Maxillary Sinus Augmentation Using CAD/CAM Allogenic Bone Blocks Versus Particulate Allogenic Grafts

28patients will be included in this study with an atrophic posterior maxillary ridge due to sinus pneumatization, who will be randomly assigned to two groups

• Group I: sinus lifting using CAD/CAM allogenic block through lateral window technique
• Group II: sinus lifting using particulate allogenic graft through the lateral window technique
• Surgical procedure: A full-thickness, wide mucoperiosteal flap was elevated buccally. Alateral bony window of the maxillary sinus will be made then the sinus lining will be elevated carefully. The CAD/CAM allogenic block will be inserted and fixed in its position via a titanium screw to the crest of maxillary ridge (group I). In group II the particulate bone will be packed at the site of augmentation

• The lateral window will be covered with collagen membrane, the flap will reposited in its place and sutured.

  6 months later, implants will be inserted