Endodontic treatment and hypotheses on an unusual case of dens invaginatus.

This work describes a case of "dens invaginatus" and analyzes the possible aspects of this malformation. An unusual type of dens invaginatus was detected in a young patient corresponding to the maxillary lateral incisor and showing extensive periradicular radiolucency and a vestibular fistula. The radiographic and tomographic examination revealed two apices: one wide open in the distal part of the root and the other normally formed in the mesial.