Aim
This prospective clinical protocol aimed to assess the four-year survival and success rates of single implant-supported monolithic zirconia crowns, fabricated through a fully digital workflow, in the prosthetic rehabilitation of patients presenting with unilateral or bilateral congenital absence of the maxillary lateral incisors. The study also analyzed biological and technical variables affecting clinical outcomes, including patient-reported satisfaction.

Methods
A total of 22 patients with mono- or bilateral agenesis of the maxillary lateral incisors were enrolled, receiving 30 narrow-diameter implants. Corresponding screw-retained monolithic cubiczirconia (5Y-TZP) crowns with internal connections were digitally manufactured and delivered. Clinical performance was objectively evaluated using the Functional Implant Prosthodontic Score (FIPS), while subjective patient satisfaction was measured using a Visual Analog Scale (VAS). Survival and success analyses were performed using descriptive statistics and the Kaplan–Meier method.

Results
At the four-year follow-up, the mean FIPS (Functional Implant Prosthodontic Score) was 9.2, and the mean VAS (Visual Analog Scale) score for patient satisfaction was 8.7. Cumulative survival and success rates were 100% and 93.3%, respectively, according to Kaplan–Meier estimates.

Conclusion
The use of a fully digital implant–prosthetic protocol represents a reliable and effective short-term solution for the functional and esthetic rehabilitation of maxillary lateral incisor agenesis. Nonetheless, further longitudinal studies are warranted to confirm the long-term predictability of this approach.