compare CAD/CAM implant supported screw-retained metal frameworks based on actual versus screw-mented ones based on virtual implant position regarding marginal bone changes.

patients with at least three missing teeth will be recruited and randomly assigned into two parallel groups. both groups will receive three implants based on planned implant positions and then one group will receive screw retained CAD CAM restoration with conventional impression technique while the second group will receive screw-mented CAD CAM restoration based on planned implant positions.

Inclusion Criteria:

• Kennedy class I, II Or IV cases.
• Opposing completely dentulous, fully or partially restored dentition.
• Good oral hygiene.
• The patient should have bone for implants, minimum bone height 10 mm and minimum bone diameter should be 6 mm.
• Adequate inter arch space for restoration 15mm or more.
• Adult patients age ≥18 years

Exclusion Criteria:

• any medical disorder that could complicate surgical phase or affect osteointegration. Radiation chemotherapy.
• smokers more than 10/daily.
• Uncooperative patients.
• Patients with Para-functional habits
• Patients with severe periodontal diseases.
• Patients with limited mouth opening.
• Presence of intraoral pathological lesions.
• Diabetic (HbA1c >7.5%).