ABSTRACT Objective This study evaluated the 5‐year survival of bone‐level, internal connection, sandblasted and acid‐etched (SA) implants and identified site‐ and patient‐related risk factors for implant failure in a multicenter cohort. Materials and Methods A total of 3555 tapered bone‐level SA implants were placed between 2012 and 2018 at two university dental hospitals. The observation period spanned from placement to removal or the last follow‐up (final date: May 15, 2025). Survival outcomes were analyzed using Kaplan–Meier estimates and Cox regression with shared frailty terms to adjust for clustering within patients. Results The 5‐year cumulative survival rate was 98.8% at the implant level and 99.0% at the patient level. Tooth loss due to periodontitis significantly increased implant failure risk (adjusted HR 3.57, 95% CI: 1.49–8.54, p < 0.01). Implants placed without guided bone regeneration (GBR) had a lower risk of failure than those with GBR (adjusted HR 0.42, 95% CI: 0.18–0.96, p = 0.04). Supportive periodontal therapy (SPT) compliance also influenced outcomes (adjusted HR 2.35, 95% CI: 1.32–4.18, p < 0.01). Stratified analysis showed a marked survival benefit of regular SPT among patients with periodontitis‐related tooth loss (98.8% vs. 96.3%, p = 0.004). Conclusion Bone‐level internal connection SA implants demonstrated favorable long‐term survival. However, periodontitis‐related tooth loss, GBR, and SPT compliance significantly affected implant longevity, emphasizing individualized risk assessment and continuous maintenance care. The absence of longitudinal radiographic bone‐level data limits further evaluation of peri‐implant bone stability.
Lee et al. (Sun,) studied this question.