Skip to content

Mandibular Implant Overdenture With OT Cap Bar vs Bar Attachment

Clinical and Radiographic Evaluation of Mandibular Implant Assisted Overdenture Between Bar Attachment and Bar With OT Cap Attachment: Randomized Control Clinical Trial

Status
Not yet recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07067190
Enrollment
22
Registered
2025-07-16
Start date
2026-09-01
Completion date
2027-03-01
Last updated
2026-03-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Edentulous Mandible, Implant-Supported Overdentures

Keywords

Bar Attachment, OT Cap Attachment, Implant-Assisted Overdenture, Dental Implants, Mandibular Denture Retention, Crestal Bone Loss, Patient Satisfaction, Attachment Wear

Brief summary

This clinical study is being conducted at Cairo University to evaluate two different types of attachments used with implant-supported dentures in the mandible. Patients who have lost all their teeth in the lower jaw receive implants to help hold their dentures in place. This study compares two types of attachments for connecting the denture to the implants: 1. Bar attachment only, which is a traditional method. 2. Bar with OT Cap attachment, which is a newer design that includes a small sphere (cap) to help with retention and comfort. The purpose of this study is to find out which attachment type works better in terms of: 1. How well the denture stays in place (retention) 2. How much bone is lost around the implants over time (crestal bone loss) 3. How much the attachment parts wear out (cap wear) 4. How satisfied the patients are with their dentures The study is a randomized controlled trial. This means participants will be randomly assigned to one of the two groups (bar-only or bar with OT Cap). All participants will receive complete dentures and three dental implants in the lower jaw. Follow-up will include measurements of denture retention and cap wear at the time the denture is inserted and again after 6 months. Bone loss will be checked with digital X-rays, and patient satisfaction will be assessed using a short questionnaire. The study will include 22 participants (11 in each group), aged 30 to 65, who are healthy and have enough bone in the jaw to support implants. This study is designed to help dentists and patients make better decisions about which type of implant attachment provides better long-term results and patient comfort.

Detailed description

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.

Interventions

DEVICEConventional Bar Attachment

A rigid cast bar attachment fabricated and screwed onto three mandibular implants (placed at the midline and canine areas). The bar connects the implants to provide splinting and retention for a mandibular overdenture without the use of additional retentive components such as OT Caps. The overdenture is adjusted to fit passively over the bar and picked up intraorally.

DEVICEBar with OT Cap Attachment

A cast bar attachment fitted with two OT Cap attachments, which are designed to improve prosthesis retention and load distribution. This bar system is installed on three mandibular implants (midline and canine regions). The mandibular overdenture is relined to incorporate the female retentive caps that snap onto the OT Caps. This system combines the splinting benefits of the bar with the resilient retention of stud attachments.

Sponsors

Maisa Mohamed Farid Shaaban
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)

Masking description

Only the outcomes assessor (statistician) will be blinded to group allocation to reduce assessment bias. Neither the participant nor the care provider can be blinded due to the visible nature of the intervention.

Intervention model description

Two-arm randomized controlled clinical trial comparing bar-only attachment vs. bar with OT Cap attachment in mandibular implant-supported overdentures.

Eligibility

Sex/Gender
ALL
Age
30 Years to 65 Years
Healthy volunteers
Yes

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

Design outcomes

Primary

MeasureTime frameDescription
Retention of Mandibular Implant-Supported OverdentureBaseline (T0) and 6 months after overdenture insertion (T6)Retention will be measured using a digital force gauge that applies a vertical dislodging force to the mandibular overdenture. The force required to dislodge the denture from the attachments will be recorded in Newtons. Measurements will be performed at two time points: at the time of prosthesis insertion (T0) and six months post-insertion (T6). The retention values will be used to compare the effectiveness of bar-only versus bar with OT Cap attachment systems.

Secondary

MeasureTime frameDescription
Crestal Bone Loss Around ImplantsBaseline (T0) and 6 months after overdenture insertion (T6)Crestal bone levels will be assessed using standardized digital radiographs with the Digora long-cone parallel technique. Measurements will be taken from the implant shoulder to the first bone-to-implant contact point on mesial and distal surfaces. The difference in bone height between baseline (T0) and six months (T6) will be calculated in millimeters to determine bone loss.
Attachment Cap WearBaseline (T0) and 6 months after overdenture insertion (T6)Cap wear will be evaluated by measuring the internal diameter changes of the OT Cap components using scanning electron microscopy (SEM). Measurements will be taken at baseline (T0) and after 6 months (T6) to assess material degradation and fit deterioration.
Patient Satisfaction with Overdenture6 months after overdenture insertion (T6)Patient satisfaction will be assessed using a validated Visual Analog Scale (VAS) questionnaire that evaluates comfort, stability, appearance, chewing ability, speech, ease of cleaning, and overall satisfaction. Each parameter is rated from 0 (not satisfied at all) to 100 (completely satisfied). The results will be used to compare the perceived outcomes between the two intervention groups.

Countries

Egypt

Contacts

CONTACTMaisa MF Shaaban Gomaa, PhD Candidate
maisa.gomaa@dentistry.cu.edu.eg+201002730928
CONTACTMaisa Farid
maisafarid2013@gmail.com
PRINCIPAL_INVESTIGATORMaisa MF Shaaban Gomaa, PhD candidate

Faculty of Oral and Dental Medicine, Cairo University

STUDY_CHAIRHamdy Abo El-Fotouh, Professor

Faculty of Oral and Dental Medicine, Cairo University

STUDY_DIRECTORNoha Ali, Assistant Professor

Faculty of Oral and Dental Medicine, Cairo University

STUDY_DIRECTORAhmed Hamed, Lecturer

Faculty of Oral and Dental Medicine, Cairo University

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 19, 2026