Changes in the pulpal vasculature during inflammation.

The reaction and vascular changes of pulpal vessels in experimentally induced acute and chronic pulpitis in dog teeth were investigated using corrosion resin casts and scanning electron microscopic examination. Following a cavity preparation without water cooling, increased permeability of blood vessels occurred in the primary stage of acute pulpitis. This was evidenced by the extravasation of resin in the vascular resin casts. This phenomenon was found initially in the venular network and in the post capillaries of the capillary network located under the dentin. In the resin casts of the vascular network underneath the cavity morphological change was minimal. This is in contrast to an expanded and tortuous granulomalike vascular network which was found around an abscess in chronic pulpitis.