Outcomes of implants placed in sites of previously failed implants: a systematic review and meta-analysis

The survival rate of implants placed at sites of previous failures including the best treatment strategies remain unclear. This systematic review was performed to assess implant survival and peri-implant health for such cases, including subgroup analyses of immediate versus delayed implant placement and augmentation. Four electronic databases were searched. Meta-analyses including subgroup analyses were performed (PROSPERO CRD42024548610). Out of 1798 records identified, 24 studies were included. The 1-year implant survival rate after replacement was 96.7% (95% confidence interval (CI) 92.8-99.3%), with no significant difference between immediate and delayed placement (P = 0.31) or immediate and delayed augmentation (P = 0.85). Immediate augmentation showed higher overall implant survival (97.6%, 95% CI 93.4-99.9%) compared to delayed augmentation (91.7%, 95% CI 83.4-97.5%), although not statistically significant (P = 0.26). Peri-implant health outcomes, including marginal bone loss, were similar across subgroups. Second implant replacements had lower survival rates than first replacements. Replacement of the failed implant is an appealing treatment option for failed implants, although the implant survival is lower compared to initially placed implants. Immediate implant placement can be done if sufficient bone is present. If insufficient bone remains after removal, immediate augmentation followed by delayed implant placement is recommended.