Immediate functional loading of edentulous maxilla: A 5-year retrospective study of 388 titanium implants

Background: Immediate functional loading is a new surgical-prosthetic technique that can be used extensively in implant placement. Because of a lack of experimental reports regarding edentulous maxilla, we decided to evaluate the survival rate of immediately loaded dental implants in this area. Methods: Forty-three patients (44.4% male) with a median age of 55 years receiving 388 implants (mean 9.0 per case) were enrolled in this study. Cross-arch acrylic provisional restorations were performed in the same stage. Data were analyzed by Kaplan-Meier product limit estimation. Stratiflcation of implants survival was performed for the available variables of interest, and comparisons were analyzed by a log rank test. Cox algorithm was used for multivariable analysis. Results: At 5-year follow-up, the crude survival rate (overall survival not stratified according to any available variable) was 98%. All failures occurred within 6 months from loading. We found differences in survival relating to: 1) implant diameter (99.37% for diameter <= 5.25 mm and 93.75% for diameter > 5.25 mm); 2) number of implants (99.29% for <= 10 implants and 96.30% for > 10); and 3) gender (97.08% and 99.54 % for males and females, respectively). Cox regression analysis showed that diameter of implants adjusted for patient age and gender was associated to an average risk of failure (hazard rate) of 3.13 (P value = 0.042, 95% confldence interval 1.04 to 9.43) per mm (from 3 to 6.5). Conclusions: Immediate functional loading is a reliable surgical-prosthetic procedure in edentulous maxillae. Implants with wider diameter are associated with a higher risk of failure.