A prospective randomized controlled trial of the two-window technique without membrane versus the solo-window...

Maturation of the grafted volume after lateral sinus elevation is crucial for the long-term survival of dental implants.

To compare endo-sinus histomorphometric bone formation between the solo- and two-window maxillary sinus augmentation techniques with or without membrane coverage for the rehabilitation of multiple missing posterior teeth.

Patients with severely atrophic posterior maxillae were randomized to receive lateral sinus floor elevation via the solo-window technique with membrane coverage (Control Group) or the two-window technique without coverage (Test Group). Six months after surgery, bone core specimens harvested from the lateral aspect were histomorphometrically analyzed.

Ten patients in each group underwent 21 maxillary sinus augmentations. Histomorphometric analysis revealed mean newly formed bone values of 26.08 ± 16.23% and 27.14 ± 18.11%, mean connective tissue values of 59.34 ± 12.42% and 50.03 ± 17.13%, and mean residual graft material values of 14.6 ± 14.56% and 22.78 ± 10.83% in the Test and Control Groups, respectively, with no significant differences.

The two-window technique obtained comparative maturation of the grafted volume even without membrane coverage, and is a viable alternative for the rehabilitation of severely atrophic posterior maxillae with multiple missing posterior teeth.