Evaluation of Bone Changes Around Implants in Patients Treated With All on Four

All patients will receive upper complete dentures and mandibular All on-4 screw-retained prosthesis. The upper complete denture will be mucosa supported and the lower will be All on-4 screw-retained prosthesis. Patients will be divided into two equal groups; Group I will receive two axially placed anterior implants and two distally inclined 30-degree angle posterior implants, while Group II will receive two axially placed anterior implants and two distally inclined 45-degree angle posterior implants.

Both groups will be functionally loaded after three months of insertion. Bone height changes around axial and distally inclined implants will be evaluated using cone beam CT (CBCT), All records will be taken at time of denture insertion, 6 and 12 months later.

Inclusion criteria

• All patients' ages must range from 50-65 years old.
• All patients' ridges should be covered with firm mucosa free from any signs of inflammation or ulceration and exhibit adequate height and width of the residual alveolar ridge.
• Patients should be free from any metabolic or bone disorders that contraindicate implant installation.
• All patients must have sufficient inter arch space

Exclusion criteria

• Patients with oral or systemic diseases.
• Patients with xerostomia or excessive salivation.
• Patients with parafunctional habits (bruxism or clenching).
• Heavy smoker or alcoholic patients.
• Patients with history of temporo-mandibular dysfunction.
• Patients with brain disorders or psychiatric disorders