Radiographic and Retention Evaluation Over Seven Years for Four Implant Retained Overdenture

August 11, 2026 updated by: Mansoura University

Marginal Bone Loss and Retention of Four-Implant Locator-Retained Mandibular Overdentures: 7 Years Follow up

ABSTRACT Statement of the problem: Insufficient long-term retrospective data is evaluating marginal bone loss and retention of four-implant Locator-retained mandibular overdentures.

Purpose: To assess marginal bone loss and retention of four-implant Locator-retained mandibular overdentures over seven years at the time of overdenture insertion (T0), 1 year (T1), and 7 years (T7) after insertion.

Material and methods: This retrospective study included 27 completely edentulous patients with maxillary single denture, and four parallel implants were placed interforaminal, and they already have a mandibular four-implant retained overdenture with LOCATOR attachments.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

27

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Egypt
      • Al Mansurah, Egypt
        • Basma

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria Patients rehabilitated with a mandibular overdenture retained by four dental implants.

Four implants positioned in the anterior and premolar regions of the mandible. Four Locator attachments used to retain the mandibular overdenture. Availability of baseline clinical and radiographic records at the time of prosthesis insertion.

Availability of clinical and radiographic records at 1-year and 7-year follow-up.

Exclusion Criteria Patients with incomplete clinical or radiographic records. Patients without the required 1-year or 7-year follow-up records. Patients with radiographs that were inadequate for reliable assessment of peri-implant marginal bone levels.

Patients whose records did not allow assessment of prosthetic retention at the specified follow-up periods.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Implant-Retained Overdenture Group
Other: implant retained overdenture
4 implants retained prosthesis by locators
Device: four dental implant with locator attachment
A mandibular overdenture retained by four dental implants using Locator attachments. The implants are positioned in the anterior and premolar regions of the mandible, and the prosthesis is retained by four Locator attachments. Patients are followed clinically and radiographically over the follow-up period.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Marginal Bone Loss by periapical radiography
Time Frame: From the time of implant loading (Baseline), 1year and 7 years.
Marginal bone loss will be assessed using standardized intraoral periapical radiographs. The vertical distance from the implant reference point to the alveolar bone crest will be measured on the mesial and distal surfaces of each implant. Measurements will be recorded at implant insertion (baseline), 1 year, and 7 years, and the mean value of the four implants will be calculated for each patient.
From the time of implant loading (Baseline), 1year and 7 years.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Prosthetic Retention by a digital force gauge
Time Frame: baseline, 1year and 7 years.
Prosthetic retention will be assessed by measuring the dislodging force required to remove the mandibular overdenture using a digital force gauge. The retention force will be recorded in Newtons (N) at baseline and at 7 years after insertion.
baseline, 1year and 7 years.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Mansoura University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 12, 2018

Primary Completion (Actual)

January 15, 2026

Study Completion (Actual)

February 20, 2026

Study Registration Dates

First Submitted

April 11, 2026

First Submitted That Met QC Criteria

April 11, 2026

First Posted (Actual)

April 17, 2026

Study Record Updates

Last Update Posted (Actual)

August 13, 2026

Last Update Submitted That Met QC Criteria

August 11, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • R.26.02.105

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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