio with a mean pore size of 300 μm were prepared into BCP1, BCP2, BCP3, and BCP4 of 25%, 50%, 65%, and 75% of total porosities, respectively. The extracts of these scaffolds were assessed with regard to cell viability, proliferation, and differentiation of human dental pulp cells. The high alkalinity, and more calcium and phosphate ions release that were exhibited by BCP3 and BCP4 decreased the viability and proliferation of human dental pulp cells as compared to BCP1 and BCP2. BCP2 significantly increased both cell viability and cell proliferation. However, the cells cultured with BCP3 extract revealed high alkaline phosphatase (ALP) activity and high expression of odontoblast related genes, collagen type I alpha 1, dentin matrix protein-1, and dentin sialophosphoprotein as compared to that cultured with BCP1, BCP2, and BCP4 extracts. The results highlight the effect of different scaffold porosities on the cell microenvironment and demonstrate that BCP3 scaffold of 65% porosity can support human dental pulp cells differentiation for dentin tissue regeneration.
Calcium phosphate (CaP) scaffolds have been widely and successfully used with osteoblast cells for bone tissue regeneration. However, it is necessary to investigate the effects of these scaffolds on odontoblast cells' proliferation and differentiation for dentin tissue regeneration. In this study, three different hydroxyapatite (HA) to beta tricalcium phosphate (β-TCP) ratios of biphasic calcium phosphate (BCP) scaffolds, BCP20, BCP50, and BCP80, with a mean pore size of 300μm and 65% porosity were prepared from phosphoric acid (H2PO4) and calcium carbonate (CaCO3) sintered at 1000°C for 2h. The extracts of these scaffolds were assessed with regard to cell viability and differentiation of odontoblasts. The high alkalinity, more calcium, and phosphate ions released that were exhibited by BCP20 decreased the viability of human dental pulp cells (HDPCs) as compared to BCP50 and BCP80. However, the cells cultured with BCP20 extract expressed high alkaline phosphatase activity and high expression level of bone sialoprotein (BSP), dental matrix protein-1 (DMP-1), and dentin sialophosphoprotein (DSPP) genes as compared to that cultured with BCP50 and BCP80 extracts. The results highlighted the effect of different scaffold ratios on the cell microenvironment and demonstrated that BCP20 scaffold can support HDPC differentiation for dentin tissue regeneration.