Overview
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.
Eligibility
Inclusion Criteria:
- 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.
Exclusion Criteria:
- 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).