This study aims to evaluate the effect of mandibular implant supported removable overdenture on bone height and density and compare it with implant supported fixed overdenture in single mandibular overdenture.

In this study 10 patients will be selected following inclusion and exclusion criteria. In each group 5 patients (each patient will receive 6 implants) will be divided randomly into two groups.

Group I patients will receive mandibular implant supported removable overdenture, while Group II will receive mandibular implant supported fixed overdenture.

All patients will be given the usual home care instructions about wearing and caring of dentures and opposing arch. Regarding dentures, removal of them at night and cleaning with denture brush and mild soap will be required. Measurements of Bone height and Bone density will be obtained by using Cone Beam Computed Tomography (CBCT).

Measurements will be obtained at denture insertion, after 1 month and after 3 months.

Inclusion Criteria:

• Non-smoker Patients
• Highly cooperative and motivated patients.
• Patients Systemically free from any immunosuppressive diseases.

Exclusion Criteria:

• Diabetic, hypertensive, cancer patients.
• Mandibular arch with thin knife edge, flat or flabby ridge, recent extractions and foreign bodies.
• Patients with temporo-mandibular joint disorders and bad oral habits.

each patient was not informed about type of received restoration