Iloprost Induces Tertiary Dentin Formation

• Iloprost significantly stimulated the expression of vascular endothelial growth factor and osteo-/odontogenic marker in human dental pulp cells.
• Iloprost enhanced pulp cells alkaline phosphatase enzymatic activity and mineral deposition.
• Marked increase in tertiary dentin formation was observed in the iloprost-treated group in tooth injury model in rats.

IntroductionProstacyclin (PGI2), a member of the prostaglandin family, can promote angiogenesis and cell proliferation.MethodsIn this study, the effect of the application of a PGI2 analog (iloprost) on dentin repair was examined in vitro and in vivo.ResultsIloprost significantly stimulated the expression of vascular endothelial growth factor and osteo-/odontogenic marker messenger RNA in human dental pulp cells (HDPCs) under osteoinductive conditions in vitro. In addition, iloprost enhanced HDPC alkaline phosphatase enzymatic activity and mineral deposition. An in vivo study was performed using a rat molar mechanical pulp exposure model. After 30 days, histologic analysis revealed that there was a dramatic tertiary dentin formation in the iloprost-treated group compared with the calcium hydroxide and the untreated control groups. Furthermore, vascular endothelial growth factor protein expression in dental pulp tissue was increased in the iloprost-treated group as determined by immunohistochemical staining.ConclusionsTaken together, the present study, for the first time, shows that iloprost induces the expression of osteo-/odontogenic markers in vitro and promotes angiogenic factor expression and enhances tertiary dentin formation in vivo. This implies the potential clinical usefulness of iloprost in vital pulp therapy.