Age-related changes in blood capillary endothelium of human dental pulp: an ultrastructural study.

Aim: To describe the ultrastructural changes that occur in pulpal blood capillaries as a result of ageing.

Methodology: Thirty samples of healthy dental pulps were obtained from functional human permanent teeth. Two age groups were examined: young (10-17 years) and old (>60 years). The teeth were extracted under local anaesthesia using mepivacaine without adrenaline (Scandonest 3%, Septodont, Saint-Maur des Fossés, France) and split longitudinally in a bench press. The pulps were gently removed, immersed in fixative solution, sectioned and processed by conventional transmission electron microscopic techniques. Micrographs were taken from the endothelium, and the whole capillary area of each vessel was examined.

Results: In young pulps, the endothelial cell layer was characterized by the presence of numerous pinocytotic vesicles and microvesicles, RER cisterns, free ribosomes, a small Golgi complex, centrioles, microtubules, microfilaments and mitochondria. In the endothelial cell cytoplasm of older pulpal vessels, pinocytotic vesicles and microvesicles, as well as microfilaments, were more numerous. In addition, lipid-like vacuoles, monogranular glycogen granules and extensive Golgi complexes with dilated cisterns were also present. Weibel-Palade bodies were observed in both age groups without showing variations related with age.

Conclusions: The results obtained in capillaries of aged pulpal tissue suggest that the endothelium experiences morphological changes that could be associated with advancing age.