The present invention provides a dentinogenesis inducer and dentinogenesis pulp-capping material, which are effectively used for formation (regeneration) of dentin. The present invention also provides a method of producing odontoblasts useful for dental regenerative therapy and the application of the obtained odontoblasts. The dentinogenesis inducer and the dentinogenesis pulp-capping material of the present invention are both characterized by the use of an HMG-CoA reductase inhibitor as an active ingredient. Additionally, odontoblasts can be produced by culturing cells capable of differentiating into odontoblasts in the presence of the HMG-CoA reductase inhibitor.
