Real-World Implant Survival in the Esthetic Zone: Uncovering Timing-Specific Risk Patterns in a Large Cohort.

OBJECTIVES: Implant survival in the esthetic zone is often reported as an overall outcome, although factors associated with failure may vary across different phases of treatment. This study evaluated real-world implant survival in the anterior maxilla and examined whether risk patterns differ between early and late failure phases. MATERIALS AND METHODS: This retrospective study used electronic health record data from a nationwide dental network. A total of 14,079 implants placed in 8234 patients between 2014 and 2023 were analyzed. Implant failure was defined as removal or spontaneous exfoliation. Survival was assessed using Kaplan-Meier analysis and Cox proportional hazards models with patient-level clustering. A 6-month timing-specific approach distinguished early from late failures, with restoration modeled as a time-varying covariate. RESULTS: During a mean follow-up of 6.0 ± 2.9 years, 358 implants failed, yielding a failure rate of 2.5% and an incidence rate of 0.43 failures per 100 implant-years. Early failures accounted for 43.6% of failures. Short implant length (≤ 8 mm) was associated with failure across all phases, based on a small subgroup (54 implants; overall HR 5.15, 95% CI 2.40-11.02; p < 0.001). Immediate restoration was associated with early failure (HR 1.91, 95% CI 1.28-2.85; p = 0.002). Smoking was associated with late failure (HR 1.81, 95% CI 1.29-2.54; p = 0.001). CONCLUSIONS: Implant survival in the anterior maxilla was high, but failure risk differed by phase. Short implants (≤ 8 mm) were associated with failure across all phases, while immediate restoration was associated with early failure and smoking with late failure.