Three-dimensional Accuracy of Direct Digital Scanning for All on Four Implants in Comparison to a Custom-made Verification Jig in Fully Edentulous Patients

Inclusion Criteria: * Patients with complete mandibular edentulism. * Patients requiring full-arch rehabilitation with an All-on-4 implant concept. * Absence of systemic conditions that could affect bone healing or osseointegration. * Adequate bone volume in the anterior mandible for implant placement without the need for additional grafting. * Patients capable of maintaining oral hygiene Exclusion Criteria: * Patients with uncontrolled systemic diseases (e.g., diabetes, osteoporosis). * History of head and neck radiation therapy. * Severe parafunctional habits (e.g., bruxism). * Patients with inadequate bone volume requiring extensive grafting procedures. * Active periodontal or oral infections.