Long-term retrospective evaluation of dental implants placed in resorbed jaws reconstructed with appositional fresh-frozen bone allografts

Introduction: The aim of this study was to evaluate the outcome of fresh-frozen bone allografts in preprosthetic surgery for implant placement purposes. Materials and Methods: The cohort comprised 45 patients treated with fresh-frozen bone block grafts and dental implants. Clinical and radiological evaluations were performed to evaluate the survival rate. The data were statistically analyzed with the Kaplan-Meier estimator to assess the influence of possible predictors of implant failure on survival. Results: Overall, 262 implants were retrospectively analyzed. The survival rate was 90.84% over a mean follow-up of 50 months. Comparing the donor site and the position of the implants, no statistically significant differences could be detected (P = 0.7194 and P = 0.2901, respectively), whereas sex resulted in a marginally statistically significant difference (P = 0.0581). When considering age categorized on the median value (≤55/>55 years), age resulted in a statistically significant difference (P = 0.0340), with higher failures found in older people. Conclusion: Implant loss was strictly related to the lack of primary osseointegration. Female sex and old age were found to be risk factors, which could negatively influence implant survival.