The Effect of Full Versus Partial Coverage Thermoformed Retainers in Dual Retention With a Lower Bonded Retainer, on Periodontal, Orthodontic, and Patient-Reported Outcomes

NCT07669129 | Not Yet Recruiting

• 1 other identifier: DF CD2609/0046 (P)
• Study Type: interventional
• Target: 42
• Locations: 1 country
• Sites: 1

Brief Summary

After braces are removed, teeth may move back toward their original positions. Retainers are used to help keep teeth straight after orthodontic treatment. This study compares two types of clear removable retainers used together with a fixed wire retainer behind the lower front teeth. One retainer covers the entire inner surface of the teeth (full coverage), while the other covers only part of the inner surface (partial coverage). The purpose of this study is to find out whether the two retainer designs differ in their effects on gum health, comfort, retainer breakages, stability of the orthodontic correction, comfort, and compliance. The findings from this study may help orthodontists choose the most suitable retainer design for future patients. Participants in this study will receive a fixed wire retainer on the lower front teeth and upper and lower clear removable retainers. They will be randomly assigned to receive either the full coverage or partial coverage lower retainer. Participants will attend follow-up visits at 1 month, 3 months, and 6 months after starting retainer wear. At these visits, the orthodontist will examine the teeth, gums, and retainers, and participants will complete a short questionnaire about their experience wearing the retainer. This study excluded participants who are pregnant or breastfeeding within the first 6 months, have uncontrolled medical conditions or gum disease, smoke or vape, require a Hawley retainer instead of a clear retainer, or have missing front teeth or certain jaw conditions. Participants may benefit from receiving retainers, oral hygiene care, and regular monitoring of their teeth and gum health at no additional cost. Participants will also receive an oral care kit during the debond appointment and at the 3-month and 6-month review visits. Possible risks include breakage of the retainers, which may require repair or replacement, gum problems if oral hygiene is not maintained, and slight tooth movement despite retainer use. If gum problems develop, appropriate cleaning and referral for further treatment may be provided. Replacement retainers required during the study period will be provided free of charge.

Conditions

Orthodontic Retention

Keywords

Orthodontic retention; clear retainer; fixed bonded retainer; periodontal health; breakage

Outcome Measures

Primary Outcomes (6)

• Full mouth plaque score

  To evaluate full mouth plaque score associated with clear retainers with partial or full coverage designs when used in conjunction with fixed bonded retainers in the lower arch. Scale title: Full mouth plaque score Minimum value: 0% Maximum value: 100% Higher score means indicate worse plaque accumulation and poorer oral hygiene. (worse outcome)

  baseline, 1 month, 3 months and 6 months

• Full mouth bleeding on probing score

  To evaluate full mouth bleeding on probing score associated with clear retainers with partial or full coverage designs when used in conjunction with fixed bonded retainers in the lower arch. Scale title: Full mouth bleeding on probing score Minimum value: 0% Maximum value: 100% Higher score means indicate worse periodontal health (worse outcome)

  Baseline, 1 month, 3 months and 6 months

• Periodontal probing depth of lower anterior teeth

  To evaluate periodontal probing depth of lower anterior teeth associated with clear retainers with partial or full coverage designs when used in conjunction with fixed bonded retainers in the lower arch Scale title: Periodontal probing depth Minimum value: 0mm Maximum value: No fixed upper limit Higher score means indicate worse periodontal health (worse outcome)

  baseline, 1 month, 3 months and 6 months

• Gingival recession on lower anterior teeth

  To evaluate gingival recession on lower anterior teeth associated with clear retainers with partial or full coverage designs when used in conjunction with fixed bonded retainers in the lower arch Scale title: Gingival recession Minimum value: 0mm Maximum value: No fixed upper limit Higher score means indicate worse periodontal health (worse outcome)

  Baseline, 1 month, 3 months and 6 months

• Integrity of clear retainer

  To evaluate the incidence of clear retainer breakages associated with partial or full coverage designs when used in combination with fixed bonded retainers in the lower arch

  3 months and 6 months

• Breakages of fixed bonded retainers

  To evaluate the incidence of breakages involving bonded wire or adhesive resin of fixed bonded retainers when used in combination with clear retainers in either partial or full coverage designs in the lower arch.

  1 month, 3 months, 6 months

Secondary Outcomes (3)

• Stability of lower anterior teeth

  Baseline, 3 months, 6 months

• Quality of Life in Patients Wearing Orthodontic Retainers

  3 months and 6 months

• Patient's compliance

  3 months and 6 months

Study Arms (2)

Full coverage clear retainer

ACTIVE COMPARATOR

A removable lower retainer covers the entire inside surface of lower teeth including the fixed bonded retainer

Device: Full coverage Vivera retainer

Partial coverage clear retainer

ACTIVE COMPARATOR

A removable lower retainer covers part of inside surface of lower teeth excluding the fixed bonded retainer

Device: Partial coverage vivera retainer

Interventions

Full coverage Vivera retainer DEVICE

A removable lower retainer (Vivera retainer) with full coverage design which covers the entire inside surface of lower teeth including the fixed bonded retainer

Full coverage clear retainer

Partial coverage vivera retainer DEVICE

A removable lower retainer (Vivera retainer) with partial coverage design which covers part of the inside surface of lower teeth excluding the fixed bonded retainer

Partial coverage clear retainer

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Aged over 18 years.
• Controlled systemic diseases and conditions.
• Probing pocket depth ≤ 3 mm
• Bleeding on probing \< 10 per cent
• Full mouth plaque scores of less than 20 per cent
• Just completed active orthodontic treatment involving lower arch
• Patient consent to dual retention in the lower arch

You may not qualify if:

• Require a Hawley retainer in the lower arch.
• Patients in retention phase requiring replacement of retainers
• Uncontrolled systemic disease, including chronic or metabolic diseases.
• Pregnant or lactating mothers within six months postpartum.
• Taking medications that affect gingival health and architecture.
• Have one or more missing anterior teeth.
• Have congenital craniofacial deformities and syndromes, including cleft lip and/ or palate
• Cigarette or vape smokers

Sponsors & Collaborators

• University of Malaya: lead

Study Sites (1)

Faculty of Dentistry, Universiti Malaya

Kuala Lumpur, Kuala Lumpur, 50603, Malaysia

Location

Central Study Contacts

ZHI MEI CHIA

CONTACT

+60143438922; s2102418@siswa.um.edu.my

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 12, 2026
• First Posted: June 25, 2026
• Study Start: July 1, 2026
• Primary Completion (Estimated): June 30, 2027
• Study Completion (Estimated): September 30, 2027
• Last Updated: July 23, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

MY (1)