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Dental ImplantsNCT03837158

Titanium Zirconium (TiZr) Mini Implants

A study testing early loading and immediate loading in people with Dental Implants, run by University of Bern at 2 sites in Switzerland.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

H0: "Within the first year post-placement, four interforaminally placed, immediately loaded 2.4 mm narrow-diameter one-piece TiZr implants with miniaturized stud-type attachments show improved patient-reported outcome measures (PROMS) compared to two interforaminally placed, early loaded, TiZr two-piece implants with… Read more about this study

Who is it for?
Ages 18 years and olderHealthy volunteers can take part
Conditions the study is for
Dental Implants
What is being tested?
early loading and immediate loading
Type of treatment
Surgery or procedure
Could I receive a placebo?
No, everyone receives an active treatment
How many people
72 participants
Where
2 sitesSwitzerland
Study dates
1 Sep 2019to Aug 2033
Phase
Interventional
Are there results?
Not yet: the study is under way

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 18 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • At patient level:
  • Written informed consent
  • Age ≥ 18 years
  • Sufficient complete dentures (Marxkors and Ferger, 1989) not older than 1 year
  • Patient is unsatisfied with mandibular denture to the degree that he/she seeks treatment
  • At site level:
Show all 10Show fewer
  • Healed edentulous mandible (minimum 8 weeks since last extraction)
  • Minimal ridge dimensions 5.5 mm (width) by 12 mm (height) in the anterior (interforaminal) area, allowing the placement of 3.3 (endosseous diameter) by 10 mm (length) implants
  • Opposing dentition: complete denture on a edentulous maxilla
  • Physical status (PS) 1 and 2 (American Society of Anesthesiologists)

Who cannot join

  • At patient level
  • Any physical or mental disorder that would interfere with the ability to perform adequate oral hygiene or the capability of providing written informed consent and compliance to the protocol
  • Any disorder that would interfere with wound healing or represent a contraindication for oral surgery such as, but not limited to, uncontrolled diabetes or conditions resulting in or requiring immunosuppression, radiation, chemotherapy, frequent use of antibiotics or antiresorptive medication such as bisphosphonates
  • Pregnancy or lactation
  • Heavy smoking habit with > 20 cig/d
  • Severe bruxism or clenching habits, present oro-facial pain
  • At site level:
  • Ridge defects requiring staged bone augmentation procedures (simultaneous Guided Bone Regeneration (GBR) within the ridge contour allowed)

Trial locations and contacts

2 sites in 1 country.

Switzerland2 sites

  • University of Bern

    Bern, 3010

  • Private Practice Dr. B. Wallkamm

    Langenthal, Canton of Bern, 4900

Other trials in Switzerland

About this study

Official title: Is the Stabilization of a Mandibular Overdenture Employing Four Novel One-piece Immediately Loaded TiZr Implants With Miniaturized Stud-type Attachments a Feasible Alternative to Two Two-piece Early Loaded Tissue-level Implants With Regular Stud-type Attachments?

H0: "Within the first year post-placement, four interforaminally placed, immediately loaded 2.4 mm narrow-diameter one-piece TiZr implants with miniaturized stud-type attachments show improved patient-reported outcome measures (PROMS) compared to two interforaminally placed, early loaded, TiZr two-piece implants with stud-type attachments to retain a mandibular overdenture."The specific aim is to compare both treatment alternatives to evaluate which one may be recommended for elderly edentulous patients.

Conditions
Dental Implants
Being tested
early loading, immediate loading

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • early loadingProcedure or surgery

    two TiZr implants on SLA surface

  • immediate loadingProcedure or surgery

    four TiZr implants on SLA surface

Study groups in NCT03837158
Study groupRoleWhat they receive
Control-groupExperimentalTwo Tissue Level TiZr Sand blasted long grit acid-etched (SLA) implants placed in positions 33 and 43 (diameter 3.3mm, length ≥10mm), early loading
Receives: Procedure: early loading
Experimental-groupExperimentalFour narrow-diameter implants (NDI) TiZr SLA implants in positions 34, 32, 42, and 44 (diameter 2.4mm, length ≥10mm), immediate loading
Receives: Procedure: immediate loading

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Geriatric Oral Health Assessment Index (GOHAI)

    Change from baseline questionnaires in Oral Health Related Quality of Life (OHRQoL).

