Evaluation of three-dimensional changes after sinus floor augmentation with different grafting materials

Objective: The aim of this retrospective investigation was to assess the dimensional stability of different grafting materials after maxillary sinus floor augmentation with computed tomography (CT) scans. Materials and methods: Two postoperative CT scans were available from 16 patients who had undergone maxillary sinus lift procedures. The first scan was made within a few days after the surgical intervention and the second one > 6 months later. A total of 25 maxillary sinuses were augmented with different materials before implant insertion by lateral antrostomy in a staged approach. The volume of bone formation was calculated using the Somaris (R) Sienet Magic View software. Results: Based on volumetric measurements of the augmented domes derived from the image sections, shrinkage was about 26%. The mean of the augmented bone volume was 3.02 cm(3) (1.4-5.56 cm(3); SD +/- 1.18 cm(3)) as determined in the first CT scan. The respective mean volume in the second CT scan amounted to 2.28 cm(3) (0.92-4.46 cm(3); SD +/- 1.07 cm(3)). Conclusion: Within the limits of our descriptive and analytic study, the results indicate a significant reduction of the graft volume after maxillary sinus augmentation. Further prospective studies will have to evaluate the quantitative changes of different bone graft materials for maxillary sinus augmentation procedures in order to improve long-term implant stability.