Bond, Pair
Conditions
Brief 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.
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.
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.
Participants will receive a conventional fixed bonded lingual retainer (canine-to-canine) fabricated using multistranded stainless steel wire and bonded using standard clinical procedures.
Sponsors
Amany Ibrahim
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
13 Years to 35 Years
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
* 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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| bond failure | immediate (within 24 hours after bonding) and at 3, 6, 9, and 12 months | Bond failure will be assessed clinically by detecting any detachment of the retainer from the tooth surface (number of debonded teeth). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| chairside time | Periprocedural (during retainer bonding procedure on Day 1) | 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) |
| wire breakage | Every 3months for 12 months | — |
| plaque accumulation | Baseline (before retainer bonding) and at 3, 6, 9, and 12 months | 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. |
| posttreatment relapse | Baseline (before retainer bonding) and at 12 months | 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. |
Countries
Egypt
Outcome results
None listed