Dentinogenesis imperfecta type II: ultrastructure of teeth in sagittal sections.

The morphological abnormalities of the teeth of patients affected by dentinogenesis imperfecta type 2 (DI-II) may underlie the difficulties with the clinical restoration of such teeth. We therefore performed a scanning electron microscopy (SEM) study of four permanent first mandibular molars of four DI-II patients with periapical pathosis. The teeth were prepared for SEM evaluation by standard methods. In the crown, the enamel presented a highly irregular surface with a number of cracks and crevices. In some places, only granular remains of the enamel were found, while in other parts of the crown, the enamel was absent. SEM examination revealed the structural changes responsible for the lower enamel's hardness and resistance to attrition, and for tooth wear, while the structural changes in the dentin may explain the failure of some adhesive restorative materials. This SEM study thus revealed structural defects which underlie the problems of attrition and restoration loss found in patients with this genetic dental condition.