Supportive Periodontal Therapy Improves Implant Survival in Patients With a History of Periodontitis: A Retrospective Multicenter Cohort Study of 3555 Implants.

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.