The presence of open dentinal tubules affects the biological properties of dental pulp cells ex vivo.

To investigate the effects of open dentinal tubules on the morphological and functional characteristics of dental pulp cells. Morphological changes in human dental pulp cells that were seeded onto dentin discs with open dentinal tubules were investigated on days 1, 2, 4, and 10 of culture using scanning electron microscopy and fluorescence microscopy. Samples collected on days 1, 3, 6, 8, and 10 of culture were evaluated for cell proliferation rate and alkaline phosphatase activity. Cultured human dental pulp cells developed a columnar or polygonal morphology and monopolar cytoplasmic processes that extended into the dentinal tubules. The cells formed a multilayer and secreted an extracellular matrix onto the cell surface. Scanning electron microscopy and fluorescence microscopy revealed polarized organization of odontoblasts. Cells seeded onto dentin discs proliferated minimally but showed high levels of ALP activity. Dental pulp cells seeded onto treated dentin discs develop an odontoblastlike phenotype, which may be a potential alternative for use in experimental research on dentinogenesis.