Double Dens Invaginatus with Multiple Canals in a Maxillary Central Incisor: Retreatment and Managing Complications.

Dens invaginatus is a developmental anomaly that often presents a perplexing challenge to the endodontist. It involves the maxillary central incisor less commonly than the maxillary lateral incisor. Double dens invaginatus is even rarer. Herein a unique case of dens invaginatus in a maxillary central incisor is presented. The tooth had an inadequate previous root canal treatment. On retreatment, multiple canals and double dens invaginatus were found. The invaginations were Oehlers type 3b and type 2. The complex morphology was diagnosed and confirmed with cone-beam computed tomography imaging and managed with a combined surgical and orthograde approach. Four canals and a blind sac along with an open apex were found. There were many intercommunications between the canals. During the treatment, a complication of a separated instrument occurred, which was managed successfully. The 1-year follow-up shows successful outcome of the treatment. Dens invaginatus may be more complicated than it seems. It needs meticulous treatment by a specialist. Failure or a delay in referring the case to a specialty setting may further increase the complications. With the advancements in equipment and materials, it is possible to save even severe cases of dens invaginatus.