Apex of the tooth in osseus socket - alveolus; longitudinal section; human, adult

Stain: Hematoxylin and eosin. From top to bottom: apex region with two tips of dentin covered with cement (darker stained rim; left and right side); note at right tip a dark calcified spot (free cementicle); centrally pulp canal between the tips filled with connective tissue containing blood vessels and a thick bundle of nerves; in the middle a wide spaced apical foramen where pulpal connective tissue continues into the periodontal ligament (left and right side); bundles of collagen fibers (apical fibers) present between cellular cementum and the osseous alveolar wall (bottom left and right).