Figure 1. Light-microscopic views of (a–c) undecalcified ground sections and (d–i) decalcified semi-thin sections stained with toluidine blue. (a) Woven bone formation; (b) cortical bone of the bovine mandible; (c) cortical (CB) and trabecular bone (TB) in the dog mandible; (d) alveolar bone in the rat mandible with cement lines (arrowheads); (e) acellular afibrillar cementum (AAC) at and near the dentino-cemental junction (DCJ) in a human tooth; (f) acellular extrinsic fiber cementum (AEFC) along the cervical root portion of a human tooth; and (g) cellular intrinsic fiber cementum (CIFC) as a repair tissue following root resorption in a human tooth. Note the reversal line (arrowheads) between dentin (D) and CIFC. (h) A soft-tissue inclusion with a central blood vessel in bovine cementum (C); and (i) an osteone-like structure with a central blood vessel (BV) within bovine cementum (C). ES, enamel space; PL, periodontal ligament.