Purpose: To assess the clinical and radiographic outcomes of computer-aided designed and manufactured (CAD-CAM) zirconia bars supporting mandibular implant-retained overdentures (IODs) after a 3-year follow-up.

Methods: A prospective observational single-center study involving 30 edentulous patients rehabilitated with two mandibular implants and a mandibular implant overdenture supported by a computer-aided design - computer-assisted manufacturing zirconia bar with distal extensions was performed assessing clinical and radiographic parameters.

Inclusion Criteria:

• Edentulous individuals for more than one year.
• Individuals with sufficient anatomical bone conditions in the interforaminal area to place implants of 4.3mm in diameter and at least 10.0mm in length without bone augmentation needs.
• Written consent to participate and to attend the study and the yearly follow-ups.

Exclusion Criteria:

• Individuals suffered from psychiatric problems.
• History of cerebrovascular or cardiovascular accident within the last six months.
• Uncontrolled or insulin-dependent diabetes, immuno-compromised status, current chemotherapy, and leukocyte system diseases.
• Severe systemic health conditions do not allow surgical intervention with local anesthesia.
• Irradiated bone.
• Severe parafunctional habits
• Drugs or alcohol abuse.
• Insufficient oral hygiene.
• Unrealistic treatment demands.
• Smokers were not excluded, but a cessation protocol was suggested before the implant treatment.
• Unwillingness to participate in the study.