Comparative Evaluation Between One-piece and Two-piece Implants Supporting Mandibular Screw-retained All-On-Four Full-arch Prosthesis on Peri-implant Bone Changes.

Studying the difference between one-piece and two-piece implants and their effect on bone loss. This will help in simplifying the surgical procedure for full arch implant-supported prosthesis rehabilitation using one-piece implants, eliminating the disturbance of the gum tissue around the implants, potentially reducing the risk of bacterial colonization and inflammation.

Inclusion criteria

• Completely edentulous patients, who can sign an informed consent will be considered eligible for this trial.
• Residual bone height should have sufficient volume and quality for implant placement with a minimum of 12-14 mm in height and 6 mm in width.
• Patients who already have existing maxillary and mandibular complete dentures, and after examination of the mandibular dentures, technical problems concerning denture design and/or occlusion are found, or who are dissatisfied with the retention and stability of their technically satisfactory mandibular dentures.

Exclusion criteria

• - Patients with conditions that may contraindicate implant placement (e.g., Immunosuppressed or immunocompromised patients, patients under treatment of intravenous amino bisphosphonates, patients undergoing radiotherapy to the head and neck region).
• Inadequate mouth opening
• Heavy smokers, more than 10 cigarettes/day
• Patients with poor oral hygiene and motivation.
• Pregnancy or nursing.
• Drug abusers.
• Psychiatric problems or unrealistic expectations.
• Patients with infection and or inflammation in the area intended for implant placement.