Pulpo-dentinal complex of the tooth (human, adult).

Stain: Hematoxylin and eosin. At the pulpo-dentinal border the peripheral pulp appears to be a specialized odontogenic region composed of odontoblasts, a cell-free zone and a cell-rich zone; from left to right: Dentin (note striation due to dentinal tubules). (Uncalcified) Light stained predentin. At the transition to dentin numerous small globular calcification areas (irregular and darker stained structures). Columnar odontoblasts (dark stained nuclei) with their cytoplasmic extensions (so-called odontoblastic processes or Tomes' fibers) running through the predentin. Remnants of the light stained cell-free zone of Weil between odontoblasts and pulp connective tissue.