The structure and function of the cemento-dentinal junction in human teeth

The structure and function of the cemento-dentinal junction were studied in human molars by light and electron microscopy. The cemento-dentinal juncti on was an approximately 1-3-mu m-thick layer full of proteoglycans with muc opolysaccharides but containing fewer collagen fibrils than the root dentin and cementum. In places, cemental fibrils crossed the cemento-dentinal jun ction. These fibrils appeared to intermingle with dentinal fibrils. By enzy matic treatment of decalcified specimen with hyaluronidase and trypsin, the cemento-dentinal junction decreased or lost staining affinity to toluidine blue. Prolonged treatment caused the separation of cementum from the root dentin during routine histological processes. These data suggest that the a dhesion of proteoglycans is more important than the intermingling of dentin al and cemental fibrils for the cemento-dentinal attachment.