A total of 80 implants were placed in the posterior region of the maxilla in 40 patients in a split-mouth design. Bone quality was classified into type I, II, III, IV, or V as assessed preoperatively on cone-beam computed tomography (CBCT) . Primary implant stability was measured with insertion torque and resonance frequency analysis (ISQ values). Secondary stability was measured by ISQ at abutment installation.

Inclusion Criteria:

• (a) Bilateral edentulism in the maxillary posterior region dating back more than 6 months,
• (b) sufficient bone height (distance between the bone crest and maxillary sinus >8 mm) and width at the alveolar crest (≥6 mm) that would not necessitate bone augmentation,
• (c) at least 2 mm vestibular keratinized mucosa width and 3 mm mucosa thickness,
• (d) full-mouth plaque and bleeding scores <20%.

Exclusion Criteria:

• patients with systemic diseases, conditions, or used medications having the potential to impair surgery, bone, and wound healing dynamics (such as diabetes) will be excluded.
• patients who are allergic to antibiotics and non-steroidal anti-inflammatory drugs
• bone height <8mm
• ridge and soft tissue deficiencies requiring augmentation procedures and
• endodontic or periodontal lesions neighboring the edentulous sites will be also excluded.