Acellular cementum in the tooth (longitudinal segment of coronal half of root; high magnification; human, adult)

Stain: Hematoxylin and eosin. From left to right: periodontal ligament with collagen fibers; flattened cementoblasts followed by a thin seam of pink cementoid; darker stained acellular cementum, the so-called acellular extrinsic fiber cementum as collagen fibers protrude from the periodontal ligament into cementum; vertical course of incremental lines (of Salter) with densely aggregated, horizontally oriented Sharpey's fibers are present; note the absence of cementocytes; dense stained dentinocemental junction (outmost right); and dentin.