Dental Implant Bone LossNCT06821308
A Randomized Controlled Clinical Trial to Assess Crestal Bone Remodeling of Four Different Implant Designs
A study testing Implant placement in people with Dental Implant Bone Loss, run by University Ghent at 1 site in Belgium.
Trial 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. Read more about this study
- Who is it for?
- Ages 21 years and olderHealthy volunteers can take part
- Conditions the study is for
- Dental Implant Bone Loss
- What is being tested?
- Implant placement
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 25 participants
- Where
- 1 siteBelgium
- Study dates
- 18 Sep 2015to 20 Feb 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Edentulous in the maxilla and sufficient bone to harvest four 4 x 9 mm implant
Who cannot join
- Head -and neck radiation
- Bisphosphonate intake
- Limited prosthetic height
Trial locations and contacts
1 site in 1 country.
About this study
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.
- Conditions
- Dental Implant Bone Loss
- Being tested
- Implant placement
- Keywords
- Dental implant, crestal bone loss, microthreads, implant-abutment connection
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
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.
| Study group | Role | What they receive |
|---|---|---|
| Internal Microthread implant | Active comparator | Each participant received 4 implants, one of each type Receives: Device: Implant placement |
| Internal Non Microthread implant | Experimental | Not described Receives: Device: Implant placement |
| External microthread implant | Experimental | Not described Receives: Device: Implant placement |
| External Non-Microthread implant | Experimental | Not described Receives: Device: Implant placement |
What is being measured
The primary outcome is the main question the study is designed to answer.
Crestal bone loss
Radiographic measurement of crestal bone loss
Measured: The measurements were performed at 1 and 6 years
Secondary outcomes (3)
Plaque
Plaque was measured at 4 sites on each implant
Measured: The measurements were performed at 1 and 6 years
Probing pocket depth
Measured: The measurements were performed at 1 and 6 years
Bleeding on probing
Measured: The measurements were performed at 1 and 6 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Feb 2025
- Study start18 Sep 2015
- Primary completion20 Feb 2024
- Study completion20 Feb 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Dental Implant Bone LossStudies of the same condition, open and under way.
- More trials run by University GhentThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Split-mouth study
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 25 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Ghent
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Hugo De Bruyn, Principal investigator, University Ghent
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06821308
- Sponsor's protocol ID
- EC/2015/0338/AM02
- Status last verified
- Jun 2015
- First submitted
- 6 Feb 2025
- Last updated
- 11 Feb 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
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.
PubMed 34378860Glibert 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.
PubMed 29575488Matthijs 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.
PubMed 40552788
Study at a glance
From the registry record, last updated by the sponsor on 11 Feb 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized Controlled Clinical Trial to Assess Crestal Bone Remodeling of Four Different Implant Designs
- ClinicalTrials.gov ID
- NCT06821308
- Acronym / sponsor ID
- EC/2015/0338/AM02
- Conditions
- Dental Implant Bone Loss
- Keywords
- Dental implant, crestal bone loss, microthreads, implant-abutment connection
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 25 participants (actual)
- Lead sponsor
- University GhentUniversity, hospital or other
- Study start
- 18 Sep 2015 (actual)
- Primary completion
- 20 Feb 2024 (actual)
- Study completion
- 20 Feb 2024 (actual)
- First posted
- 11 Feb 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 4
- Model description
- Split-mouth study
| Arm | Type | Receives |
|---|---|---|
| Internal Microthread implant | Active comparator | Device: Implant placementEach participant received 4 implants, one of each type |
| Internal Non Microthread implant | Experimental | Device: Implant placement |
| External microthread implant | Experimental | Device: Implant placement |
| External Non-Microthread implant | Experimental | Device: Implant placement |
Who may qualify
- Ages
- 21 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Edentulous in the maxilla and sufficient bone to harvest four 4 x 9 mm implant
Key exclusion criteria (3 listed)
- Head -and neck radiation
- Bisphosphonate intake
- Limited prosthetic height
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Implant placementEach 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. | Device | External Non-Microthread implant, External microthread implant, Internal Microthread implant, Internal Non Microthread implant |
Primary outcome
Crestal bone loss
Time frame: The measurements were performed at 1 and 6 years
Radiographic measurement of crestal bone loss
3 secondary outcomes
Plaque
Time frame: The measurements were performed at 1 and 6 years
Probing pocket depth
Time frame: The measurements were performed at 1 and 6 years
Bleeding on probing
Time frame: The measurements were performed at 1 and 6 years
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Feb 2025.
- Results publication: PubMed 34378860Doornewaard 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.
- Results publication: PubMed 29575488Glibert 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.
- Derived from this study: PubMed 40552788Matthijs 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.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Hugo De Bruyn principal investigator
University Ghent
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Implant placement in people with Dental Implant Bone Loss, run by University Ghent at 1 site in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Feb 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Crestal bone loss (time frame: The measurements were performed at 1 and 6 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06821308, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Feb 2025.