The surgical intervention will be executed under local anesthesia. After the elevation of the full-thickness mucoperiosteal flap over the lateral wall of the maxillary sinus, a circular lateral window will be created by sinus low-speed bur grinding of the cortical ring to guard against the Shniederian membrane violation, followed by its separation along the sinus floor, lateral walls and the boundaries of the window to elaborate a smooth superior membrane elevation.

The created spaces beneath the elevated Shniederian membrane will be filled up by an absorbable gelatin sponge for the test group patients followed by the coverage of the side window with collagen membrane, secured with bone tacks to guard against the graft fibroblastic invasion.

The surgical intervention will be executed under local anesthesia. After the elevation of the full-thickness mucoperiosteal flap over the lateral wall of the maxillary sinus, a circular lateral window will be created by sinus low-speed bur grinding of the cortical ring to guard against the Shniederian membrane violation, followed by its separation along the sinus floor, lateral walls and the boundaries of the window to elaborate a smooth superior membrane elevation.

The created spaces beneath the elevated Shniederian membrane will be filled up by allogenic (DBM) for the control group patients, followed by the coverage of the side window with collagen membrane, secured with bone tacks to guard against the graft fibroblastic invasion.

The implant osteotomy will be initiated by pilot drill entries followed by sequential drills via the radiographic stent's sleeves to position the fixtures precisely into the pre-determined recipient sites. The Implant stability quotient (ISQ) will then be measured using an Osstell device after attaching intelligent implant pigs. Finally, the mucoperiosteal flaps will be sutured in place with 4-0 Prolene.

baseline and final outcome for measuring both groups' radiographic vertical bone height gain as a primary outcome aided by the (Blue-sky software) identification of four reference points along each implant buccal, palatal, mesial, and distal surface

Aided by the Osstell device, the authors will record the (ISQ) readings at implant placement and upon its exposure for prosthetic rehabilitation after six months as a secondary outcome. The mean (ISQ) of the maxillary sinus lift procedure would employ the mean of parallel and perpendicular (ISQ) readings to each implant long axis where one implant is inserted and the mean of the two implant readings when two implants are placed.

The numerical data concerning the primary and secondary outcomes will be recorded, scheduled, and submitted for statistical analysis