[Dentinogenesis imperfecta: a structural and ultrastructural study].

Abstract

Histopathology of dentinogenesis imperfecta shows a haphazard distribution of dentinal tubules as well as changes in their diameters, sometimes narrowed, sometimes widened. These tubules appear as bundles or sheaves. This kind of dentine is often similar to secondary (also called tertiary) dentine, only mantle dentine preserving a normal structure. There is a complete obliteration of the pulp chamber and an almost complete obliteration of the root canal. Through SEM, the tubules appear to be few in number, their diameters are small and their fine ramifications are intricate through all planes. An heterogenous intertubular substance can be seen. Through TEM, collagenous fibers appear to be uncalcified or incompletely calcified, with a haphazard distribution. There are wide differences in the sizes of crystals and numerous spaces appear between crystals and collagen. Differences between the ultrastructure of human dentinogenesis imperfecta and the dentine of some lower vertebrates are clearly pointed out.