Nonsurgical endodontic treatment of Type III dens invaginatus in maxillary canine: an 18-month follow-up.

Dens invaginatus (DI) is a developmental variation resulting from an infolding of the outer enamel surface of a tooth into the interior. The greatest difficulty in the endodontic treatment of DI is in locating the rudimentary root canal, because of the atypical internal morphologic complexity. Invagination may also restrict sufficient cleaning and shaping.