From a technical point of view, root canal treatment of invaginated teeth is not an easy task due to the complexity of their canal morphology. In this article, three cases are reported, for which two different treatment approaches were applied. One case was treated following the conventional approach, whereas the other two were treated applying the conventional approach together with endodontic surgery. Follow-up examinations showed successful clinical and radiographic results in the three cases mentioned in this article. Schlagwörter: cone beam computed tomography, dens invaginatus, endodontic surgery, maxillary lateral incisor, non-surgical root canal treatment, operative microscope