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CompletedNCT07538869Updated Apr 20, 2026

Comparison of 3D Printed Metal Fixed Retainer Versus Conventional Fixed Bonded Retainer

An interventional study of bar 3d printed metal fixed retainer and conventional fixed retainer in Bond, Pair, sponsored by Amany Ibrahim. Completed at 1 site in Egypt. Open to participants aged 13 Years to 35 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-20.

Sponsored by Amany Ibrahim · Not applicable, Interventional, and Other

From the registry’s dates

  • Registered 1 year after the study started (first participant enrolled Apr 2025, registered Apr 2026).
Phase
Not applicable
Study type
Interventional
Enrollment
64
Allocation
Randomized
Ages
13 Years to 35 Years
Sex
All
01

Study summary

Despite the growing diversity of materials used for mandibular fixed retainers, the evidence base remains inconclusive. In particular, conflicting findings have been reported regarding the bond failure of titanium retainers across different evaluation periods, including immediate and 12-month outcomes. Additionally, the emergence of 3D metal-printed retainers has not yet been matched by sufficient clinical evidence, with current data being limited and lacking long-term validation.

Read the detailed description

In recent years, CAD/CAM technology and 3D printing have introduced new possibilities in orthodontic practice, with expanding applications across various treatment modalities. Additive manufacturing, commonly known as 3D printing, enables the fabrication of objects through the sequential layering of material to produce precise three-dimensional structures. While orthodontists are already familiar with 3D-printed appliances such as clear aligners, the application of these technologies in fixed retention is still evolving. Recent studies have reported the fabrication of customized lingual retainers using CAD/CAM techniques, including nickel-titanium-milled retainers and zirconia bars designed for use as bonded mandibular fixed retainers.

02

Conditions studied

  • Bond, Pair
03

In context

Lead sponsor

This is the only study on the registry with Amany Ibrahim as lead sponsor.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
13 Years to 35 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • Age ≥ 13 years
  • Complete permanent dentition up to second molars
  • Completed Class I orthodontic treatment and requiring a mandibular fixed -bonded retainer
  • No sex predilection.

Exclusion criteria

Exclusion Criteria:

  • Enamel defects that may compromise bonding (e.g., hypoplasia, fluorosis)
  • Poor oral hygiene
  • Active dental or periodontal pathology at the site of intervention
  • Lingual restorations on mandibular anterior teeth
  • Poor compliance or inability to attend follow-up visits
  • Psychological or medical conditions that may interfere with study participation
05

Study design

Phase
Not applicable
Primary purpose
Other
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Single (Outcomes assessor)
Enrollment
64 participants (actual)

Study arms

  • Active comparator
    Conventional fixed bonded retainer

    Device: conventional fixed retainer

  • Experimental
    Bar 3d printed metal fixed retainer

    Device: bar 3d printed metal fixed retainer

Interventions

  • Devicebar 3d printed metal fixed retainer

    Participants will receive a custom-designed 3D-printed metal fixed retainer. The retainer is digitally designed using intraoral scans and fabricated using metal 3D printing technology to achieve a precise fit tailored to each patient.

  • Deviceconventional fixed retainer

    Participants will receive a conventional fixed bonded lingual retainer (canine-to-canine) fabricated using multistranded stainless steel wire and bonded using standard clinical procedures.

06

What researchers measure

Primary outcomes

  1. bond failure

    Bond failure will be assessed clinically by detecting any detachment of the retainer from the tooth surface (number of debonded teeth).

    Time frame: immediate (within 24 hours after bonding) and at 3, 6, 9, and 12 months

Secondary outcomes

  1. chairside time

    Time measurement will start from the beginning of acid etching of the teeth and end after completion of composite curing for all bonded teeth. The duration will be recorded in minutes using a digital stopwatch by an independent assessor using a digital stopwatch (minutes)

    Time frame: Periprocedural (during retainer bonding procedure on Day 1)

  2. wire breakage

    Time frame: Every 3months for 12 months

  3. plaque accumulation

    Plaque accumulation will be assessed using the Silness-Löe Plaque Index, which scores plaque presence on the tooth surface adjacent to the fixed retainer. Each tooth will be scored on a scale from 0 to 3: 0: No plaque 1. Thin film of plaque detectable by probe 2. Moderate accumulation visible to the naked eye 3. Abundant plaque accumulation Assessment will be performed by direct intraoral clinical examination using a dental mirror and probe by a calibrated examiner. The outcome will be reported as the mean plaque index score per patient at each time point.

    Time frame: Baseline (before retainer bonding) and at 3, 6, 9, and 12 months

  4. posttreatment relapse

    Post-treatment relapse will be assessed using Little's Irregularity Index, which measures the linear displacement of the anatomic contact points of the mandibular anterior teeth. Relapse will be calculated as the difference in Little's Irregularity Index between baseline (pre-retention) and 12 months follow-up.

    Time frame: Baseline (before retainer bonding) and at 12 months

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Study locations

1 site
  • Amany Eltantawy
    Giza, Cairo University, Egypt
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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Apr 20, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT07538869
Lead sponsor
Amany Ibrahim
Responsible party
Amany Ibrahim (assistant lecturer, Cairo University) — Sponsor-investigator
First posted
Apr 20, 2026
Start date
Apr 1, 2025
Primary completion
Oct 1, 2025
Completion
Oct 1, 2025
Last update
Apr 20, 2026

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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This study is completed, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.

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