Pulp Cells Response and Dentine Regeneration

This work was carried out to investigate Biodentine as dentin substitute by studying its interactions with dental pulp tissues. The interaction of Biodentine with pulp cells was investigated on cell cultures from human third molars (30000cells/cm²). Samples of the material, prepared according to the manufacturer's instructions, were incubated in DMEM medium at determined surface/medium volume ratios. After 24 hours, these conditioned media were incubated with injured or intact cells. Transforming Growth Factor-β1 (TGF β1) quantification in the supernatants was performed with ELISA test. Differentiation and mineralization markers were investigated after incubation of cells with Biodentine extracts for 4 weeks. Immature third molars were used to investigate the effect of Biodentine on dentin regeneration using the human entire tooth culture model. A cavity with pulp exposure was performed per tooth under sterile saline coolant and Biodentine was applied as a pulp capping material. The teeth apical part was dipped in DMEM medium and cultured for different periods. After 24 hours incubation with Biodentine extracts, a significant induction of TGF β1 secretion from injured cells was observed. Interestingly, after 4 weeks, the cultured cells expressed odontoblastic markers and showed mineralized nodules formation. These results were confirmed in the entire tooth culture model. Indeed, after tooth pulp capping with Biodentine, mineralized foci including sequestered cells were observed after 14 days just beneath the material in the wound area and this increased after 4 weeks. Collagen I, Osteonectin and Dentin Sialoprotein were expressed in the mineralized matrix and in the sequestered cells which also expressed Nestin. Taken together, these results show that Biodentine induced odontoblast differentiation via induction of TGF β1 secretion by injured cells. The resulting matrix has the dentin molecular characteristics and the matrix-sequestered cells express the odontoblast molecular markers. These results strongly suggest that Biodentine is bioactive and stimulates dentin regeneration.