Immediate Fixed Implant Rehabilitation of the Atrophic Edentulous Maxilla after Bilateral Sinus Floor Augmentation: A 12-Month Pilot Study

Purposes: The aims of this study were to evaluate a surgical/prosthetic protocol for the immediate rehabilitation of the augmented edentulous maxilla, and to compare the outcomes of implants placed in grafted (test group) versus native (control group) sites in the same patients. Materials and Methods: Twenty patients were included in the study. Each patient was treated with a bilateral sinus augmentation procedure using a 50:50 composite graft of autogenous mandibular bone and bovine hydroxyapatite. Four to 5 months later, 155 implants (90 test and 65 control) were placed and restored with screw-retained fixed definitive prostheses supported by titanium frameworks within 1 week. All patients were followed for 1 year. Implant stability quotient (ISQ) measurements and radiographic evaluation of the marginal bone resorption (MBR) were performed. Results: Two test implants failed in two patients, giving a cumulative 1-year success rate of 98.7%; the prostheses success rate was 100%. Insertion torque and ISQ values for test implants were significantly lower than those for control implants (unpaired t-test, p < .0001). The mean MBR around control and test implants at the 1-year evaluation were similar (0.47 +/- 0.25 mm and 0.43 +/- 0.21 mm, respectively). Conclusions: The combination of implants placed in sinus-grafted and native sites can be immediately loaded with a fixed full-arch prosthesis and yield short-term successful outcomes.