Purpose: The purpose of this systematic review was to assess the survival of implants placed in augmented sinuses on a medium- to long-term basis, and identify factors affecting implant survival such as surgical technique, bone grafts, and timing of implant placement.
Materials and methods: A literature search up to July 2016 was performed to identify prospective clinical studies on sinus floor augmentation in conjunction with implant placement with a minimum follow-up of 3 years. Meta-analytic methods were implemented to calculate implant survival rates and relative risks (RR) for failure and the effect of surgical technique, use of bone graft, graft type, use of membrane, mean residual bone height, and timing of implant insertion.
Results: A total of 17 clinical trials (1 randomized and 16 prospective nonrandomized) were included, which pertained to 637 patients (at least 48% male) and 1,610 implants placed after sinus floor augmentation with the osteotome (transalveolar) or lateral window approach. The pooled implant survival rate at 3 to 6 years of follow-up was 97.7% (17 studies; 95% CI = 94.4% to 99.7%) with high heterogeneity. Smoking was associated with significantly worse implant survival (2 studies; RR = 4.8; 95% CI = 1.2 to 19.4; P < .05). However, evidence of influencing factors varied from very low to moderate after adopting the GRADE approach, due to risk of bias, imprecision, inconsistency, and small-study effects.
Conclusion: Current evidence suggests that implants in augmented sinuses have high survival rates, with smoking playing a potentially important negative role in their prognosis. Both indirect and direct maxillary sinus floor augmentation seem to have a low frequency of manageable complications.