Mandibular Implant Overdenture With Bar vs OT Equator: A Randomized Controlled Trial

Clinical And Radiographic Evaluation of Mandibular Implant Assisted Overdenture Between Bar Attachment and Bar With OT Equator Attachment: Randomized Controlled Trial

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Edentulous Mandible; Implant-Supported Overdentures
• Intervention / Treatment: Device: Bar Attachment; Device: Bar with OT Equator Attachment

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 22
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Hala MF Selim, PhD Candidate; Phone Number: +201140733119; Email: hala.selim@dentistry.cu.edu.eg

Study Locations

• Egypt
  • Cairo Governorate
    • Cairo, Cairo Governorate, Egypt, 11553
      • faculty of oral and dental medicine, Cairo university
      • Contact: Hala MF Selim, PhD Candidate; Phone Number: 01140733119; Email: hala.selim@dentistry.cu.edu.eg

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

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).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Bar Attachment Only; Participants in this group will receive a mandibular implant-assisted overdenture supported by a milled bar attachment only. Three implants will be placed in the anterior mandible (midline and canine regions), and a bar attachment will be fabricated without any additional retentive elements.	Device: Bar Attachment; A bar attachment supported by three mandibular implants (placed in the midline and canine regions) is used to retain a mandibular overdenture. The bar provides rigid splinting across the implants and allows retention using friction or clips, without additional attachment components. This serves as the control group.
Experimental: Bar with OT Equator Attachment; Participants in this group will receive a mandibular implant-assisted overdenture supported by a milled bar with OT Equator attachments. Three implants will be placed in the anterior mandible (midline and canine regions). Two OT Equator attachments will be incorporated into the bar to enhance retention and stress distribution.	Device: Bar with OT Equator Attachment; A bar attachment supported by three mandibular implants is combined with two OT Equator attachments to enhance denture retention and allow slight vertical and rotational resilience. The OT Equator system includes metal housings and retentive nylon caps, intended to reduce cap wear and improve patient comfort. This is the experimental arm.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Retention of Mandibular Overdenture	Retention will be measured using a digital force gauge. A standardized technique will be used to measure the force required to dislodge the mandibular overdenture by pulling upward from a geometric center marked on the denture.	At baseline (T0) and 6 months post-insertion (T6)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Crestal Bone Loss Around Implants	Bone level changes will be assessed radiographically using the long cone parallel technique. Crestal bone height will be measured on standardized radiographs at two time points and recorded in millimeters.	At baseline (T0) and 6 months post-insertion (T6)
Cap Wear of Attachment System	Cap wear will be evaluated by measuring physical changes in the nylon caps of the attachments using an electron microscope. Measurements will be taken in millimeters to assess material degradation.	At baseline (T0) and 6 months post-insertion (T6)
Patient Satisfaction	Patients will complete a Visual Analog Scale (VAS) questionnaire assessing overall satisfaction, comfort, speech, chewing ability, aesthetics, and ease of cleaning with the overdenture.	At 6 months post-insertion (T6)

Collaborators and Investigators

• Sponsor: Hala Abdel salam Selim
• Investigators: Study Chair: Hamdy Abo El-Fotouh, Professor, faculty of oral and dental medicine, Cairo university; Study Director: Ahmed Hamed, Lecturer, faculty of oral and dental medicine, Cairo university; Study Director: Noha Ali, asso. Professor, faculty of oral and dental medicine, Cairo university

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2025
• Primary Completion (Estimated): March 1, 2026
• Study Completion (Estimated): March 1, 2026

Study Registration Dates

• First Submitted: August 7, 2025
• First Submitted That Met QC Criteria: August 7, 2025
• First Posted (Actual): August 14, 2025

Study Record Updates

• Last Update Posted (Actual): August 14, 2025
• Last Update Submitted That Met QC Criteria: August 7, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: Patient satisfaction; Crestal bone loss; OT Equator attachment; Denture retention; Bar attachment; cap wear
• Additional Relevant MeSH Terms: Mouth Diseases; Stomatognathic Diseases; Tooth Diseases; Mouth, Edentulous
• Other Study ID Numbers: HS-OTBarRCT2024

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: 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.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No