This clinical study aims to evaluate the effect of using PEKK (Pekkton) framework in mandibular implant-supported complete fixed dental prostheses with All-on-four treatment concept on peri-implant tissues health

The aim of this clinical study is to evaluate the effect of using PEKK (Pekkton) framework in mandibular implant-supported complete fixed dental prostheses with All-on-four treatment concept on peri-implant tissues health regarding the following parameters:

• Modified Plaque index
• Modified Gingival index
• Peri-implant probing pocket depth

Radiographic evaluation (periapical x-ray):

Marginal bone height changes

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.