(PEKK) Framework for Mandibular Implant-supported Complete Fixed Prostheses

Inclusion Criteria: * Maxillary and mandibular alveolar ridges were covered with healthy, firm, relatively even thickness and even compressible mucosa and free from any signs of inflammation or flabbiness. * Patients had completely edentulous maxillary and mandibular ridges with sufficient mandibular bone height not less than 15 mm in the interforaminal area and at least 12mm posteriorly * All patients had sufficient inter-arch space * All patients complained of insufficient retention and stability of their conventional mandibular dentures. * All patients were of Angel's class I maxillo-mandibular relationship. Exclusion Criteria: * Patients with absolute contraindications for implant placement, such as active cancer and diseases of the immune system. * Patients with metabolic diseases that are directly related to bone resorption, such as uncontrolled diabetes, osteoporosis, and hyperparathyroidism. * Patients with general contraindications for surgical procedures, such as hematologic diseases, hepatic patients, patients with bleeding disorders, and serious problems with coagulation. * Patients with a history of irradiation of the head and neck region or chemotherapy in the last 3 years were also excluded. * Patients with relative contraindications such as a history of parafunctional habits (such as bruxism and clenching), smoking, alcoholism, and patients with any physical reasons that could affect follow-up. * Patients with local contraindications for implant placement, such as localized bone defects.