[Computerized reconstruction of the spatial organization of enamel rods]

Morphometric reliefs on the enamel of the lower incisor of albino rats in correspondence with the prism compaction area during the first third of the ameloblastic modulation phase have been carried out. The reliefs were done on the longitudinal and median fracture plane and on the transversal fracture plane 8 mm from the cervical ansa. Measurements of the diameters of the honeycomb pits were carried out during the deposition phase, following removal of the ameloblastic coat. The data obtained were fed into an Apple Macintosh 512K/800 computer to obtain the geometric reconstruction of an isolated prism, the relations between each portion of the prism and the respective pits and a graphic example of the architectural organization of the enamel. It was shown that each prism consists of three distinct portion, just as there are three types of honeycomb pit. The external orifice of each pit is complementary to the interdigitant portion of the Tomes process, so the study of the pits may be used to evaluate the spatial orientation of the rods and not the morphology of their section. Cross-over between rows of contiguous rods occurs throughout the thickness of the internal enamel layer. The enamel possesses a particularly suitable structure for the transformation of surface type tangential forces into stresses or prevalently compression type.