Ultrastructure of the enamel-cementum junction

Abstract

Procollagen is synthesized by secretory odontoblasts and transformed by N-terminal and C-terminal procollagen peptidases into native collagen. Lateral aggregation of collagen fibrils and end-to-end fusion allow fibrils thickening and elongation. Interfibrillar cross-links stabilize the collagen network. Smooth or pitted enamel surfaces play a role in one of the four cemento-enamel junctions (CEJ) detected in the cervical area: (1) the cementum overlapping enamel, (2) the enamel overlapping cementum, (3) the edge-to-edge relationship between enamel and cementum, and finally, (4) a gap between cementum and enamel, the exposed dentin being uncovered. Abrasion, attrition, and erosion at the cervical level lead to the formation of cervical non-carious and carious lesions. In addition, enamel perikymata and dentin sclerosis are structures implicated in tooth wear. Accumulation of cariogenic plaque in the cervical area may contribute to the formation of class V carious lesions. In addition, cervical non-carious surfaces take place in the exposed DCJ.