Inter-odontoblastic fibres in human dentine observed by scanning electron microscopy.

Crowns of healthy premolars with closed apical foramina were fixed, resin-impregnated and freeze fractured. Fragments were critical-point dried and examined by scanning electron microscopy. Radial inter-odontoblastic fibres with a diameter of 0.1-0.7 micron were observed. Most of these radial fibres originated from the odontoblast cell body, but some of them arose from the pulp. Both of them entered the predentine at the rim of dentinal tubules and their branches formed the fibrous network of predentine. The odontoblast processes had only a few short side branches at the level of predentine. Some fibrils were observed in the mineralized intertubular dentine, as well.