Two Versus Four Implant-supported Fixed Full-arch Prosthesis

Inclusion Criteria: * • Eligible patients needed must have Sufficient interarch space (at least 15 mm from the occlusal plane to the mandibular ridge) to provide space for fixed prosthesis construction all patients should be completely edentulous patients with resorbed mandibular ridge all patients must be angle class I Exclusion Criteria: * systemic diseases that contraindicate implant placement bone metabolic diseases such as diabetes mellitus irradiation of the head and neck region chemotherapy within the past 3 years smoking habits.