NCT07429149

Brief Summary

This randomized clinical trial aimed to evaluate the radiographic and clinical evaluations of mandibular implant-supported overdentures supported d by two different bar materials。 Completely edentulous patients received two implants in the mandibular canine region and were rehabilitated with overdentures supported by a conventional cobalt-chromium bar and a zirconia CAD/CAM bar。 Radiographic marginal bone loss around implants, crestal bone height changes posteriorly and clinical peri-implant parameters were assessed at baseline,6 months, and 12 months to compare the performance of both bar materials。

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
12

participants targeted

Target at below P25 for not_applicable

Timeline
Completed

Started Jul 2022

Typical duration for not_applicable

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Start

First participant enrolled

July 18, 2022

Completed
2.9 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 17, 2025

Completed
2 days until next milestone

Study Completion

Last participant's last visit for all outcomes

June 19, 2025

Completed
8 months until next milestone

First Submitted

Initial submission to the registry

February 3, 2026

Completed
21 days until next milestone

First Posted

Study publicly available on registry

February 24, 2026

Completed
Last Updated

February 24, 2026

Status Verified

February 1, 2026

Enrollment Period

2.9 years

First QC Date

February 3, 2026

Last Update Submit

February 17, 2026

Conditions

Edentulous Mandible

Keywords

Mandibular Implant-Supported OverdentureCobalt-Chromium barZirconia CAD/CAM barMandibular implantsCrestal bone loss

Outcome Measures

Primary Outcomes (2)

  • Marginal bone loss around Implants

    Radiographic assessment of marginal bone loss around mandibular implants and crestal bone height changes posteriorly using cone-beam computed tomography (CBCT)

    Baseline,6 months, and 12 months

  • Posterior crestal bone height changes of the mandibular ridge

    Radiographic assessment of posterior crestal bone height changes of the mandibular ridge using cone-beam computed tomography (CBCT)

    Baseline,6months,12months

Secondary Outcomes (4)

  • Peri-Implant probing depth

    Baseline,6 months, and 12 months

  • plaque index around implants

    Baseline, 6 months, and 12 months

  • Bleeding on probing around implants

    Baseline, 6 months, and 12 months

  • Implant mobility

    Baseline, 6 months, and 12 months

Study Arms (2)

Conventional Cobalt-Chromium Bar

EXPERIMENTAL

participants received mandibular implant-supported overdentures supported by a conventional cast cobalt-chromium bar

Device: Cobalt-Chromium Bar Attachment

Zirconia CAD/CAM Bar

EXPERIMENTAL

participants received mandibular implant-supported overdentures supported by a Zirconia CAD/CAM-fabricated bar

Device: Zirconia CAD/CAM Bar Attachment

Interventions

Cobalt-Chromium Bar AttachmentDEVICE

A conventional cast cobalt-chromium bar used to retain a mandibular implant-supported overdenture

Conventional Cobalt-Chromium Bar
Zirconia CAD/CAM Bar AttachmentDEVICE

A zirconia CAD/CAM-fabricated bar used to retain a mandibular implant-supported overdenture

Zirconia CAD/CAM Bar

Eligibility Criteria

Age50 Years - 60 Years
Sexmale
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Patients age range was between 50-60 years old.
  • Only male patients were selected to participate in this study.
  • All patients were apparently free from any systemic or debilitating diseases that might affect bone metabolism or delay post-operative healing.
  • Patients were free from any temporo-mandibular joint disorders.
  • Patients were free from any neuromuscular or bony disorders, and medically free from any neurologic disorder affecting the neuro-muscular system.
  • Patients' residual alveolar ridges were covered with firm, healthy mucosa, free from any signs of inflammation, ulceration, or flabby tissue.
  • Mandibular edentulous alveolar ridge areas had sufficient width and height of alveolar bone.
  • Patients exhibited Angle Class I maxillo-mandibular relationship and sufficient inter-arch space.
  • Patients had good oral hygiene.
  • A period of at least six months up to one year had elapsed from the last extraction.

You may not qualify if:

  • Patients with systemic diseases that might affect bone quality, contribute to bone resorption, increase surgical risk, or delay/complicate post-operative healing.
  • Patients with parafunctional habits such as bruxism, clenching, or grinding.
  • Patients with residual ridge covered by inflamed, ulcerated, or flabby mucosa.
  • Patients with inadequate inter-arch space.
  • Patients with abnormal tongue behavior and/or size.
  • Patients with xerostomia or excessive salivation.
  • Heavy smoker patients and alcoholic patients.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Faculty of Dental Medicine for Girls, Al-Azhar University

Cairo, Nasr City, Egypt

Location

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR INVESTIGATOR
PI Title
Assistant Lecturer of Removable Prosthodontics

Study Record Dates

First Submitted

February 3, 2026

First Posted

February 24, 2026

Study Start

July 18, 2022

Primary Completion

June 17, 2025

Study Completion

June 19, 2025

Last Updated

February 24, 2026

Record last verified: 2026-02

Data Sharing

IPD Sharing
Will not share

Locations

EG(1)