A different approach to immersion fixation of human dental pulp and odontoblast processes.

A low-speed diamond-edge rotary saw microtome was used to prepare freshly extracted human teeth for fixation. The teeth were sliced transversely 900 microns thick using saline as a coolant; the slices were immersed in glutaraldehyde fixative within 10 min of tooth extraction. After flat-embedding in Araldite, sections were reduced to 70 microns thickness and examined with light microscopy. Selected areas were processed for electron microscopy. In the light microscope, the entire pulp appeared to be well fixed. Electron microscopy showed that the contents of most of the tubules near the predentine were well fixed and microfilaments and microtubules were present in odontoblast processes. The quality of fixation with this method was at least as good as other methods applicable to teeth with the advantage that the integrity of the entire dental pulp was preserved.