Abstract
The congenitally missing maxillary lateral incisor is the most common agenesis in the anterior region. There are several treatment options for this anomaly, which causes severe deficiencies: orthodontic space closure, tooth-supported restoration, or single-tooth implant. Each of these solutions has a high degree of success if used in the correct situation. An implant-supported restoration with an interdisciplinary approach provides a predictable outcome. This article describes the treatment of a patient with agenesis of the maxillary left lateral incisor. After orthodontic space management, it was decided to restore the tooth with an all-ceramic crown cemented on a zirconia custom abutment, which fractured after only 6 weeks of service. Fractographic analysis revealed that the failure was due to over-reduction of the buccal wall to correct the labial emergence of the implant. Zirconia abutments should be designed with even wall thicknesses of at least 0.8 mm to avoid areas that may compromise functional success.