The retention of a complete implant overdenture prosthesis is defined as the minimum retention force (N) required to separate the male part of the attachment from the female part. The retention strength will be measured 3 times with a force gauge that allows the application of the retention force perpendicular to the occlusal plane of the prosthesis and parallel to the long axis of the implant, and the values will be averaged with a digital dynamometer. As the measurement value increases, it is concluded that the retention of the prosthesis increases. The measurements will be recorded on the 'Patient Measurement Card' at each control session.

The retention of the implanted complete denture will be measured at the time of delivery of the implant overdenture to the patient and at the control sessions 1 week, 1 month, 3 months, and 6 months after the patient start to use the denture.

Patients' overall satisfaction, comfort, speech ability, prosthesis stability, retention, aesthetics, and ease of cleaning will be assessed using VAS measurements. The rating words will be 'very satisfied' and 'not at all satisfied,' and patients will be asked to draw a vertical line on a 10 cm horizontal line at the point that best represents their perception. The VAS total score is between 0-10. As the score increases, it is concluded that the patient's satisfaction increases. Patients will be asked to fill out the VAS questionnaire form during the 1st month (TI) after using the prosthesis and at 3 months and 6 months of control sessions.