[Micromorphological aspects of dentin]

Samples of dentine of healthy teeth were analysed in this study with at the scanning electron microscope. In order to see the morphological changes in the structure of both the dentine and the dentinary tubules, the dentine was observed at different levels according to the distance from the pulp. After the removal of the odontoblasts the predentine appears to be composed only by collagen fibres and is about 15 microns thick. At this level, the dentinary tubules can reach a diameter of 4 microns. This measure decreases progressively in proportion to the distance from the pulp, reaching about 2 microns at a distance of 1 mm, and 1 micron at 2 mm from the pulp. A decrease in the tubular lumina is observed when the peritubular dentine changes from 0.8 to 1 in thickness. The internal surface of the tubules appears smooth and shows the confluence of very thin lateral canaliculi. The dentinary tubules end forming forks which spread out until they enter into contact with the enamel.