Electron microscopy of cells displaced into the dentinal tubules due to dry cavity preparation.

Using dogs' teeth, cells displaced into the dentinal tubules due to dry cavity preparation were observed using electron microscopy. In order to obtain adequate fixation a new local-perfusion method was employed. Most of the cells which moved into the dentinal tubules were odontoblast nuclei and partly neutrophilic leukocytes and erythrocytes. Not only odontoblast nuclei but also cytoplasmic organelles, such as mitochondria, rough endoplasmic reticulum, free ribosomes, and lysosomes were displaced into the tubules. The weavings of dentinal fibers in the tubules were observed in some areas.