Dentin Pulp Complex: Proceeding of the International Conference on Dentin Pulp Complex 1995 1996 p.316-318
Second Department of Oral Anatomy, Niigata University School of Dentistry, Japan.
Responses of class ‡U major histocompatibility complex (MHC) antigen-expressing cells to cavity preparation were investigated both in the human premolars and molars and the upper first molars of rats. In the human control teeth, class ‡U antigen-expressing cells were widely distributed throughout the dental pulp. The HLA-DR-immunopositive cells in the periphery of the pulp tissue showed dendritic appearance, and some of them being located in the predentin, extending their cytoplasmic processes into the dental tubules. In the control rat molars, OX6-immunopositive cells were located in the subodontoblastic layer and not found in the predentin. Many OX6-immunopositive cells accumulated along the pulp-dentin border 12-24 hours after cavity preparation and extended their cytoplasmic processes into the exposed dentinal tubules. In the human teeth, numerous neutrophil leucocytes migrated deep into the exposed dentinal tubules 24 hours after drilling, while most of the immunopositive cells were situated beneath the exudative lesion. The present results suggested the difference between class ‡U MHC antigen-expressing cells in the human teeth and rat molars in chronological responses to foreign stimuli. It is also confirmed that numerous leucocytes migrate deep into the exposed dentinal tubules when destructive changes are induced in odontoblasts by cavity preparation in the human.