This clinical study will evaluate two types of attachment systems used to support lower dentures in patients who have lost all their lower teeth. All participants will receive dental implants in the lower jaw, and a complete denture that attaches to these implants for better stability and comfort.

The study compares two options:

A traditional bar attachment

A bar with additional OT Equator attachments, which are designed to improve denture retention and reduce wear

Each participant will receive three implants in the lower jaw, and either a bar attachment alone or a bar with OT Equator attachments will be placed. The goal is to find out which method provides better retention of the denture, causes less bone loss around the implants, has less wear on the attachment parts, and leads to higher patient satisfaction.

Participants will be followed over several months. Their denture retention will be tested using a digital force meter, bone levels will be measured through radiographs, cap wear will be examined using an electron microscope, and satisfaction will be recorded using a questionnaire.

This study is being conducted at Cairo University and is self-funded by the primary investigator. Participation is voluntary and does not involve any financial cost to participants.

This randomized controlled clinical trial aims to compare the clinical and radiographic outcomes of mandibular implant-supported overdentures using two different attachment systems: bar attachment alone (control group) versus bar with OT Equator attachments (intervention group).

A total of 22 completely edentulous participants will be randomly assigned to either group. Each participant will receive three dental implants placed in the anterior mandible. After healing, bar attachments will be fabricated and delivered. In the intervention group, OT Equator attachments will be added to the bar to enhance retention and flexibility. All participants will receive complete upper and lower dentures.

The study's primary outcome is denture retention, measured using a digital force gauge. Secondary outcomes include crestal bone loss (assessed radiographically), cap wear (measured via electron microscopy), and patient satisfaction (evaluated with a Visual Analog Scale questionnaire).

This study will help inform clinical decisions regarding attachment systems for mandibular overdentures and may provide evidence for improved long-term function and patient-reported outcomes.

Inclusion Criteria:

• Completely edentulous healthy patients.
• Age between 35 and 65 years.
• Sufficient bone in the anterior and premolar-molar regions (≥11 mm).
• Adequate inter-arch space (12-14 mm).

Exclusion Criteria:

• Severe maxillomandibular skeletal discrepancy.
• Presence of parafunctional habits such as clenching or bruxism.
• Temporomandibular joint disorders.
• Smokers.
• History of drug abuse.
• History of head and neck radiation.
• Systemic disorders that could prevent surgery or affect bone quality (e.g., uncontrolled diabetes, osteoporosis).

Individual participant data (IPD) will not be shared to protect participant confidentiality and because no formal mechanisms are in place for data sharing beyond the study team. Data will remain securely stored at Cairo University and accessible only to the authorized research team.

Only the outcome assessor (statistician) is blinded to the group allocation. Due to the nature of the interventions, participants and investigators cannot be blinded.