Elastic (pseudoelastic tissue in arterioles of the human and dog dental pulp

Formalin-fixed pulps from seven human and five dog teeth were investigated for the occurrence of vascular elastic tissue with special reference to the difference between elastin and pseudoelastica. The latter term denotes structures which show the histochemical and fluorescence microscopic properties of collagen, but also bind the so-called elastica stains. Human aorta, and aorta, lips, tongues and gingiva from dogs served as control material. Whereas conventional elastica stains, in this study represented by orcinol-new fuchsin, only differentiate elastic tissue and collagen, a thiazine red R fluorescence method also permits differentiation between elastin membranes and pseudoelastica. Other methods for light and fluorescence microscopy verified this conclusion. Pseudoelastic fibers/membranes occurred in arterioles of both human and dog pulps, but were more frequent in the latter. The distribution of these elements in the arteriolar walls was different in the human and dog pulp. No elastin elements were observed.