Mandibular Implant Overdenture With OT Cap Bar vs Bar Attachment

This randomized controlled clinical trial is designed to evaluate and compare the clinical and radiographic outcomes of two mandibular implant-supported overdenture attachment systems: (1) conventional bar attachment, and (2) bar with OT Cap (sphere) attachment. The objective is to determine which system provides superior performance in terms of prosthesis retention, crestal bone preservation, attachment wear, and patient satisfaction.

A total of 22 completely edentulous participants, aged between 30 and 65 years and meeting strict inclusion criteria, will be enrolled. Each participant will receive three endosseous implants placed in the anterior mandibular region (midline and canine positions). Following a four-month osseointegration period, participants will be randomly allocated (1:1) to one of two intervention groups: Group A (bar attachment only) and Group B (bar with OT Cap sphere attachments).

The prosthetic protocol involves the fabrication and delivery of maxillary and mandibular complete dentures, followed by intraoral placement and pick-up of the attachment systems. The primary outcome is denture retention, assessed at baseline (T0) and after 6 months (T6) using a digital force gauge. Secondary outcomes include crestal bone loss (evaluated via standardized digital radiographs), cap wear (measured using electron microscopy), and patient satisfaction (assessed using a validated Visual Analog Scale questionnaire).

Randomization will be conducted using a computer-generated sequence with allocation concealment ensured via opaque sealed envelopes. Due to the nature of the intervention, blinding of participants and clinicians is not feasible; however, outcome assessment and statistical analysis will be performed by a blinded examiner.

This study addresses a critical gap in the comparative assessment of attachment systems for implant-retained mandibular overdentures. While bar attachments are widely used for their rigidity and implant splinting capacity, recent innovations such as the OT Cap aim to enhance retention and reduce maintenance through added resilience. By directly comparing these two configurations in a controlled setting, the study aims to contribute clinically relevant data to guide prosthodontic treatment planning for edentulous patients.

Inclusion criteria

• Completely edentulous healthy patients
• Age between 30 and 65 years
• Adequate bone volume in the anterior and premolar-molar region (minimum 11 mm)
• Adequate inter-arch space (12-14 mm)

Exclusion criteria

• Severe maxillomandibular skeletal discrepancy
• Parafunctional habits (e.g., clenching, bruxism)
• Temporomandibular joint disorders
• Heavy smokers (≥20 cigarettes/day)
• History of head and neck radiation
• History of chemotherapy
• Systemic conditions that may interfere with healing or bone quality (e.g., uncontrolled diabetes, osteoporosis, bisphosphonate therapy)
• Drug abuse or alcohol dependence