NCT06821308

Brief Summary

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.

Trial Health

87
On Track

Trial Health Score

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

Enrollment
25

participants targeted

Target at below P25 for not_applicable

Timeline
Completed

Started Sep 2015

Longer than P75 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

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

September 18, 2015

Completed
8.4 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

February 20, 2024

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

February 20, 2024

Completed
12 months until next milestone

First Submitted

Initial submission to the registry

February 6, 2025

Completed
5 days until next milestone

First Posted

Study publicly available on registry

February 11, 2025

Completed
Last Updated

February 11, 2025

Status Verified

June 1, 2015

Enrollment Period

8.4 years

First QC Date

February 6, 2025

Last Update Submit

February 6, 2025

Conditions

Dental Implant Bone Loss

Keywords

Dental implant, crestal bone loss, microthreads, implant-abutment connection

Outcome Measures

Primary Outcomes (1)

  • Crestal bone loss

    Radiographic measurement of crestal bone loss

    The measurements were performed at 1 and 6 years

Secondary Outcomes (3)

  • Plaque

    The measurements were performed at 1 and 6 years

  • Probing pocket depth

    The measurements were performed at 1 and 6 years

  • Bleeding on probing

    The measurements were performed at 1 and 6 years

Study Arms (4)

Internal Microthread implant

ACTIVE COMPARATOR

Each participant received 4 implants, one of each type

Device: Implant placement

Internal Non Microthread implant

EXPERIMENTAL
Device: Implant placement

External microthread implant

EXPERIMENTAL
Device: Implant placement

External Non-Microthread implant

EXPERIMENTAL
Device: Implant placement

Interventions

Implant placementDEVICE

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.

External Non-Microthread implantExternal microthread implantInternal Microthread implantInternal Non Microthread implant

Eligibility Criteria

Age21 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

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

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Ghent University

Ghent, Belgium

Location

Related Publications (3)

  • Doornewaard R, Sakani S, Matthys C, Glibert M, Bronkhorst E, Vandeweghe S, Vervaeke S, De Bruyn H. Four-implant-supported overdenture treatment in the maxilla. Part I: A randomized controlled split mouth trial assessing the effect of microthreads and abutment connection type on 4 years peri-implant health. Clin Implant Dent Relat Res. 2021 Oct;23(5):671-679. doi: 10.1111/cid.13037. Epub 2021 Aug 11.

    PMID: 34378860BACKGROUND

  • Glibert M, Vervaeke S, Jacquet W, Vermeersch K, Ostman PO, De Bruyn H. A randomized controlled clinical trial to assess crestal bone remodeling of four different implant designs. Clin Implant Dent Relat Res. 2018 Aug;20(4):455-462. doi: 10.1111/cid.12604. Epub 2018 Mar 25.

    PMID: 29575488BACKGROUND

  • Matthijs S, Christiaens V, Matthys C, De Bruyn H, Glibert M. A 6-Year Randomized Controlled Trial on Different Implant Designs in Maxillary Overdenture Patients. Clin Implant Dent Relat Res. 2025 Jun;27(3):e70069. doi: 10.1111/cid.70069.

    PMID: 40552788DERIVED

Study Officials

  • Hugo De Bruyn

    University Ghent

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
PARTICIPANT
Purpose
TREATMENT
Intervention Model
PARALLEL
Model Details: Split-mouth study
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

February 6, 2025

First Posted

February 11, 2025

Study Start

September 18, 2015

Primary Completion

February 20, 2024

Study Completion

February 20, 2024

Last Updated

February 11, 2025

Record last verified: 2015-06

Data Sharing

IPD Sharing
Will not share

Locations

BE(1)