Afibrillar cementum By the origin of the matrix fibers Extrinsic fiber (from PDL fibroblasts) Intrinsic fiber (from cementoblasts) Mixed fiber (contains both of the above) Examples: Acellular, afibrillar cementum(coronal cementum of human teeth) Mostly composed of mineralized ground substance. Free of cells or fibers.
In the cemento-enamel junction, the cementum is overlapping enamel ( a ). In ( b) cement and enamel are continuous, forming an edge-to-edge structure. In ( c ), gaps are obvious between root cementum and exposed dentin. The 4th missing figure would be related to enamel overlapping dentin, a very seldom case
Afibrillar cementum is a compact coating which could stretch from the acellular cementum onto the tooth enamel. The cellular cementum is the thickest coating, overlaying the bottom, two third of the tooth root.
