The purpose of this study is to present a guided lateral window sinus lift (GLSL) procedure with the aid of a fully digital workflow using surgical templates for window osteotomy preparation and implant placement.

In Group 1; The surgical procedure began with the adaptation of a prefabricated guide to the surgical site, ensuring firm stabilization. Implant positions were marked, and after the removal of the guide, a crestal incision was made. A mucoperiosteal flap was reflected, exposing the maxillary sinus and alveolar crest. The guide was readapted, marking implant positions, and a lateral window was formed using a bur or piezotome. Sinus membrane elevation was performed carefully. Implants were placed with graft material beneath the elevated membrane. In cases of bony plate preservation, the window was covered. In Group 2 (Lateral Maxillary Sinus Floor Elevation without a surgical guide), a crestal incision and mucoperiosteal flap exposed the sinus. A bony window was created, and careful elevation of the sinus floor followed. Implant osteotomies were completed, and graft material was packed into the sinus. A resorbable membrane was applied, and the flap was sutured. NanoboneÒ was used as the standard graft material in both groups.

Inclusion Criteria:

• Healthy adult patients (over 18 years of age), without any systemic complication.
• Patients who need for dental implant in posterior maxilla with bone height below the maxillary sinus is < 6 mm.
• Non smokers or patients who smoked less than 11 cig/day Will be included.

Exclusion Criteria:

• Uncontrolled systemic diseases which affect bone healing.
• Presence of any pathology in the site of operation.