Effectiveness of Gold Fixed Retainers Compared to Conventional Stainless Steel Retainers

NCT07280455 | Recruiting

• 1 other identifier: UOB-RCT-ORTHO-GOLDSS-2025
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

This randomized clinical trial will compare the effectiveness of a gold-plated multistranded mandibular fixed retainer versus a conventional multistranded stainless-steel fixed retainer in maintaining lower anterior tooth alignment after completion of orthodontic treatment. Eligible participants (post-orthodontic patients requiring mandibular fixed retention) will be allocated in a 1:1 ratio to receive either a gold-plated 0.0195-inch multistranded retainer or an identical-gauge 0.0195-inch stainless-steel multistranded retainer. Participants will be followed for 6 months. The primary outcome is post-treatment stability of mandibular anterior alignment, assessed by changes in Little's Irregularity Index over time, along with retainer failure outcomes (e.g., time to first failure and tooth-level failure events). Secondary outcomes include periodontal health indices and related clinical measures collected at baseline and follow-up visits. For the microbiological assessment, plaque/biofilm will be collected from the retainer using sterile swabs at 1 month, 3 months, and 6 months to evaluate bacterial levels associated with each retainer material.

Conditions

Orthodontic Retention Appliance; Orthodontic Relapse

Keywords

fixed retainer; gold-coated retainer wire; stainless steel retainer wire; Little's Irregularity Index; retainer failure; periodontal indices

Outcome Measures

Primary Outcomes (2)

• Change in mandibular incisor alignment (Little's Irregularity Index, ΔLII)

  Little's Irregularity Index (LII) is a quantitative scale of mandibular anterior alignment, calculated as the sum of the linear displacements (in mm) of the contact points of the six mandibular anterior teeth. Scores range from 0 mm (perfect alignment, no irregularity) to ≥10 mm (very severe irregularity); higher scores indicate greater crowding and therefore a worse outcome. LII will be measured for the mandibular anterior teeth (canine-to-canine) at baseline (T0, before fixed-retainer placement) and at follow-up visits (T1 = 1 month, T2 = 3 months, T3 = 6 months). The primary endpoint is the change in LII (follow-up LII minus baseline LII), comparing gold-plated versus stainless-steel fixed-retainer groups.

  Baseline (T0) to 6 months after retainer placement (assessed at 1, 3, and 6 months)

• Time to first fixed-retainer failure (survival)

  Time (days) from fixed retainer bonding to the first failure event requiring repair/rebonding/replacement. Failures will be recorded and classified (e.g., adhesive-enamel debond, wire-composite debond, wire fracture, partial/complete loosening) and compared between groups.

  From retainer placement to 6 months after placement.

Secondary Outcomes (8)

• Plaque accumulation at mandibular anterior teeth (Silness-Löe Plaque Index)

  Baseline and 1, 3, and 6 months.

• Microbiological plaque outcome

  Follow-up visits at 1 month (T1), 3 months (T2), and 6 months (T3) after retainer placement.

• Change in mandibular inter-canine width

  Baseline (T0, before retainer placement) and follow-up visits at 1 month (T1), 3 months (T2), and 6 months (T3).

• Gingival inflammation at mandibular anterior teeth (Löe-Silness Gingival Index)

  Baseline and 1, 3, and 6 months after retainer placement.

• Probing pocket depth at mandibular anterior teeth

  Baseline and 1, 3, and 6 months after retainer placement.

Study Arms (2)

Gold-coated fixed retainer wire

EXPERIMENTAL

Participants will receive a mandibular canine-to-canine fixed retainer fabricated and bonded using the standardized protocol. The allocated device is a 0.0195-inch gold-plated multistranded wire (penta twist, five-strand).

Device: Gold-coated fixed retainer wire

Stainless steel fixed retainer wire

ACTIVE COMPARATOR

Participants will receive a mandibular canine-to-canine fixed retainer fabricated and bonded using the standardized protocol. The allocated device is a 0.0195-inch dead-soft multistranded stainless-steel wire (coaxial, six-strand).

