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Completed

NCT Number: NCT07536776

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

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.

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Key information

Conditions

Marginal Bone Loss Around Implants

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Basma

Al Mansurah, Egypt

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

implant retained overdenture

Other

4 implants retained prosthesis by locators

four dental implant with locator attachment

Device

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.

Primary outcomes

  1. 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.

Secondary outcomes

  1. 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.

Sponsors and collaborators

Lead sponsor

Mansoura University

Other

Registry information

Official study title

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

Important dates

Study start
2018
Primary completion
2026
Study completion
2026
First posted
Apr 17, 2026
Registry last updated
Aug 13, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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