Complex endodontic treatment of an immature type III dens invaginatus. A case report.

AIM To report the endodontic treatment of an immature maxillary central incisor with dens invaginatus. SUMMARY Dens invaginatus is a rare malformation of teeth, probably resulting from an infolding of the dental papilla during tooth development. The present case describes the complex endodontic treatment of a type III dens invaginatus in an immature maxillary central incisor with a necrotic pulp and abscess formation. The initial treatment goal was to achieve apexification of the pseudocanal root and conservative root canal treatment in the main canal. Following 1-year of treatment with calcium hydroxide dressings, radiography revealed a healing response, but no sign of a hard tissue barrier at the apex. Periapical surgery with the placement of a zinc oxide cement (IRM) root-end filling was considered successful at the 4-year follow-up. KEY LEARNING POINTS The complexity of the canal system and open apex in dens invaginatus present a challenge to endodontic treatment. Correct diagnosis and treatment planning are fundamental to treatment of dens invaginatus. Periapical surgery is indicated in cases of unsuccessful apexification in immature teeth with dens invaginatus and nonvital pulp.