Device: Stainless steel fixed retainer wire

Interventions

Gold-coated fixed retainer wire DEVICE

Participants will receive a bonded mandibular fixed retainer extending canine-to-canine. The retainer will be fabricated using a gold-coated retainer wire and bonded to the lingual surfaces of the mandibular anterior teeth using standard orthodontic bonding procedures. After placement, participants will be followed at scheduled visits (baseline and follow-ups at 1 month, 3 months, and 6 months) to evaluate clinical stability and retainer performance. At each follow-up visit, the retainer will be clinically examined for integrity, and any failure/complication events will be recorded (e.g., debonding/loosening, fracture, or need for repair). Clinical outcome assessments will include mandibular anterior alignment/stability (Little's Irregularity Index), periodontal indices, and occlusal assessment, Microbiological sampling will consist of plaque/swab samples collected at each follow-up visit.

Gold-coated fixed retainer wire

Stainless steel fixed retainer wire DEVICE

Participants will receive a bonded mandibular fixed retainer extending canine-to-canine. The retainer will be fabricated using a conventional stainless steel retainer wire and bonded to the lingual surfaces of the mandibular anterior teeth using standard orthodontic bonding procedures. After placement, participants will be followed at scheduled visits (baseline and follow-ups at, 1 month, 3 months, and 6 months) to evaluate clinical stability and retainer performance. At each follow-up visit, the retainer will be clinically examined for integrity, and any failure/complication events will be recorded (e.g., debonding/loosening, fracture, or need for repair). Clinical outcome assessments will include mandibular anterior alignment/stability (Little's Irregularity Index), periodontal indices, and occlusal assessment. Microbiological sampling will consist of plaque/swab samples collected at each follow-up visit.

Stainless steel fixed retainer wire

Eligibility Criteria

• Age: 15 Years - 30 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Age: 15-30 years.
• Patients who have completed comprehensive orthodontic treatment ,with well-aligned mandibular anterior teeth (Little's Irregularity Index ≤ 0.5 mm) at debond; both extraction and non-extraction cases are eligible.
• Patients with good oral hygiene and healthy periodontium at baseline; no previous bonded retainer.
• All mandibular anterior teeth present (canine-canine), with sound lingual enamel suitable for bonding.

You may not qualify if:

• Patients with a history of rapid maxillary expansion (RME) or surgically assisted RME (SARME).
• Patients with a cleft lip / and or palate (craniofacial anomalies).
• Patients with marked deep overbite and/or parafunctional habits (e.g., bruxism, clenching).
• Patients with conditions precluding reliable bonding in the mandibular anterior segment (active caries, extensive restorations, enamel fractures) or missing teeth from canine to canine.
• Patients with medical/periodontal conditions likely to affect gingival health (e.g., active periodontitis, uncontrolled systemic disease).

Sponsors & Collaborators

• Noor Sattar Raheem: lead

Study Sites (1)

College of Dentistry, University of Baghdad - Orthodontic Clinics

Baghdad, Baghdad Governorate, Iraq

RECRUITING

Study Officials

• NOOR NOOR, BDS

  noor sattar

  PRINCIPAL INVESTIGATOR

Central Study Contacts

NOOR Raheem, BDS

CONTACT

+9647704514927; Noor.sattar2403@codental.uobaghdad.edu.iq

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Masking Details: Masking is used for participants, outcome assessors, and the data analyst. The treating orthodontist (care provider) who places the fixed retainer cannot be blinded due to visible differences between the retainer wire types. Participants are not informed of group assignment. Outcome assessments are performed on coded study records/models by a blinded examiner, and the dataset is coded prior to statistical analysis, which is conducted by a blinded data analyst.
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Postgraduate Researcher (Principal Investigator)

Study Record Dates

• First Submitted: December 1, 2025
• First Posted: December 12, 2025
• Study Start: November 1, 2025
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): December 1, 2026
• Last Updated: December 12, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

IR (1)