A Randomized Controlled Clinical Trial to Assess Crestal Bone Remodeling of Four Different Implant Designs

February 6, 2025 updated by: University Ghent

This randomized controlled trial aimed to assess the effect of the implant neck design (microthreaded vs. non-microthreaded) as well as the type of abutment connection (internal conical vs. external flat-to-flat) on long-term crestal bone remodelling and peri-implant health. Four implants used for a bar-retained maxillary overdenture, were followed over a period of at least 6 years.

Twenty-five patients were treated with a bar-retained maxillary overdenture. Four different implants were placed, with respectively: internal connection and microthreads on the implant neck (I MT); internal connection, without microthreads (I NMT); external connection, with microthreads (E MT); and external connection, without microthreads (E NMT). Other design features, s.a. diameter, surface topography, extent of platform switch as well as the surgical and prosthetic treatment protocol were identical. Radiographic crestal bone loss (CBL), plaque score (PS), bleeding on probing (Bop) and probing pocket depth (PPD) were determined at 1 and 6 years after implant placement.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

25

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

  • Belgium
      • Ghent, Belgium
        • Ghent University

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Edentulous in the maxilla and sufficient bone to harvest four 4 x 9 mm implant

Exclusion Criteria:

  • Head -and neck radiation
  • Bisphosphonate intake
  • Limited prosthetic height

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: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Internal Microthread implant
Each participant received 4 implants, one of each type
Device: Implant placement
Each patient received 4 implants to support a bar supported overdenture. One implant is commercially available, 3 implants were experimentally made by the manufacturer for this study. The implants were similar in macro-desing, surface and platform shift but differ in microthread design and implant-abutment connection.
Experimental: Internal Non Microthread implant
Device: Implant placement
Each patient received 4 implants to support a bar supported overdenture. One implant is commercially available, 3 implants were experimentally made by the manufacturer for this study. The implants were similar in macro-desing, surface and platform shift but differ in microthread design and implant-abutment connection.
Experimental: External microthread implant
Device: Implant placement
Each patient received 4 implants to support a bar supported overdenture. One implant is commercially available, 3 implants were experimentally made by the manufacturer for this study. The implants were similar in macro-desing, surface and platform shift but differ in microthread design and implant-abutment connection.
Experimental: External Non-Microthread implant
Device: Implant placement
Each patient received 4 implants to support a bar supported overdenture. One implant is commercially available, 3 implants were experimentally made by the manufacturer for this study. The implants were similar in macro-desing, surface and platform shift but differ in microthread design and implant-abutment connection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Crestal bone loss
Time Frame: The measurements were performed at 1 and 6 years
Radiographic measurement of crestal bone loss
The measurements were performed at 1 and 6 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Plaque
Time Frame: The measurements were performed at 1 and 6 years
Plaque was measured at 4 sites on each implant
The measurements were performed at 1 and 6 years
Probing pocket depth
Time Frame: The measurements were performed at 1 and 6 years
The measurements were performed at 1 and 6 years
Bleeding on probing
Time Frame: The measurements were performed at 1 and 6 years
The measurements were performed at 1 and 6 years

Collaborators and Investigators

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

Sponsor

University Ghent

Investigators

  • Principal Investigator: Hugo De Bruyn, University Ghent

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

September 18, 2015

Primary Completion (Actual)

February 20, 2024

Study Completion (Actual)

February 20, 2024

Study Registration Dates

First Submitted

February 6, 2025

First Submitted That Met QC Criteria

February 6, 2025

First Posted (Actual)

March 25, 2025

Study Record Updates

Last Update Posted (Actual)

March 25, 2025

Last Update Submitted That Met QC Criteria

February 6, 2025

Last Verified

June 1, 2015

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • EC/2015/0338/AM02

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

product manufactured in and exported from the U.S.

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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