    Scores 0-60: higher values represent lower OHRQoL

    Measured: One-year follow-up

Secondary outcomes (12)

  1. Additional Oral Health Impact Profile for edentulism (OHIP-EDENT)

    Change from baseline questionnaires

    Measured: Follow-up (up to 365 days)

  2. Additional PROM Denture Satisfaction Index (DSI)

    Change in Denture Satisfaction higher values represent better satisfaction (0-1200mm)

    Measured: Baseline, follow-up (up to 365 days)

  3. Implant Survival

    Survival (yes/no)

    Measured: at implant loading (at 24 hours for arm B, at 6-8 weeks for arm A), at the one-year follow-up

  4. Implant Success

    Success according to Misch (2007) Misch criteria scores 1-4: higher values represent better success

    Measured: at implant loading (at 24 hours for arm B, at 6-8 weeks for arm A), at the one-year follow-up

  5. Prosthetic Survival

    Prosthetic Survival (yes/no): is the denture still in place?

    Measured: Baseline, follow-up (up to 365 days)

  6. Chewing Efficiency

    Color mixing test

    Measured: Baseline, follow-up (up to 365 days)

  7. Plaque Index

    Plaque Index Scores 0-3 3= thick plaque is visible along gingival margin 2= plaque is visible along gingival margin, with or without air drying

    1= following air drying, plaque is not visible but can be wiped off with an explorer 0= following air drying, plaque is not visible nor can be wiped off with an explorer

    Measured: at implant loading (at 24 hours for arm B, at 6-8 weeks for arm A), at the one-year follow-up

  8. Bleeding Index

    Bleeding Index Scores 0-3 0= Healthy gingival

    1. Gingival look inflamed, but don't bleed when probed
    2. Gingival look inflamed and bleed when probed
    3. Ulceration and spontaneous bleeding

    Measured: at implant loading (at 24 hours for arm B, at 6-8 weeks for arm A), at the one-year follow-up

  9. Pocket Probing depth

    depth measured in mm

    Measured: at implant loading (at 24 hours for arm B, at 6-8 weeks for arm A), at the one-year follow-up

  10. Time-Cost-Analysis

    Total treatment time will be collected and added. Total treatment cost will be evaluated and a ratio will be calculated. The groups will be compared on the base of this ration

    Measured: After surgery, after implants loading, after follow-up (up to 365 days)

  11. Cost Effectiveness and Willingness to Pay

    Cost effectiveness wil be calculated as a ratio of treatment cost in relation to change of GOHAI sum score. This will allow to evaluate how much monetary item is needed to achieve a change in GOHAI

    Measured: Total change and time at 1y follow-up

  12. In-vivo evaluated loss of retentive force

    Measurement with a hand-held digital force gauge

    Measured: after implant loading (expected to be after 6 weeks on average) and at follow-up (up to 365 days)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted12 Feb 2019
  2. Study start1 Sep 2019
  3. Primary completion10 Sep 2024
  4. Study completionAug 2033 (estimated)

Resources

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
Masking
None (open label)
Enrolment
72 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03837158
Sponsor's protocol ID
Mini 1286_2018
Status last verified
Feb 2026
First submitted
30 Jan 2019
Last updated
18 Feb 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: It is not planned to use the data of this study for future research.

Publications

  • Schimmel M, Leles CR, Schenk N, Janner SFM, Wallkamm B, Suter VGA, Abou-Ayash S, Raabe C. Mandibular Overdentures on Four Immediately Loaded Mini-Implants Versus Two-Delayed Loaded Regular Implants: 1-Year, Two-Center RCT on Patient-Reported Outcomes. Clin Oral Implants Res. 2026 Aug;37(8):983-993. doi: 10.1111/clr.70143. Epub 2026 Jun 1.

    PubMed 42226346

Questions about this trial

What is this clinical trial studying?

A study testing early loading and immediate loading in people with Dental Implants, run by University of Bern at 2 sites in Switzerland.

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 10 inclusion and 8 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: under way, not looking for participants, as of the sponsor's last update on 18 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in Switzerland. 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?

This study is still under way. Results are not available in the source record yet.

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?

Geriatric Oral Health Assessment Index (GOHAI) (time frame: One-year follow-up). 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 NCT03837158, which also lists 1 linked publication.

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 18 Feb 2026.

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