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

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.

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.

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).

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.