TNF and pulpitis: TNF-α is released in the periapical inflammatory region and BMP9 can partially restore the inhibitory effect of TNF-α on osteoblast differentiation of dental papilla cells.17 No studies evaluate BMP9 and dental pulp inflammation, however, the correlation between BMP9 and pulpitis requires further discussion, which will provide not only a basis for understanding the molecular regulatory mechanism in the occurrence and development of pulpitis, but a more comprehensive basic research reference for BMP9 as a biological factor in new bioactive molecular pulp capping materials.